{"id":1400,"date":"2016-04-13T15:46:51","date_gmt":"2016-04-13T15:46:51","guid":{"rendered":"https:\/\/courses.lumenlearning.com\/geologyxwaymakerxmaster\/?post_type=chapter&#038;p=1400"},"modified":"2019-09-27T14:52:28","modified_gmt":"2019-09-27T14:52:28","slug":"outcome-scientific-tools","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/colorado-wmopen-geology\/chapter\/outcome-scientific-tools\/","title":{"raw":"Geologic Tools and Equipment","rendered":"Geologic Tools and Equipment"},"content":{"raw":"<h2>Geological Tools -- both physical and conceptual.<\/h2>\r\n<h2><span style=\"float: none;background-color: transparent;color: #373d3f;cursor: text;font-family: 'proxima-nova',sans-serif;font-size: 16px;font-style: normal;font-variant: normal;font-weight: 400;letter-spacing: normal;text-align: left;text-decoration: none;text-indent: 0px\">Geologic tools encompass both <em>physical tools<\/em> (equipment, devices, gadgets) and <em>conceptual tools<\/em> (how to \"think\" about rocks and naturally occurring earth structures).<\/span><\/h2>\r\n<div class=\"textbox learning-objectives\">\r\n<h3>What You'll Learn to Do<\/h3>\r\n<ul>\r\n \t<li>Discuss several tools and their use in geology.<\/li>\r\n \t<li>Understand how to read various maps.<\/li>\r\n \t<li>Find a location using longitude and latitude.<\/li>\r\n \t<li>Identify commonly used geological models.<\/li>\r\n<\/ul>\r\n<\/div>\r\n<div id=\"post-1398\" class=\"type-1 post-1398 chapter type-chapter status-publish hentry\">\r\n<div class=\"entry-content\">\r\n<h2><\/h2>\r\n<h2>Geologic Tools<\/h2>\r\nGeologists use a lot of tools to aid their studies.\r\nCommon tools include GPS, compasses, rock hammers, hand lenses, and field books.\r\n<h3>GPS<\/h3>\r\n<span style=\"float: none;background-color: transparent;color: #373d3f;cursor: text;font-family: 'proxima-nova',sans-serif;font-size: 16px;font-style: normal;font-variant: normal;font-weight: 400;letter-spacing: normal;text-align: left;text-decoration: none;text-indent: 0px\">Whenever geologists are \"in the field\" trying to acquire information about rocks, fossils, structures (how rocks are tilted or deformed), and really any natural features, the first and foremost requirement is to know where one is located.\u00a0 Today, thanks to a collection of approximately 30 satellites in geosynchronous orbits, we are able to easily and accurately identify position with GPS devices.\r\nIn a nutshell, GPS receivers determine their distance from satellites using travel time differences--\u00a0 if a satellite is close, then signals are received more quickly than if the satellite is far away.\u00a0 Time differences provide distance to satellite.\r\nAs long as several satellites are within range and sight, the GPS device can generate mathematical triangulation calculations and establish position.<\/span>\r\n\r\n<\/div>\r\n<\/div>\r\n<h2><a href=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/2666\/2016\/04\/31155412\/untitled.png\"><img class=\"alignnone size-medium wp-image-3342\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/2666\/2016\/04\/31155412\/untitled-300x152.png\" alt=\"\" width=\"300\" height=\"152\" \/><\/a><\/h2>\r\n&nbsp;\r\n<h3>Compass<\/h3>\r\nThe magnetic compass is a key tool for geologists.\r\n<div id=\"post-1398\" class=\"type-1 post-1398 chapter type-chapter status-publish hentry\">\r\n<div class=\"entry-content\">\r\n\r\nIn the past (and occasionally today), the compass can help with identification of one's location, but it is much more commonly used to assess the orientation of some geologic feature.\r\nIt might be as simple as the orientation of a ridge or valley, but it could also be a bedding plane (within layered rocks) or a fault zone or the contact between two different rock types.\r\nUltimately, this sort of information finds it way on to geology maps.\r\nGeologists can use geologic maps as a means to interpret subsurface features and the nature of past deformation and rock movement.\r\n<h4><span id=\"Modern_geological_compasses\" class=\"mw-headline\">Modern Geological Compasses<\/span><\/h4>\r\nHere pictures of the sort of compass that a geologist might use.\r\nMost importantly, the geologic compass is not only useful in determining N-S-E-W directions, but also the \"dip\"\u00a0 (angle of deviation from a horizontal plane) that rocks or layers might show.\r\nIf you take a geology lab class, you may learn about how geologists measure strike and dip.\r\nThe \"direction\" of a rock surface (basically the intersection of the rock plane with a horizontal line) is called strike.\r\nThe deviation from of the rock surface from a horizontal plane is called dip.\r\n<table>\r\n<tbody>\r\n<tr>\r\n<td>\r\n\r\n[caption id=\"attachment_1710\" align=\"alignnone\" width=\"300\"]<img class=\"wp-image-1710\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/115\/2016\/05\/20174840\/FPM_compass_with_annotation_en.svg_.png\" alt=\"Setup of a modern geological compass after Prof. Clar (Freiberger), total view\" width=\"300\" height=\"200\" \/> Setup of a modern geological compass after Prof. Clar (Freiberger), total view[\/caption]<\/td>\r\n<td>\r\n\r\n[caption id=\"attachment_1711\" align=\"alignnone\" width=\"300\"]<img class=\"wp-image-1711\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/115\/2016\/05\/20174857\/FPM_compass_with_annotation_top_view_en.svg_.png\" alt=\"top view of compass\" width=\"300\" height=\"200\" \/> top view[\/caption]<\/td>\r\n<td>\r\n\r\n[caption id=\"attachment_1712\" align=\"alignnone\" width=\"300\"]<img class=\"wp-image-1712\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/115\/2016\/05\/20174915\/FPM_compass_with_annotation_bottom_side_en.svg_.png\" alt=\"bottom side of the compass\" width=\"300\" height=\"200\" \/> bottom side[\/caption]<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<\/div>\r\n<\/div>\r\n&nbsp;\r\n\r\n[caption id=\"attachment_1715\" align=\"alignleft\" width=\"400\"]<img class=\"wp-image-1715\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/115\/2016\/05\/20175046\/714px-StrikeLineDip.jpg\" alt=\"Strike line and dip of a plane describing attitude relative to a horizontal plane and a vertical plane perpendicular to the strike line\" width=\"400\" height=\"336\" \/> <span style=\"float: none;background-color: transparent;color: #373d3f;cursor: text;font-family: 'proxima-nova',sans-serif;font-size: 16px;font-style: normal;font-variant: normal;font-weight: 400;letter-spacing: normal;text-align: left;text-decoration: none;text-indent: 0px\">The gray surface (plane) is the \"surface of interest\"-- a sedimentary layer, or a fault zone, or any planar feature. The intersection of our \"surface of interest\" with a horizontal plane yields a line, and the compass direction of that line is <strong>strike<\/strong>.\u00a0 We also speak of the angular deviation between our \"surface of interest\" and the horizontal, which we call the <strong>dip<\/strong>.<\/span>[\/caption]\r\n\r\n<div id=\"post-1398\" class=\"type-1 post-1398 chapter type-chapter status-publish hentry\">\r\n<div class=\"entry-content\">\r\n<div class=\"mceTemp\"><\/div>\r\n<h4><\/h4>\r\n<h4><span style=\"float: none;background-color: #ffffff;color: #373d3f;cursor: text;font-family: 'proxima-nova',sans-serif;font-size: 16px;font-style: normal;font-variant: normal;font-weight: 400;letter-spacing: normal;text-align: left;text-decoration: none;text-indent: 0px\">Note: With the advent of the smartphone, geological compass programs based on the 3-axis teslameter and the 3-axis accelerometer have also begun to appear. These compass programs compute plane and lineation orientations from the accelerometer and magnetometer data, and permit rapid collection of many measurements. However, some problems are potentially present. Smartphones produce a strong magnetic field of their own which must be compensated by software.<\/span><\/h4>\r\n<h4><\/h4>\r\n<h4><\/h4>\r\n<h4><\/h4>\r\n<h4><\/h4>\r\n<h4><\/h4>\r\n<h4><\/h4>\r\n<h4><\/h4>\r\n<h4><\/h4>\r\n<h4><\/h4>\r\n<h3>Rock Hammers<\/h3>\r\n[caption id=\"attachment_1717\" align=\"alignright\" width=\"300\"]<img class=\"wp-image-1717\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/115\/2016\/05\/20175553\/Turonian_Jerusalem_Stone_031612.jpg\" alt=\"A geologist's hammer used to break up rocks, as well as a scale in the photograph\" width=\"300\" height=\"206\" \/> A geologist's hammer used to break up rocks, as well as a scale in the photograph[\/caption]\r\n\r\nA <b>geologist's hammer<\/b>, <b>rock hammer<\/b>, <b>rock pick<\/b>, or <b>geological pick<\/b> is a hammer used for splitting and breaking rocks. In field geology, they are used to obtain a fresh surface of a rock to determine its composition, nature, mineralogy, history, and field estimate of rock strength. In fossil and mineral collecting, they are employed to break rocks with the aim of revealing fossils inside. Geologist's hammers are also sometimes used for scale in a photograph.\r\n\r\n&nbsp;\r\n<h3>Hand Lenses<\/h3>\r\n[caption id=\"attachment_1718\" align=\"alignright\" width=\"300\"]<img class=\"wp-image-1718\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/115\/2016\/05\/20180023\/LoupeEZ.jpg\" alt=\"Loupe used by a geologist\" width=\"300\" height=\"285\" \/> Loupe used by a geologist[\/caption]\r\n\r\nThe hand lens is an old and vital geological field tool used to identify small mineral crystals, fossils, and\/or structures in rocks.\u00a0It\u00a0is a simple, small magnification device typically generating magnification around 5-15x. Unlike a magnifying glass, a loupe does not have an attached handle, and its\u00a0focusing lens(es) are contained in an opaque cylinder or cone or fold into an enclosing housing that protects the lenses when not in use.\r\n<h3>Field Books and Notes<\/h3>\r\n<strong>Field books<\/strong>\u00a0are used to take fieldnotes; they can be anything from a composition type notebook to a spiral.\u00a0 Many are specialized, sturdy and somewhat water resistant.\r\n\r\nNotes taken in the field are surprisingly useful later on when downloading data into digital and graphical formats.\r\nGeology is very contextual, in the sense that our interpretations of geologic processes depends on conditions and locations!\r\n\r\nThese notes are of course key to any science that uses descriptive field work-- for example, ethnography, biology, ecology, and archaeology.\r\nNotes might fall into two categories:\r\n<ul>\r\n \t<li>Descriptive information is factual data that is being recorded. Factual data includes time and date, the state of the physical setting, social environment, descriptions of the subjects being studied and their roles in the setting, and the impact that the observer may have had on the environment.<\/li>\r\n \t<li>Reflective information is the observer's reflections about the observation being conducted. These reflections are ideas, questions, concerns, and other related thoughts.<\/li>\r\n<\/ul>\r\nFieldnotes often include sketches, diagrams, and other drawings.\r\n<h2>Maps<\/h2>\r\nMaps are essential tools in geology because they describe the features of earth's surface!\u00a0 Geology lab courses expose students to both topographic and geologic maps.\u00a0 Below are a few notes on these.\r\n<h3>Topographic Maps<\/h3>\r\n[caption id=\"attachment_1430\" align=\"alignright\" width=\"400\"]<img class=\"wp-image-1430\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/115\/2016\/04\/14222609\/Map.png\" alt=\"A complex map of Yellowstone. There are several natural features on the map, including springs, geysers, and plains.\" width=\"400\" height=\"378\" \/> Figure 1. Map of Yellowstone.[\/caption]\r\n\r\nA <strong>topographic map<\/strong>\u00a0(like the one in figure 1) is one type of map used by geologists. Topographic maps show the three-dimensional shape of the land and features on the surface of the earth. Topographic maps are also used by hikers, planners who make decisions on zoning and construction permits, government agencies involved in land use planning and hazard assessments, and civil engineers. The topographic maps drawn and published by the U. S. Geological Survey portray the grids that are used on deeds to identify the location of real estate, so homeowners and property owners sometimes find it useful to refer to topographic maps of their area.\r\n\r\nTopographic maps make use of contour lines to depict elevations above sea level. Each contour line represents a line of constant elevation-- running your finger along a line, or actually going out and walking a line, means that your elevation of above sea level remains constant. Those proficient with \"topo maps\" are able to visualize three dimensional features like mountains, plains, ridges, or valleys simply by looking at the 2-D image.\r\n\r\nWhy do geologists care about 3-D structures?\u00a0 Earth's 3-D surface features are fundamentally a result of some combination of rock type, rock deformation, and\/or erosion!\r\n\r\nThe topographic map is the starting point for a geologic map.\u00a0 A geologic map is (at its essence) simply a topographic map that has been colored to show the location of different rock types; symbols are added to show structures like rock breaking planes (faults and fractures) and rock bends (folds).\r\n\r\nNote On USGS Maps:\r\nStandard United States Geological Survey topographic maps cover a quadrangle. A map quadrangle spans a fraction of a degree of longitude east-to-west and the same fraction of a degree of latitude north-to-south. Because lines of longitude degrees (also called meridians) in the Northern Hemisphere come closer and closer together the nearer they get to the North Pole, whereas lines of latitude degrees remain the same distance apart as they circle the earth, quadrangle maps span less distance east-to-west than they do north-to-south.\r\n\r\nTwo common quadrangle sizes are 7.5 minutes (1\/8 of a degree), and 15 minutes (1\/4 of a degree).\r\n<div class=\"textbox key-takeaways\">\r\n<h3>Name, Size, and Latitude-Longitude of a Topographic Map Quadrangle<\/h3>\r\n<img class=\"aligncenter size-full wp-image-1561\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/115\/2016\/05\/10174754\/mapName.gif\" alt=\"A map portion. It reads Juniper Quadrangle, Oregon\u2013Washington. 7.5 minute series (topographic). Below this is the lines of the top right corner of the map. There are markings indicating the east at 119 degrees 00' and the north ad 46 degrees 00'. The corner is labelled Wallula 1:125,000).\" width=\"773\" height=\"228\" \/>\r\n\r\n&nbsp;\r\n\r\n<\/div>\r\n<div class=\"textbox key-takeaways\">\r\n<h3>Map Scale, Contour Interval, and Magnetic Declination<\/h3>\r\n<img class=\"aligncenter size-full wp-image-1562\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/115\/2016\/05\/10175824\/mapScale.gif\" alt=\"The scale at the bottom of a map. The bottom edge of the map can be seen. 5\u2019 and 2\u201930\u2019\u2019 are noted on the edge of the map. On the left side of this clip, you can read 360,000 Feet (Oreg.). In the center of the bottom edge it reads Umatilla 1:125,000. The scale is stated to be 1:24,000. There are three scale bars indicating the length on the map that equals a mile, 7000 feet, and 1 kilometer. The contours interval is 20 feet. Datum is mean sea level. Depth curves and sounds in feet; datum is normal pool elevation 340 feet. The approximate man declination, 1962 measures a 20 and a half degree difference between true north and magnetic north. Below this is a short passage that reads as follows: This map complies with National map accuracy standards. For sale by the U.S. Geological Survey, Denver 25, Colorado or Washington 25, D.C. A folder describing topographic maps and symbols is available on request.\" width=\"1124\" height=\"406\" \/>\r\n\r\nImportant information is shown at the bottom of a USGS quadrangle map, including the map scale, the contour interval, and the magnetic declination. The image above is from the bottom of the Juniper 7.5 minute quadrangle. It tells you, among other things:\r\n<ol>\r\n \t<li>The map scale. The map scale is listed in terms of the fractional scale as 1:24,000. This means that 1 inch on the map corresponds to 24,000 inches in the real world represented by the map, or 1 cm equals 24,000 cm; in other words, distances on the map have been shrunk by a factor of 24,000 from their real-world size. Beneath the fractional scale, the map scale is also depicted a different way, in bar scales using three different units. One of the bar scales is in miles, one is in units of thousands of feet, and one is in kilometers.<\/li>\r\n \t<li>The contour interval, the difference in elevation between adjacent contour lines on the map, is listed below the map scale as 20 feet.<\/li>\r\n \t<li>Declination refers to the \"drift\" or change in relative position of geographic (rotation axis) pole with the magnetic pole.\u00a0 These are generally close in terms of location, but they are rarely exactly coincident.<\/li>\r\n<\/ol>\r\n<\/div>\r\n<h4>Constructing a Topographic Profile<\/h4>\r\nIn the diagram below, you see an idealized topo map, with a line drawn on it, from A to A'.\r\nIt's often useful (certainly by geologists but many other users, including hikers and mountain bikers!) to construct a kind of graph that shows the \"ups and downs\" of topography across a line like A-A', and called a topographic profile.\r\nAlthough tedious to do by hand (many computer programs can generate these graphs), a topographic profiles is simply a graph showing the various surface elevation changes as one moves from point A to A'\r\n\r\n<img class=\"aligncenter wp-image-1566\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/115\/2016\/05\/10184643\/tppD.gif\" alt=\"The same map and grid. The lines in the grid have been connected, to show a slope, which resembles the side view of a mountain.\" width=\"600\" height=\"402\" \/>\r\n<h5>Step 5<\/h5>\r\nHere's a completed topo profile.\r\n\r\n<img class=\"aligncenter wp-image-1567\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/115\/2016\/05\/10184707\/tppE.gif\" alt=\"The same map and grid. The guide lines have been removed, so it is just the map and a representation of the slope.\" width=\"600\" height=\"411\" \/>\r\n\r\nNotice on the topographic profile constructed above that the peak of the hill is above 520 ft, but below 540 ft. Similarly, the ends of the profile are below 400 ft but above 380. This is consistent with the elevations of those parts of the line of profile on the map.\r\n\r\nNote that the vertical scale on the profile is very different from the horizontal scale on the map. In this example, the map covers 0.25 miles horizontally in less distance than the profile covers 100 feet vertically. As a result, the topographic profile is greatly exaggerated vertically. In an actual view of the hill, looking at it from the side, it would not look nearly as steep as it does in the topographic profile that we have constructed.\r\n\r\nComparing the profile to the topographic map notice that the hill is steeper on the west (left) side than on the east (right) side. This is consistent with the contour lines being spaced more closely on the west side of the hill and farther apart on the east side of the hill.\u00a0 Closely spaced contours indicate steep slopes!\r\n<h3>Bathymetric Maps<\/h3>\r\n[caption id=\"attachment_1560\" align=\"alignright\" width=\"300\"]<img class=\"wp-image-1560\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/115\/2016\/05\/10174339\/LoihiBathemetric.jpg\" alt=\"Figure 3. Loihi volcano growing on the flank of Kilauea volcano in Hawaii. Black lines in the inset show the land surface above sea level and blue lines show the topography below sea level. Click on the image to view a larger version.\" width=\"300\" height=\"362\" \/> Figure 3. Loihi volcano growing on the flank of Kilauea volcano in Hawaii. Black lines in the inset show the land surface above sea level and blue lines show the topography below sea level. Click on the image to view a larger version.[\/caption]\r\n<p id=\"x-ck12-YzMyZDNkZTcxMTZjM2Y0YTU5ZjU1ZmJhNjZjODdlYmE.-k5s\">A <strong><span class=\"vocab_term\">bathymetric map<\/span><\/strong> is like a <span class=\"vocab_term\">topographic map<\/span> with the contour lines representing depth below sea level, rather than height above. Numbers are low near sea level and become higher with depth.<\/p>\r\n<p id=\"x-ck12-ZTViNmIyY2EyZDYxYmUwYWRiNjkxZmI0YTAyYWY5NzY.-10m\">Kilauea is the youngest volcano found above sea level in Hawaii. On the flank of Kilauea is an even younger volcano called Loihi. The bathymetric map pictured in figure 3 shows the form of Loihi.<\/p>\r\n\r\n<h3>Geologic Maps<\/h3>\r\nA <strong>geologic map<\/strong> is simply a topographic map with added information about rocks and rock features.\r\nThe first thing one notices about a geologic map is that they are quite colorful.\u00a0 Each color represents a particular rock type or rock age-group.\u00a0 Additionally, various symbols are imposed on the map which indicates rock features such as folds (bent or warped rocks) and faults (planar to semi-planar zones of rock breakage).\u00a0 All of these colors and symbols are reviewed in the map key or legend.\r\n\r\nA particular color zone on the map represents a rock unit that can be consistently recognized, traced across a landscape, and described, such that in the hands of another geologist these units can be identified and verified.\r\n\r\n[caption id=\"attachment_1435\" align=\"alignright\" width=\"429\"]<img class=\"size-full wp-image-1435\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/115\/2016\/04\/14223303\/geologic.jpg\" alt=\"geologic map of the region around Old Faithful, Yellowstone National Park\" width=\"429\" height=\"500\" \/> Figure 4. A geologic map of the region around Old Faithful, Yellowstone National Park.[\/caption]\r\n\r\nGeologic maps are useful inasmuch as they provide a visual image of key geologic features over a broad area.\r\nThey can be used to generate \"cross sections\" showing the subsurface geology and orientation of rocks units at depth.\r\nWhy is all this useful?\r\nFirstly, because this is the starting point for making interpretations about the geologic history of a region (including what sort of conditions were at the surface during past eras, and also what sort of forces contorted the rocks at depth).\u00a0 Secondly, there are all kinds of <span style=\"float: none;background-color: transparent;color: #373d3f;cursor: text;font-family: 'proxima-nova',sans-serif;font-size: 16px;font-style: normal;font-variant: normal;font-weight: 400;letter-spacing: normal;text-align: left;text-decoration: none;text-indent: 0px\">practical applications, whereby geologic maps are crucial-- such as zoning, civil engineering, groundwater and hazard assessment.<\/span>\r\n\r\n.\r\n<h4><\/h4>\r\n<h4>What do we find on a geologic map?<\/h4>\r\nThe legend or key to a geologic map is usually printed on the same page as the map and follows a customary format. The symbol for each rock or sediment unit is shown in a box next to its name and brief description. These symbols are stacked in age sequence from oldest at the bottom to youngest at the top. The geologic era, or period, or epoch--the geologic age--is listed for each rock unit in the key. By stacking the units in age sequence from youngest at the top to oldest at the bottom, and identifying which interval of geologic time each unit belongs to, the map reader can quickly see the age of each rock or sediment unit. The map key also contains a listing and explanation of the symbols shown on the map, such as the symbols for different types of faults and folds. See the Table of Geologic Map Symbols\u00a0for pictures and an overview of the map symbols, including strikes and dips, faults, folds, and an overview.\r\n<h4>Table of Geologic Map Symbols<\/h4>\r\n<table>\r\n<thead>\r\n<tr>\r\n<th colspan=\"3\">Strike and Dip Symbols<\/th>\r\n<\/tr>\r\n<tr>\r\n<td colspan=\"3\"><em>Strike and dip are a way of representing the three-dimensional orientation of a planar surface on a two-dimensional map. The strike is the compass direction of a horizontal line on the plane. All the horizontal lines on a plane are parallel, so they all have the same characteristic compass direction. The dip is the angle at which the plane slopes downhill from the horizontal, at its maximum slope, which is at right angles (90\u00ba) from strike.<\/em><\/td>\r\n<\/tr>\r\n<\/thead>\r\n<tbody>\r\n<tr>\r\n<th>Map Symbol<\/th>\r\n<th>Definition<\/th>\r\n<th>Explanation of symbol<\/th>\r\n<\/tr>\r\n<tr>\r\n<td align=\"center\"><img class=\"alignnone wp-image-283 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/781\/2015\/07\/23111500\/SD-tilted.gif\" alt=\"vertical line with a small horizontal line on its right side labeled 38\" width=\"55\" height=\"54\" \/><\/td>\r\n<td align=\"center\">strike and dip of beds other than horizontal or vertical<\/td>\r\n<td>\r\n<ul>\r\n \t<li>strike (longer line) is horizontal line on bedding plane<\/li>\r\n \t<li>strike parallels nearby contacts between stratified rocks<\/li>\r\n \t<li>dip shows which way beds run downhill<\/li>\r\n \t<li>dip angle, number at end of dip symbol, is how much beds tilt down from horizontal<\/li>\r\n<\/ul>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td align=\"center\"><img class=\"alignnone wp-image-284 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/781\/2015\/07\/23111500\/SD-horizontal.gif\" alt=\"circle with a t cross inside\" width=\"55\" height=\"58\" \/><\/td>\r\n<td align=\"center\">horizontal beds<\/td>\r\n<td>\r\n<ul>\r\n \t<li>because the bed is horizontal it strikes in all directions<\/li>\r\n \t<li>because the bed is horizontal, the dip is 0%<\/li>\r\n<\/ul>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td align=\"center\"><img class=\"alignnone wp-image-285 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/781\/2015\/07\/23111501\/SD-vertical.gif\" alt=\"vertical line with a small horizontal line crossing the middle\" width=\"57\" height=\"59\" \/><\/td>\r\n<td align=\"center\">strike and dip of vertical beds<\/td>\r\n<td>\r\n<ul>\r\n \t<li>strike (longer line) is horizontal line on bedding plane<\/li>\r\n \t<li>because the bed dips vertically (has a 90% dip), it dips equally in either direction at right angles to strike, so the dip line is shown extending in both directions<\/li>\r\n<\/ul>\r\n<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<table>\r\n<thead>\r\n<tr>\r\n<th colspan=\"5\">Geologic Fault Symbols<\/th>\r\n<\/tr>\r\n<\/thead>\r\n<tbody>\r\n<tr>\r\n<th width=\"10%\">Type of Fault<\/th>\r\n<th width=\"10%\">Map Symbol<\/th>\r\n<th width=\"30%\">Definition<\/th>\r\n<th width=\"10%\">Type of Regional Stress<\/th>\r\n<th width=\"30%\">Geologic Associations<\/th>\r\n<\/tr>\r\n<tr>\r\n<td align=\"center\">normal<\/td>\r\n<td align=\"center\"><img class=\"alignnone wp-image-286 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/781\/2015\/07\/23111501\/Normal.jpg\" alt=\"horizontal line with a U above and D below. U on uplifted side, D on down-dropped side.\" width=\"56\" height=\"75\" \/><\/td>\r\n<td align=\"center\">hanging wall down, footwall up<\/td>\r\n<td align=\"center\">tension<\/td>\r\n<td>\r\n<ul>\r\n \t<li>zones of crustal extension<\/li>\r\n \t<li>divergent plate boundaries<\/li>\r\n \t<li>edges of horsts and grabens<\/li>\r\n \t<li>Basin and Range region<\/li>\r\n<\/ul>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td align=\"center\">detachment<\/td>\r\n<td align=\"center\">\u00a0<img class=\"alignnone wp-image-287 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/781\/2015\/07\/23111502\/Detachment.jpg\" alt=\"rectangles on horizontal line (rectangles on upper plate)\" width=\"56\" height=\"75\" \/><\/td>\r\n<td align=\"center\">low-angle normal fault, footwall\u2014gneiss, hanging wall\u2014shallow-crust rocks<\/td>\r\n<td align=\"center\">tension<\/td>\r\n<td>\r\n<ul>\r\n \t<li>boundaries of metamorphic core complexes<\/li>\r\n<\/ul>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td align=\"center\">thrust<\/td>\r\n<td align=\"center\"><img class=\"alignnone wp-image-274 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/781\/2015\/07\/23111459\/Convergent.jpg\" alt=\"triangles on horizontal line (triangles on upper plate)\" width=\"56\" height=\"75\" \/><\/td>\r\n<td align=\"center\">hanging wall up, footwall down<\/td>\r\n<td align=\"center\">compression<\/td>\r\n<td>\r\n<ul>\r\n \t<li>zones of crustal compression<\/li>\r\n \t<li>convergent plate boundaries<\/li>\r\n<\/ul>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td align=\"center\">reverse<\/td>\r\n<td align=\"center\">\u00a0<img class=\"wp-image-274 size-full alignnone\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/781\/2015\/07\/23111459\/Convergent.jpg\" alt=\"triangles on horizontal line (triangles on upper plate)\" width=\"56\" height=\"75\" \/><\/td>\r\n<td align=\"center\">high-angle (45\u00b0 or more dip) thrust fault<\/td>\r\n<td align=\"center\">compression<\/td>\r\n<td>\r\n<ul>\r\n \t<li>zones of crustal compression<\/li>\r\n \t<li>convergent plate boundaries<\/li>\r\n<\/ul>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td align=\"center\">strike-slip<\/td>\r\n<td align=\"center\"><img class=\"alignnone wp-image-273 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/781\/2015\/07\/23111459\/Transform.jpg\" alt=\"two half-arrows pointing in opposite directions\" width=\"56\" height=\"75\" \/><\/td>\r\n<td align=\"center\">rocks on either side move horizontally in opposite directions<\/td>\r\n<td align=\"center\">shear<\/td>\r\n<td>\r\n<ul>\r\n \t<li>continental margins undergoing oblique (not straight on) plate convergence<\/li>\r\n \t<li>transform plate boundaries<\/li>\r\n<\/ul>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td align=\"center\">oblique-slip<\/td>\r\n<td align=\"center\"><img class=\"alignnone wp-image-288 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/781\/2015\/07\/23111502\/Oblique.jpg\" alt=\"two half-arrows pointing in opposite directions. U on uplifted side, D on down-dropped side\" width=\"56\" height=\"75\" \/><\/td>\r\n<td align=\"center\">combines horizontal and vertical motion<\/td>\r\n<td align=\"center\">combination<\/td>\r\n<td>\r\n<ul>\r\n \t<li>orogenic mountain belts<\/li>\r\n \t<li>continental margins undergoing oblique (not straight on) plate convergence<\/li>\r\n<\/ul>\r\n<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<table>\r\n<thead>\r\n<tr>\r\n<th colspan=\"4\">Geologic Fold Symbols<\/th>\r\n<\/tr>\r\n<\/thead>\r\n<tbody>\r\n<tr>\r\n<th>Type of Fold<\/th>\r\n<th>Map Symbol<\/th>\r\n<th>Definition<\/th>\r\n<th>Appearance of Beds in Map View<\/th>\r\n<\/tr>\r\n<tr>\r\n<td align=\"center\">anticline<\/td>\r\n<td align=\"center\"><img class=\"alignnone wp-image-290 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/781\/2015\/07\/23111502\/Anticline.jpg\" alt=\"horizontal line with a vertical line crossing it. There are arrows on both ends of the vertical line pointing away from the horizontal line.\" width=\"56\" height=\"75\" \/><\/td>\r\n<td align=\"center\">up fold<\/td>\r\n<td>\r\n<ul>\r\n \t<li>roughly parallel stripes<\/li>\r\n \t<li>dip away from center (away from axis)<\/li>\r\n \t<li>oldest at center (along axis)<\/li>\r\n \t<li>youngest farthest from center<\/li>\r\n<\/ul>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td align=\"center\">plunging anticline<\/td>\r\n<td align=\"center\"><img class=\"alignnone wp-image-291 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/781\/2015\/07\/23111502\/PlungingAnticline.jpg\" alt=\"horizontal arrow pointing to the right with a vertical line crossing it. There are arrows on both ends of the vertical line pointing away from the horizontal line. \" width=\"56\" height=\"75\" \/><\/td>\r\n<td align=\"center\">up fold with tilted axis<\/td>\r\n<td>\r\n<ul>\r\n \t<li>roughly a U-shaped pattern<\/li>\r\n \t<li>plunges in direction U points<\/li>\r\n \t<li>oldest at center (along axis)<\/li>\r\n \t<li>youngest farthest from center<\/li>\r\n<\/ul>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td align=\"center\">syncline<\/td>\r\n<td align=\"center\"><img class=\"alignnone wp-image-292 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/781\/2015\/07\/23111503\/Syncline.jpg\" alt=\"Horizontal line with a vertical line crossing it. There are arrows on the internal ends of the vertical line pointing at the horizontal line.\" width=\"56\" height=\"75\" \/><\/td>\r\n<td align=\"center\">down fold<\/td>\r\n<td>\r\n<ul>\r\n \t<li>roughly parallel stripes<\/li>\r\n \t<li>dip toward center (toward axis)<\/li>\r\n \t<li>oldest farthest from center<\/li>\r\n \t<li>youngest at center (along axis)<\/li>\r\n<\/ul>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td align=\"center\">plunging syncline<\/td>\r\n<td align=\"center\"><img class=\"alignnone wp-image-293 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/781\/2015\/07\/23111503\/PlungingSyncline.jpg\" alt=\"Horizontal arrow with a vertical line crossing it. There are arrows on the internal ends of the vertical line pointing at the horizontal line.\" width=\"56\" height=\"75\" \/><\/td>\r\n<td align=\"center\">down fold with tilted axis<\/td>\r\n<td>\r\n<ul>\r\n \t<li>roughly a U-shaped pattern<\/li>\r\n \t<li>plunges in direction U opens<\/li>\r\n \t<li>oldest farthest from center<\/li>\r\n \t<li>youngest at center (along axis)<\/li>\r\n<\/ul>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td align=\"center\">monocline<\/td>\r\n<td align=\"center\"><img class=\"alignnone wp-image-294 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/781\/2015\/07\/23111503\/Monocline.jpg\" alt=\"Horizontal line with a vertical line crossing it. There is an arrow on the top end of the vertical line.\" width=\"56\" height=\"75\" \/><\/td>\r\n<td align=\"center\">strata tilted in one direction<\/td>\r\n<td>\r\n<ul>\r\n \t<li>all dip in same direction<\/li>\r\n<\/ul>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td align=\"center\">structural dome<\/td>\r\n<td align=\"center\"><img class=\"alignnone wp-image-295 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/781\/2015\/07\/23111503\/StructuralDome.gif\" alt=\"Horizontal arrow pointing to the right and the left with a vertical line crossing it. There are arrows on both ends of the vertical line pointing away from the horizontal line.\" width=\"56\" height=\"75\" \/><\/td>\r\n<td align=\"center\">upward bulge in layered rocks<\/td>\r\n<td>\r\n<ul>\r\n \t<li>roughly a bull's eye pattern<\/li>\r\n \t<li>dip away from center<\/li>\r\n \t<li>oldest in center<\/li>\r\n \t<li>youngest farthest from center<\/li>\r\n<\/ul>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td align=\"center\">structural basin<\/td>\r\n<td align=\"center\"><img class=\"alignnone wp-image-296 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/781\/2015\/07\/23111504\/StructuralBasin.jpg\" alt=\"Horizontal line with a vertical line crossing it. There are arrows on the internal ends of the vertical line pointing at the horizontal line. There are also arrows on the horizontal line pointing inward at the vertical line.\" width=\"56\" height=\"75\" \/><\/td>\r\n<td align=\"center\">downward bulge in layered rocks<\/td>\r\n<td>\r\n<ul>\r\n \t<li>roughly a bull's eye pattern<\/li>\r\n \t<li>dip toward center<\/li>\r\n \t<li>youngest in center<\/li>\r\n \t<li>oldest farthest from center<\/li>\r\n<\/ul>\r\n<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\nThe explanations of rock units are often given in a separate pamphlet that accompanies the map. The explanations include descriptions with enough detail for any geologist to be able to recognize the units and learn how their ages were determined.\r\n\r\nIf included, cross-sections are usually printed on the same page as the geologic map. They are important accompaniments to geologic maps, especially if the map focuses on the geology of the bedrock underneath the soil and loose sediments.\r\n<h4>Geologic Cross-Sections<\/h4>\r\nA geologic cross-section is a sideways view of a slice of the earth. It shows how the different types of rock are layered or otherwise configured, and it portrays geologic structures beneath the earth's surface, such as faults and folds. Geologic cross-sections are constructed on the basis of the geology mapped at the surface combined with an understanding of rocks in terms of physical behavior and three-dimensional structures.\r\n<h3>Summary<\/h3>\r\n<ul>\r\n \t<li>Earth scientists regularly use topographic, bathymetric, and geologic maps.<\/li>\r\n \t<li>Topographic maps reveal the shape of a landscape. Elevations indicate height above sea level.<\/li>\r\n \t<li>Bathymetric maps are like topographic maps of features found below the water. Elevations indicate depth below sea level.<\/li>\r\n \t<li>Geologic maps show rock units and geologic features like faults and folds.<\/li>\r\n<\/ul>\r\n&nbsp;\r\n<h3>Making MODELS as a Means to Do Science!<\/h3>\r\nA <strong>physical model<\/strong> is a representation of something using objects. It can be three-dimensional, like a globe. It can also be a two-dimensional drawing or diagram. Models are usually smaller and simpler than the real object. They most likely leave out some parts, but contain the important parts. In a good model the parts are made or drawn to scale. Physical models allow us to see, feel and move their parts. This allows us to better understand the real system.\r\n\r\nAn example of a physical model is a drawing of the layers of Earth (figure 6). A drawing helps us to understand the structure of the planet. Yet there are many differences between a drawing and the real thing. The size of a model is much smaller, for example. A drawing also doesn\u2019t give good idea of how substances move. Arrows showing the direction the material moves can help. A physical model is very useful but it can\u2019t explain the real Earth perfectly.\r\n\r\n[caption id=\"attachment_1440\" align=\"aligncenter\" width=\"777\"]<img class=\"size-full wp-image-1440\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/115\/2016\/04\/14224536\/Fig_2_5.png\" alt=\"Diagram showing the different layers of the earth. From the outside to the inside they are the crust, moho, upper mantle, lower mantle, D(double prime)-layer, outer core, liquid-solid boundary, and inner core.\" width=\"777\" height=\"415\" \/> Figure 6. Earth\u2019s Center.[\/caption]\r\n<h3>Ideas as Models<\/h3>\r\n[caption id=\"attachment_1441\" align=\"alignright\" width=\"192\"]<img class=\"size-full wp-image-1441\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/115\/2016\/04\/14224643\/collision.jpg\" alt=\"An illustration of a meteor a third of the size of the earth colliding with the planet.\" width=\"192\" height=\"154\" \/> Figure 7. A collision showing a meteor striking Earth.[\/caption]\r\n\r\nSome models are based on an idea that helps scientists explain something. A good idea explains all the known facts. An example is how Earth got its Moon. A Mars-sized planet hit Earth and rocky material broke off of both bodies (figure 7). This material orbited Earth and then came together to form the Moon. This is a model of something that happened billions of years ago. It brings together many facts known from our studies of the Moon's surface. It accounts for the chemical makeup of rocks from the Moon, Earth, and meteorites. The physical properties of Earth and Moon figure in as well. Not all known data fits this model, but much does. There is also more information that we simply don\u2019t yet know.\r\n<h3>Models that Use Numbers<\/h3>\r\nModels may use formulas or equations to describe something. Sometimes math may be the only way to describe it. For example, equations help scientists to explain what happened in the early days of the universe. The universe formed so long ago that math is the only way to describe it. A climate model includes lots of numbers, including temperature readings, ice density, snowfall levels, and humidity. These numbers are put into equations to make a model. The results are used to predict future climate. For example, if there are more clouds, does global temperature go up or down? Models are not perfect because they are simple versions of the real situation. Even so, these models are very useful to scientists. These days, models of complex things are made on computers.\r\n<h2>Geologic Modelling<\/h2>\r\n[caption id=\"attachment_1695\" align=\"alignright\" width=\"400\"]<img class=\"wp-image-1695\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/115\/2016\/05\/18204134\/Contour_map_software_screen-e1463604138754.jpg\" alt=\"Screenshot of a structure map generated by Contour map software for an 8500ft deep gas &amp; Oil reservoir in the Erath field, Vermilion Parish, Erath, Louisiana. The left-to-right gap, near the top of the contour map indicates a Fault line. This fault line is between the blue\/green contour lines and the purple\/red\/yellow contour lines. The thin red circular contour line in the middle of the map indicates the top of the oil reservoir. Because gas floats above oil, the thin red contour line marks the gas\/oil contact zone.\" width=\"400\" height=\"483\" \/> Figure 8. Geological mapping software displaying a screenshot of a structure map generated for an 8500ft deep gas &amp; Oil reservoir in the Erath field, Vermilion Parish, Erath, Louisiana. The left-to-right gap, near the top of the contour map indicates a Fault line. This fault line is between the blue\/green contour lines and the purple\/red\/yellow contour lines. The thin red circular contour line in the middle of the map indicates the top of the oil reservoir. Because gas floats above oil, the thin red contour line marks the gas\/oil contact zone.[\/caption]\r\n\r\n<strong>Geologic modelling<\/strong>, or <strong>Geomodelling<\/strong>, is the applied science of creating computerized representations of portions of the Earth's crust based on geophysical and geological observations made on and below the Earth surface. A Geomodel is the numerical equivalent of a three-dimensional geological map complemented by a description of physical quantities in the domain of interest. Geomodelling is related to the concept of Shared Earth Model; which is a multidisciplinary, interoperable and updatable knowledge base about the subsurface.\r\n\r\n[caption id=\"attachment_1698\" align=\"alignright\" width=\"400\"]<img class=\"wp-image-1698\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/115\/2016\/05\/18210402\/MODFLOW_3D_grid.png\" alt=\"Three-dimensional finite difference grid used in MODFLOW. \" width=\"400\" height=\"284\" \/> Figure 9. A 3D finite difference grid used in MODFLOW for simulating groundwater flow in an aquifer.[\/caption]\r\n\r\n&nbsp;\r\n<h4><\/h4>\r\n&nbsp;\r\n<h4><\/h4>\r\n&nbsp;\r\n\r\n&nbsp;\r\n\r\n[caption id=\"attachment_1699\" align=\"aligncenter\" width=\"781\"]<img class=\"size-full wp-image-1699\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/115\/2016\/05\/18210540\/781px-Gravity_Highs.jpg\" alt=\"Gravity Highs over the Mardin Uplift\" width=\"781\" height=\"600\" \/> Figure 10. Gravity Highs[\/caption]\r\n<ul>\r\n \t<li><\/li>\r\n<\/ul>\r\n&nbsp;\r\n<ul>\r\n \t<li><\/li>\r\n<\/ul>\r\n:\r\n<ul>\r\n \t<li><\/li>\r\n<\/ul>\r\n&nbsp;\r\n\r\n<\/div>\r\n<\/div>","rendered":"<h2>Geological Tools &#8212; both physical and conceptual.<\/h2>\n<h2><span style=\"float: none;background-color: transparent;color: #373d3f;cursor: text;font-family: 'proxima-nova',sans-serif;font-size: 16px;font-style: normal;font-variant: normal;font-weight: 400;letter-spacing: normal;text-align: left;text-decoration: none;text-indent: 0px\">Geologic tools encompass both <em>physical tools<\/em> (equipment, devices, gadgets) and <em>conceptual tools<\/em> (how to &#8220;think&#8221; about rocks and naturally occurring earth structures).<\/span><\/h2>\n<div class=\"textbox learning-objectives\">\n<h3>What You&#8217;ll Learn to Do<\/h3>\n<ul>\n<li>Discuss several tools and their use in geology.<\/li>\n<li>Understand how to read various maps.<\/li>\n<li>Find a location using longitude and latitude.<\/li>\n<li>Identify commonly used geological models.<\/li>\n<\/ul>\n<\/div>\n<div id=\"post-1398\" class=\"type-1 post-1398 chapter type-chapter status-publish hentry\">\n<div class=\"entry-content\">\n<h2><\/h2>\n<h2>Geologic Tools<\/h2>\n<p>Geologists use a lot of tools to aid their studies.<br \/>\nCommon tools include GPS, compasses, rock hammers, hand lenses, and field books.<\/p>\n<h3>GPS<\/h3>\n<p><span style=\"float: none;background-color: transparent;color: #373d3f;cursor: text;font-family: 'proxima-nova',sans-serif;font-size: 16px;font-style: normal;font-variant: normal;font-weight: 400;letter-spacing: normal;text-align: left;text-decoration: none;text-indent: 0px\">Whenever geologists are &#8220;in the field&#8221; trying to acquire information about rocks, fossils, structures (how rocks are tilted or deformed), and really any natural features, the first and foremost requirement is to know where one is located.\u00a0 Today, thanks to a collection of approximately 30 satellites in geosynchronous orbits, we are able to easily and accurately identify position with GPS devices.<br \/>\nIn a nutshell, GPS receivers determine their distance from satellites using travel time differences&#8211;\u00a0 if a satellite is close, then signals are received more quickly than if the satellite is far away.\u00a0 Time differences provide distance to satellite.<br \/>\nAs long as several satellites are within range and sight, the GPS device can generate mathematical triangulation calculations and establish position.<\/span><\/p>\n<\/div>\n<\/div>\n<h2><a href=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/2666\/2016\/04\/31155412\/untitled.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-3342\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/2666\/2016\/04\/31155412\/untitled-300x152.png\" alt=\"\" width=\"300\" height=\"152\" \/><\/a><\/h2>\n<p>&nbsp;<\/p>\n<h3>Compass<\/h3>\n<p>The magnetic compass is a key tool for geologists.<\/p>\n<div id=\"post-1398\" class=\"type-1 post-1398 chapter type-chapter status-publish hentry\">\n<div class=\"entry-content\">\n<p>In the past (and occasionally today), the compass can help with identification of one&#8217;s location, but it is much more commonly used to assess the orientation of some geologic feature.<br \/>\nIt might be as simple as the orientation of a ridge or valley, but it could also be a bedding plane (within layered rocks) or a fault zone or the contact between two different rock types.<br \/>\nUltimately, this sort of information finds it way on to geology maps.<br \/>\nGeologists can use geologic maps as a means to interpret subsurface features and the nature of past deformation and rock movement.<\/p>\n<h4><span id=\"Modern_geological_compasses\" class=\"mw-headline\">Modern Geological Compasses<\/span><\/h4>\n<p>Here pictures of the sort of compass that a geologist might use.<br \/>\nMost importantly, the geologic compass is not only useful in determining N-S-E-W directions, but also the &#8220;dip&#8221;\u00a0 (angle of deviation from a horizontal plane) that rocks or layers might show.<br \/>\nIf you take a geology lab class, you may learn about how geologists measure strike and dip.<br \/>\nThe &#8220;direction&#8221; of a rock surface (basically the intersection of the rock plane with a horizontal line) is called strike.<br \/>\nThe deviation from of the rock surface from a horizontal plane is called dip.<\/p>\n<table>\n<tbody>\n<tr>\n<td>\n<div id=\"attachment_1710\" style=\"width: 310px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-1710\" class=\"wp-image-1710\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/115\/2016\/05\/20174840\/FPM_compass_with_annotation_en.svg_.png\" alt=\"Setup of a modern geological compass after Prof. Clar (Freiberger), total view\" width=\"300\" height=\"200\" \/><\/p>\n<p id=\"caption-attachment-1710\" class=\"wp-caption-text\">Setup of a modern geological compass after Prof. Clar (Freiberger), total view<\/p>\n<\/div>\n<\/td>\n<td>\n<div id=\"attachment_1711\" style=\"width: 310px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-1711\" class=\"wp-image-1711\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/115\/2016\/05\/20174857\/FPM_compass_with_annotation_top_view_en.svg_.png\" alt=\"top view of compass\" width=\"300\" height=\"200\" \/><\/p>\n<p id=\"caption-attachment-1711\" class=\"wp-caption-text\">top view<\/p>\n<\/div>\n<\/td>\n<td>\n<div id=\"attachment_1712\" style=\"width: 310px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-1712\" class=\"wp-image-1712\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/115\/2016\/05\/20174915\/FPM_compass_with_annotation_bottom_side_en.svg_.png\" alt=\"bottom side of the compass\" width=\"300\" height=\"200\" \/><\/p>\n<p id=\"caption-attachment-1712\" class=\"wp-caption-text\">bottom side<\/p>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n<p>&nbsp;<\/p>\n<div id=\"attachment_1715\" style=\"width: 410px\" class=\"wp-caption alignleft\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-1715\" class=\"wp-image-1715\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/115\/2016\/05\/20175046\/714px-StrikeLineDip.jpg\" alt=\"Strike line and dip of a plane describing attitude relative to a horizontal plane and a vertical plane perpendicular to the strike line\" width=\"400\" height=\"336\" \/><\/p>\n<p id=\"caption-attachment-1715\" class=\"wp-caption-text\"><span style=\"float: none;background-color: transparent;color: #373d3f;cursor: text;font-family: 'proxima-nova',sans-serif;font-size: 16px;font-style: normal;font-variant: normal;font-weight: 400;letter-spacing: normal;text-align: left;text-decoration: none;text-indent: 0px\">The gray surface (plane) is the &#8220;surface of interest&#8221;&#8211; a sedimentary layer, or a fault zone, or any planar feature. The intersection of our &#8220;surface of interest&#8221; with a horizontal plane yields a line, and the compass direction of that line is <strong>strike<\/strong>.\u00a0 We also speak of the angular deviation between our &#8220;surface of interest&#8221; and the horizontal, which we call the <strong>dip<\/strong>.<\/span><\/p>\n<\/div>\n<div id=\"post-1398\" class=\"type-1 post-1398 chapter type-chapter status-publish hentry\">\n<div class=\"entry-content\">\n<div class=\"mceTemp\"><\/div>\n<h4><\/h4>\n<h4><span style=\"float: none;background-color: #ffffff;color: #373d3f;cursor: text;font-family: 'proxima-nova',sans-serif;font-size: 16px;font-style: normal;font-variant: normal;font-weight: 400;letter-spacing: normal;text-align: left;text-decoration: none;text-indent: 0px\">Note: With the advent of the smartphone, geological compass programs based on the 3-axis teslameter and the 3-axis accelerometer have also begun to appear. These compass programs compute plane and lineation orientations from the accelerometer and magnetometer data, and permit rapid collection of many measurements. However, some problems are potentially present. Smartphones produce a strong magnetic field of their own which must be compensated by software.<\/span><\/h4>\n<h4><\/h4>\n<h4><\/h4>\n<h4><\/h4>\n<h4><\/h4>\n<h4><\/h4>\n<h4><\/h4>\n<h4><\/h4>\n<h4><\/h4>\n<h4><\/h4>\n<h3>Rock Hammers<\/h3>\n<div id=\"attachment_1717\" style=\"width: 310px\" class=\"wp-caption alignright\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-1717\" class=\"wp-image-1717\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/115\/2016\/05\/20175553\/Turonian_Jerusalem_Stone_031612.jpg\" alt=\"A geologist's hammer used to break up rocks, as well as a scale in the photograph\" width=\"300\" height=\"206\" \/><\/p>\n<p id=\"caption-attachment-1717\" class=\"wp-caption-text\">A geologist&#8217;s hammer used to break up rocks, as well as a scale in the photograph<\/p>\n<\/div>\n<p>A <b>geologist&#8217;s hammer<\/b>, <b>rock hammer<\/b>, <b>rock pick<\/b>, or <b>geological pick<\/b> is a hammer used for splitting and breaking rocks. In field geology, they are used to obtain a fresh surface of a rock to determine its composition, nature, mineralogy, history, and field estimate of rock strength. In fossil and mineral collecting, they are employed to break rocks with the aim of revealing fossils inside. Geologist&#8217;s hammers are also sometimes used for scale in a photograph.<\/p>\n<p>&nbsp;<\/p>\n<h3>Hand Lenses<\/h3>\n<div id=\"attachment_1718\" style=\"width: 310px\" class=\"wp-caption alignright\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-1718\" class=\"wp-image-1718\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/115\/2016\/05\/20180023\/LoupeEZ.jpg\" alt=\"Loupe used by a geologist\" width=\"300\" height=\"285\" \/><\/p>\n<p id=\"caption-attachment-1718\" class=\"wp-caption-text\">Loupe used by a geologist<\/p>\n<\/div>\n<p>The hand lens is an old and vital geological field tool used to identify small mineral crystals, fossils, and\/or structures in rocks.\u00a0It\u00a0is a simple, small magnification device typically generating magnification around 5-15x. Unlike a magnifying glass, a loupe does not have an attached handle, and its\u00a0focusing lens(es) are contained in an opaque cylinder or cone or fold into an enclosing housing that protects the lenses when not in use.<\/p>\n<h3>Field Books and Notes<\/h3>\n<p><strong>Field books<\/strong>\u00a0are used to take fieldnotes; they can be anything from a composition type notebook to a spiral.\u00a0 Many are specialized, sturdy and somewhat water resistant.<\/p>\n<p>Notes taken in the field are surprisingly useful later on when downloading data into digital and graphical formats.<br \/>\nGeology is very contextual, in the sense that our interpretations of geologic processes depends on conditions and locations!<\/p>\n<p>These notes are of course key to any science that uses descriptive field work&#8211; for example, ethnography, biology, ecology, and archaeology.<br \/>\nNotes might fall into two categories:<\/p>\n<ul>\n<li>Descriptive information is factual data that is being recorded. Factual data includes time and date, the state of the physical setting, social environment, descriptions of the subjects being studied and their roles in the setting, and the impact that the observer may have had on the environment.<\/li>\n<li>Reflective information is the observer&#8217;s reflections about the observation being conducted. These reflections are ideas, questions, concerns, and other related thoughts.<\/li>\n<\/ul>\n<p>Fieldnotes often include sketches, diagrams, and other drawings.<\/p>\n<h2>Maps<\/h2>\n<p>Maps are essential tools in geology because they describe the features of earth&#8217;s surface!\u00a0 Geology lab courses expose students to both topographic and geologic maps.\u00a0 Below are a few notes on these.<\/p>\n<h3>Topographic Maps<\/h3>\n<div id=\"attachment_1430\" style=\"width: 410px\" class=\"wp-caption alignright\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-1430\" class=\"wp-image-1430\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/115\/2016\/04\/14222609\/Map.png\" alt=\"A complex map of Yellowstone. There are several natural features on the map, including springs, geysers, and plains.\" width=\"400\" height=\"378\" \/><\/p>\n<p id=\"caption-attachment-1430\" class=\"wp-caption-text\">Figure 1. Map of Yellowstone.<\/p>\n<\/div>\n<p>A <strong>topographic map<\/strong>\u00a0(like the one in figure 1) is one type of map used by geologists. Topographic maps show the three-dimensional shape of the land and features on the surface of the earth. Topographic maps are also used by hikers, planners who make decisions on zoning and construction permits, government agencies involved in land use planning and hazard assessments, and civil engineers. The topographic maps drawn and published by the U. S. Geological Survey portray the grids that are used on deeds to identify the location of real estate, so homeowners and property owners sometimes find it useful to refer to topographic maps of their area.<\/p>\n<p>Topographic maps make use of contour lines to depict elevations above sea level. Each contour line represents a line of constant elevation&#8211; running your finger along a line, or actually going out and walking a line, means that your elevation of above sea level remains constant. Those proficient with &#8220;topo maps&#8221; are able to visualize three dimensional features like mountains, plains, ridges, or valleys simply by looking at the 2-D image.<\/p>\n<p>Why do geologists care about 3-D structures?\u00a0 Earth&#8217;s 3-D surface features are fundamentally a result of some combination of rock type, rock deformation, and\/or erosion!<\/p>\n<p>The topographic map is the starting point for a geologic map.\u00a0 A geologic map is (at its essence) simply a topographic map that has been colored to show the location of different rock types; symbols are added to show structures like rock breaking planes (faults and fractures) and rock bends (folds).<\/p>\n<p>Note On USGS Maps:<br \/>\nStandard United States Geological Survey topographic maps cover a quadrangle. A map quadrangle spans a fraction of a degree of longitude east-to-west and the same fraction of a degree of latitude north-to-south. Because lines of longitude degrees (also called meridians) in the Northern Hemisphere come closer and closer together the nearer they get to the North Pole, whereas lines of latitude degrees remain the same distance apart as they circle the earth, quadrangle maps span less distance east-to-west than they do north-to-south.<\/p>\n<p>Two common quadrangle sizes are 7.5 minutes (1\/8 of a degree), and 15 minutes (1\/4 of a degree).<\/p>\n<div class=\"textbox key-takeaways\">\n<h3>Name, Size, and Latitude-Longitude of a Topographic Map Quadrangle<\/h3>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-1561\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/115\/2016\/05\/10174754\/mapName.gif\" alt=\"A map portion. It reads Juniper Quadrangle, Oregon\u2013Washington. 7.5 minute series (topographic). Below this is the lines of the top right corner of the map. There are markings indicating the east at 119 degrees 00' and the north ad 46 degrees 00'. The corner is labelled Wallula 1:125,000).\" width=\"773\" height=\"228\" \/><\/p>\n<p>&nbsp;<\/p>\n<\/div>\n<div class=\"textbox key-takeaways\">\n<h3>Map Scale, Contour Interval, and Magnetic Declination<\/h3>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-1562\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/115\/2016\/05\/10175824\/mapScale.gif\" alt=\"The scale at the bottom of a map. The bottom edge of the map can be seen. 5\u2019 and 2\u201930\u2019\u2019 are noted on the edge of the map. On the left side of this clip, you can read 360,000 Feet (Oreg.). In the center of the bottom edge it reads Umatilla 1:125,000. The scale is stated to be 1:24,000. There are three scale bars indicating the length on the map that equals a mile, 7000 feet, and 1 kilometer. The contours interval is 20 feet. Datum is mean sea level. Depth curves and sounds in feet; datum is normal pool elevation 340 feet. The approximate man declination, 1962 measures a 20 and a half degree difference between true north and magnetic north. Below this is a short passage that reads as follows: This map complies with National map accuracy standards. For sale by the U.S. Geological Survey, Denver 25, Colorado or Washington 25, D.C. A folder describing topographic maps and symbols is available on request.\" width=\"1124\" height=\"406\" \/><\/p>\n<p>Important information is shown at the bottom of a USGS quadrangle map, including the map scale, the contour interval, and the magnetic declination. The image above is from the bottom of the Juniper 7.5 minute quadrangle. It tells you, among other things:<\/p>\n<ol>\n<li>The map scale. The map scale is listed in terms of the fractional scale as 1:24,000. This means that 1 inch on the map corresponds to 24,000 inches in the real world represented by the map, or 1 cm equals 24,000 cm; in other words, distances on the map have been shrunk by a factor of 24,000 from their real-world size. Beneath the fractional scale, the map scale is also depicted a different way, in bar scales using three different units. One of the bar scales is in miles, one is in units of thousands of feet, and one is in kilometers.<\/li>\n<li>The contour interval, the difference in elevation between adjacent contour lines on the map, is listed below the map scale as 20 feet.<\/li>\n<li>Declination refers to the &#8220;drift&#8221; or change in relative position of geographic (rotation axis) pole with the magnetic pole.\u00a0 These are generally close in terms of location, but they are rarely exactly coincident.<\/li>\n<\/ol>\n<\/div>\n<h4>Constructing a Topographic Profile<\/h4>\n<p>In the diagram below, you see an idealized topo map, with a line drawn on it, from A to A&#8217;.<br \/>\nIt&#8217;s often useful (certainly by geologists but many other users, including hikers and mountain bikers!) to construct a kind of graph that shows the &#8220;ups and downs&#8221; of topography across a line like A-A&#8217;, and called a topographic profile.<br \/>\nAlthough tedious to do by hand (many computer programs can generate these graphs), a topographic profiles is simply a graph showing the various surface elevation changes as one moves from point A to A&#8217;<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-1566\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/115\/2016\/05\/10184643\/tppD.gif\" alt=\"The same map and grid. The lines in the grid have been connected, to show a slope, which resembles the side view of a mountain.\" width=\"600\" height=\"402\" \/><\/p>\n<h5>Step 5<\/h5>\n<p>Here&#8217;s a completed topo profile.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-1567\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/115\/2016\/05\/10184707\/tppE.gif\" alt=\"The same map and grid. The guide lines have been removed, so it is just the map and a representation of the slope.\" width=\"600\" height=\"411\" \/><\/p>\n<p>Notice on the topographic profile constructed above that the peak of the hill is above 520 ft, but below 540 ft. Similarly, the ends of the profile are below 400 ft but above 380. This is consistent with the elevations of those parts of the line of profile on the map.<\/p>\n<p>Note that the vertical scale on the profile is very different from the horizontal scale on the map. In this example, the map covers 0.25 miles horizontally in less distance than the profile covers 100 feet vertically. As a result, the topographic profile is greatly exaggerated vertically. In an actual view of the hill, looking at it from the side, it would not look nearly as steep as it does in the topographic profile that we have constructed.<\/p>\n<p>Comparing the profile to the topographic map notice that the hill is steeper on the west (left) side than on the east (right) side. This is consistent with the contour lines being spaced more closely on the west side of the hill and farther apart on the east side of the hill.\u00a0 Closely spaced contours indicate steep slopes!<\/p>\n<h3>Bathymetric Maps<\/h3>\n<div id=\"attachment_1560\" style=\"width: 310px\" class=\"wp-caption alignright\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-1560\" class=\"wp-image-1560\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/115\/2016\/05\/10174339\/LoihiBathemetric.jpg\" alt=\"Figure 3. Loihi volcano growing on the flank of Kilauea volcano in Hawaii. Black lines in the inset show the land surface above sea level and blue lines show the topography below sea level. Click on the image to view a larger version.\" width=\"300\" height=\"362\" \/><\/p>\n<p id=\"caption-attachment-1560\" class=\"wp-caption-text\">Figure 3. Loihi volcano growing on the flank of Kilauea volcano in Hawaii. Black lines in the inset show the land surface above sea level and blue lines show the topography below sea level. Click on the image to view a larger version.<\/p>\n<\/div>\n<p id=\"x-ck12-YzMyZDNkZTcxMTZjM2Y0YTU5ZjU1ZmJhNjZjODdlYmE.-k5s\">A <strong><span class=\"vocab_term\">bathymetric map<\/span><\/strong> is like a <span class=\"vocab_term\">topographic map<\/span> with the contour lines representing depth below sea level, rather than height above. Numbers are low near sea level and become higher with depth.<\/p>\n<p id=\"x-ck12-ZTViNmIyY2EyZDYxYmUwYWRiNjkxZmI0YTAyYWY5NzY.-10m\">Kilauea is the youngest volcano found above sea level in Hawaii. On the flank of Kilauea is an even younger volcano called Loihi. The bathymetric map pictured in figure 3 shows the form of Loihi.<\/p>\n<h3>Geologic Maps<\/h3>\n<p>A <strong>geologic map<\/strong> is simply a topographic map with added information about rocks and rock features.<br \/>\nThe first thing one notices about a geologic map is that they are quite colorful.\u00a0 Each color represents a particular rock type or rock age-group.\u00a0 Additionally, various symbols are imposed on the map which indicates rock features such as folds (bent or warped rocks) and faults (planar to semi-planar zones of rock breakage).\u00a0 All of these colors and symbols are reviewed in the map key or legend.<\/p>\n<p>A particular color zone on the map represents a rock unit that can be consistently recognized, traced across a landscape, and described, such that in the hands of another geologist these units can be identified and verified.<\/p>\n<div id=\"attachment_1435\" style=\"width: 439px\" class=\"wp-caption alignright\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-1435\" class=\"size-full wp-image-1435\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/115\/2016\/04\/14223303\/geologic.jpg\" alt=\"geologic map of the region around Old Faithful, Yellowstone National Park\" width=\"429\" height=\"500\" \/><\/p>\n<p id=\"caption-attachment-1435\" class=\"wp-caption-text\">Figure 4. A geologic map of the region around Old Faithful, Yellowstone National Park.<\/p>\n<\/div>\n<p>Geologic maps are useful inasmuch as they provide a visual image of key geologic features over a broad area.<br \/>\nThey can be used to generate &#8220;cross sections&#8221; showing the subsurface geology and orientation of rocks units at depth.<br \/>\nWhy is all this useful?<br \/>\nFirstly, because this is the starting point for making interpretations about the geologic history of a region (including what sort of conditions were at the surface during past eras, and also what sort of forces contorted the rocks at depth).\u00a0 Secondly, there are all kinds of <span style=\"float: none;background-color: transparent;color: #373d3f;cursor: text;font-family: 'proxima-nova',sans-serif;font-size: 16px;font-style: normal;font-variant: normal;font-weight: 400;letter-spacing: normal;text-align: left;text-decoration: none;text-indent: 0px\">practical applications, whereby geologic maps are crucial&#8211; such as zoning, civil engineering, groundwater and hazard assessment.<\/span><\/p>\n<p>.<\/p>\n<h4><\/h4>\n<h4>What do we find on a geologic map?<\/h4>\n<p>The legend or key to a geologic map is usually printed on the same page as the map and follows a customary format. The symbol for each rock or sediment unit is shown in a box next to its name and brief description. These symbols are stacked in age sequence from oldest at the bottom to youngest at the top. The geologic era, or period, or epoch&#8211;the geologic age&#8211;is listed for each rock unit in the key. By stacking the units in age sequence from youngest at the top to oldest at the bottom, and identifying which interval of geologic time each unit belongs to, the map reader can quickly see the age of each rock or sediment unit. The map key also contains a listing and explanation of the symbols shown on the map, such as the symbols for different types of faults and folds. See the Table of Geologic Map Symbols\u00a0for pictures and an overview of the map symbols, including strikes and dips, faults, folds, and an overview.<\/p>\n<h4>Table of Geologic Map Symbols<\/h4>\n<table>\n<thead>\n<tr>\n<th colspan=\"3\">Strike and Dip Symbols<\/th>\n<\/tr>\n<tr>\n<td colspan=\"3\"><em>Strike and dip are a way of representing the three-dimensional orientation of a planar surface on a two-dimensional map. The strike is the compass direction of a horizontal line on the plane. All the horizontal lines on a plane are parallel, so they all have the same characteristic compass direction. The dip is the angle at which the plane slopes downhill from the horizontal, at its maximum slope, which is at right angles (90\u00ba) from strike.<\/em><\/td>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<th>Map Symbol<\/th>\n<th>Definition<\/th>\n<th>Explanation of symbol<\/th>\n<\/tr>\n<tr>\n<td align=\"center\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-283 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/781\/2015\/07\/23111500\/SD-tilted.gif\" alt=\"vertical line with a small horizontal line on its right side labeled 38\" width=\"55\" height=\"54\" \/><\/td>\n<td align=\"center\">strike and dip of beds other than horizontal or vertical<\/td>\n<td>\n<ul>\n<li>strike (longer line) is horizontal line on bedding plane<\/li>\n<li>strike parallels nearby contacts between stratified rocks<\/li>\n<li>dip shows which way beds run downhill<\/li>\n<li>dip angle, number at end of dip symbol, is how much beds tilt down from horizontal<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n<tr>\n<td align=\"center\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-284 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/781\/2015\/07\/23111500\/SD-horizontal.gif\" alt=\"circle with a t cross inside\" width=\"55\" height=\"58\" \/><\/td>\n<td align=\"center\">horizontal beds<\/td>\n<td>\n<ul>\n<li>because the bed is horizontal it strikes in all directions<\/li>\n<li>because the bed is horizontal, the dip is 0%<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n<tr>\n<td align=\"center\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-285 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/781\/2015\/07\/23111501\/SD-vertical.gif\" alt=\"vertical line with a small horizontal line crossing the middle\" width=\"57\" height=\"59\" \/><\/td>\n<td align=\"center\">strike and dip of vertical beds<\/td>\n<td>\n<ul>\n<li>strike (longer line) is horizontal line on bedding plane<\/li>\n<li>because the bed dips vertically (has a 90% dip), it dips equally in either direction at right angles to strike, so the dip line is shown extending in both directions<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<table>\n<thead>\n<tr>\n<th colspan=\"5\">Geologic Fault Symbols<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<th style=\"width: 10%;\">Type of Fault<\/th>\n<th style=\"width: 10%;\">Map Symbol<\/th>\n<th style=\"width: 30%;\">Definition<\/th>\n<th style=\"width: 10%;\">Type of Regional Stress<\/th>\n<th style=\"width: 30%;\">Geologic Associations<\/th>\n<\/tr>\n<tr>\n<td align=\"center\">normal<\/td>\n<td align=\"center\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-286 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/781\/2015\/07\/23111501\/Normal.jpg\" alt=\"horizontal line with a U above and D below. U on uplifted side, D on down-dropped side.\" width=\"56\" height=\"75\" \/><\/td>\n<td align=\"center\">hanging wall down, footwall up<\/td>\n<td align=\"center\">tension<\/td>\n<td>\n<ul>\n<li>zones of crustal extension<\/li>\n<li>divergent plate boundaries<\/li>\n<li>edges of horsts and grabens<\/li>\n<li>Basin and Range region<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n<tr>\n<td align=\"center\">detachment<\/td>\n<td align=\"center\">\u00a0<img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-287 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/781\/2015\/07\/23111502\/Detachment.jpg\" alt=\"rectangles on horizontal line (rectangles on upper plate)\" width=\"56\" height=\"75\" \/><\/td>\n<td align=\"center\">low-angle normal fault, footwall\u2014gneiss, hanging wall\u2014shallow-crust rocks<\/td>\n<td align=\"center\">tension<\/td>\n<td>\n<ul>\n<li>boundaries of metamorphic core complexes<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n<tr>\n<td align=\"center\">thrust<\/td>\n<td align=\"center\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-274 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/781\/2015\/07\/23111459\/Convergent.jpg\" alt=\"triangles on horizontal line (triangles on upper plate)\" width=\"56\" height=\"75\" \/><\/td>\n<td align=\"center\">hanging wall up, footwall down<\/td>\n<td align=\"center\">compression<\/td>\n<td>\n<ul>\n<li>zones of crustal compression<\/li>\n<li>convergent plate boundaries<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n<tr>\n<td align=\"center\">reverse<\/td>\n<td align=\"center\">\u00a0<img loading=\"lazy\" decoding=\"async\" class=\"wp-image-274 size-full alignnone\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/781\/2015\/07\/23111459\/Convergent.jpg\" alt=\"triangles on horizontal line (triangles on upper plate)\" width=\"56\" height=\"75\" \/><\/td>\n<td align=\"center\">high-angle (45\u00b0 or more dip) thrust fault<\/td>\n<td align=\"center\">compression<\/td>\n<td>\n<ul>\n<li>zones of crustal compression<\/li>\n<li>convergent plate boundaries<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n<tr>\n<td align=\"center\">strike-slip<\/td>\n<td align=\"center\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-273 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/781\/2015\/07\/23111459\/Transform.jpg\" alt=\"two half-arrows pointing in opposite directions\" width=\"56\" height=\"75\" \/><\/td>\n<td align=\"center\">rocks on either side move horizontally in opposite directions<\/td>\n<td align=\"center\">shear<\/td>\n<td>\n<ul>\n<li>continental margins undergoing oblique (not straight on) plate convergence<\/li>\n<li>transform plate boundaries<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n<tr>\n<td align=\"center\">oblique-slip<\/td>\n<td align=\"center\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-288 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/781\/2015\/07\/23111502\/Oblique.jpg\" alt=\"two half-arrows pointing in opposite directions. U on uplifted side, D on down-dropped side\" width=\"56\" height=\"75\" \/><\/td>\n<td align=\"center\">combines horizontal and vertical motion<\/td>\n<td align=\"center\">combination<\/td>\n<td>\n<ul>\n<li>orogenic mountain belts<\/li>\n<li>continental margins undergoing oblique (not straight on) plate convergence<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<table>\n<thead>\n<tr>\n<th colspan=\"4\">Geologic Fold Symbols<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<th>Type of Fold<\/th>\n<th>Map Symbol<\/th>\n<th>Definition<\/th>\n<th>Appearance of Beds in Map View<\/th>\n<\/tr>\n<tr>\n<td align=\"center\">anticline<\/td>\n<td align=\"center\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-290 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/781\/2015\/07\/23111502\/Anticline.jpg\" alt=\"horizontal line with a vertical line crossing it. There are arrows on both ends of the vertical line pointing away from the horizontal line.\" width=\"56\" height=\"75\" \/><\/td>\n<td align=\"center\">up fold<\/td>\n<td>\n<ul>\n<li>roughly parallel stripes<\/li>\n<li>dip away from center (away from axis)<\/li>\n<li>oldest at center (along axis)<\/li>\n<li>youngest farthest from center<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n<tr>\n<td align=\"center\">plunging anticline<\/td>\n<td align=\"center\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-291 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/781\/2015\/07\/23111502\/PlungingAnticline.jpg\" alt=\"horizontal arrow pointing to the right with a vertical line crossing it. There are arrows on both ends of the vertical line pointing away from the horizontal line.\" width=\"56\" height=\"75\" \/><\/td>\n<td align=\"center\">up fold with tilted axis<\/td>\n<td>\n<ul>\n<li>roughly a U-shaped pattern<\/li>\n<li>plunges in direction U points<\/li>\n<li>oldest at center (along axis)<\/li>\n<li>youngest farthest from center<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n<tr>\n<td align=\"center\">syncline<\/td>\n<td align=\"center\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-292 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/781\/2015\/07\/23111503\/Syncline.jpg\" alt=\"Horizontal line with a vertical line crossing it. There are arrows on the internal ends of the vertical line pointing at the horizontal line.\" width=\"56\" height=\"75\" \/><\/td>\n<td align=\"center\">down fold<\/td>\n<td>\n<ul>\n<li>roughly parallel stripes<\/li>\n<li>dip toward center (toward axis)<\/li>\n<li>oldest farthest from center<\/li>\n<li>youngest at center (along axis)<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n<tr>\n<td align=\"center\">plunging syncline<\/td>\n<td align=\"center\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-293 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/781\/2015\/07\/23111503\/PlungingSyncline.jpg\" alt=\"Horizontal arrow with a vertical line crossing it. There are arrows on the internal ends of the vertical line pointing at the horizontal line.\" width=\"56\" height=\"75\" \/><\/td>\n<td align=\"center\">down fold with tilted axis<\/td>\n<td>\n<ul>\n<li>roughly a U-shaped pattern<\/li>\n<li>plunges in direction U opens<\/li>\n<li>oldest farthest from center<\/li>\n<li>youngest at center (along axis)<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n<tr>\n<td align=\"center\">monocline<\/td>\n<td align=\"center\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-294 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/781\/2015\/07\/23111503\/Monocline.jpg\" alt=\"Horizontal line with a vertical line crossing it. There is an arrow on the top end of the vertical line.\" width=\"56\" height=\"75\" \/><\/td>\n<td align=\"center\">strata tilted in one direction<\/td>\n<td>\n<ul>\n<li>all dip in same direction<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n<tr>\n<td align=\"center\">structural dome<\/td>\n<td align=\"center\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-295 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/781\/2015\/07\/23111503\/StructuralDome.gif\" alt=\"Horizontal arrow pointing to the right and the left with a vertical line crossing it. There are arrows on both ends of the vertical line pointing away from the horizontal line.\" width=\"56\" height=\"75\" \/><\/td>\n<td align=\"center\">upward bulge in layered rocks<\/td>\n<td>\n<ul>\n<li>roughly a bull&#8217;s eye pattern<\/li>\n<li>dip away from center<\/li>\n<li>oldest in center<\/li>\n<li>youngest farthest from center<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n<tr>\n<td align=\"center\">structural basin<\/td>\n<td align=\"center\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-296 size-full\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/781\/2015\/07\/23111504\/StructuralBasin.jpg\" alt=\"Horizontal line with a vertical line crossing it. There are arrows on the internal ends of the vertical line pointing at the horizontal line. There are also arrows on the horizontal line pointing inward at the vertical line.\" width=\"56\" height=\"75\" \/><\/td>\n<td align=\"center\">downward bulge in layered rocks<\/td>\n<td>\n<ul>\n<li>roughly a bull&#8217;s eye pattern<\/li>\n<li>dip toward center<\/li>\n<li>youngest in center<\/li>\n<li>oldest farthest from center<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>The explanations of rock units are often given in a separate pamphlet that accompanies the map. The explanations include descriptions with enough detail for any geologist to be able to recognize the units and learn how their ages were determined.<\/p>\n<p>If included, cross-sections are usually printed on the same page as the geologic map. They are important accompaniments to geologic maps, especially if the map focuses on the geology of the bedrock underneath the soil and loose sediments.<\/p>\n<h4>Geologic Cross-Sections<\/h4>\n<p>A geologic cross-section is a sideways view of a slice of the earth. It shows how the different types of rock are layered or otherwise configured, and it portrays geologic structures beneath the earth&#8217;s surface, such as faults and folds. Geologic cross-sections are constructed on the basis of the geology mapped at the surface combined with an understanding of rocks in terms of physical behavior and three-dimensional structures.<\/p>\n<h3>Summary<\/h3>\n<ul>\n<li>Earth scientists regularly use topographic, bathymetric, and geologic maps.<\/li>\n<li>Topographic maps reveal the shape of a landscape. Elevations indicate height above sea level.<\/li>\n<li>Bathymetric maps are like topographic maps of features found below the water. Elevations indicate depth below sea level.<\/li>\n<li>Geologic maps show rock units and geologic features like faults and folds.<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<h3>Making MODELS as a Means to Do Science!<\/h3>\n<p>A <strong>physical model<\/strong> is a representation of something using objects. It can be three-dimensional, like a globe. It can also be a two-dimensional drawing or diagram. Models are usually smaller and simpler than the real object. They most likely leave out some parts, but contain the important parts. In a good model the parts are made or drawn to scale. Physical models allow us to see, feel and move their parts. This allows us to better understand the real system.<\/p>\n<p>An example of a physical model is a drawing of the layers of Earth (figure 6). A drawing helps us to understand the structure of the planet. Yet there are many differences between a drawing and the real thing. The size of a model is much smaller, for example. A drawing also doesn\u2019t give good idea of how substances move. Arrows showing the direction the material moves can help. A physical model is very useful but it can\u2019t explain the real Earth perfectly.<\/p>\n<div id=\"attachment_1440\" style=\"width: 787px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-1440\" class=\"size-full wp-image-1440\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/115\/2016\/04\/14224536\/Fig_2_5.png\" alt=\"Diagram showing the different layers of the earth. From the outside to the inside they are the crust, moho, upper mantle, lower mantle, D(double prime)-layer, outer core, liquid-solid boundary, and inner core.\" width=\"777\" height=\"415\" \/><\/p>\n<p id=\"caption-attachment-1440\" class=\"wp-caption-text\">Figure 6. Earth\u2019s Center.<\/p>\n<\/div>\n<h3>Ideas as Models<\/h3>\n<div id=\"attachment_1441\" style=\"width: 202px\" class=\"wp-caption alignright\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-1441\" class=\"size-full wp-image-1441\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/115\/2016\/04\/14224643\/collision.jpg\" alt=\"An illustration of a meteor a third of the size of the earth colliding with the planet.\" width=\"192\" height=\"154\" \/><\/p>\n<p id=\"caption-attachment-1441\" class=\"wp-caption-text\">Figure 7. A collision showing a meteor striking Earth.<\/p>\n<\/div>\n<p>Some models are based on an idea that helps scientists explain something. A good idea explains all the known facts. An example is how Earth got its Moon. A Mars-sized planet hit Earth and rocky material broke off of both bodies (figure 7). This material orbited Earth and then came together to form the Moon. This is a model of something that happened billions of years ago. It brings together many facts known from our studies of the Moon&#8217;s surface. It accounts for the chemical makeup of rocks from the Moon, Earth, and meteorites. The physical properties of Earth and Moon figure in as well. Not all known data fits this model, but much does. There is also more information that we simply don\u2019t yet know.<\/p>\n<h3>Models that Use Numbers<\/h3>\n<p>Models may use formulas or equations to describe something. Sometimes math may be the only way to describe it. For example, equations help scientists to explain what happened in the early days of the universe. The universe formed so long ago that math is the only way to describe it. A climate model includes lots of numbers, including temperature readings, ice density, snowfall levels, and humidity. These numbers are put into equations to make a model. The results are used to predict future climate. For example, if there are more clouds, does global temperature go up or down? Models are not perfect because they are simple versions of the real situation. Even so, these models are very useful to scientists. These days, models of complex things are made on computers.<\/p>\n<h2>Geologic Modelling<\/h2>\n<div id=\"attachment_1695\" style=\"width: 410px\" class=\"wp-caption alignright\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-1695\" class=\"wp-image-1695\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/115\/2016\/05\/18204134\/Contour_map_software_screen-e1463604138754.jpg\" alt=\"Screenshot of a structure map generated by Contour map software for an 8500ft deep gas &amp; Oil reservoir in the Erath field, Vermilion Parish, Erath, Louisiana. The left-to-right gap, near the top of the contour map indicates a Fault line. This fault line is between the blue\/green contour lines and the purple\/red\/yellow contour lines. The thin red circular contour line in the middle of the map indicates the top of the oil reservoir. Because gas floats above oil, the thin red contour line marks the gas\/oil contact zone.\" width=\"400\" height=\"483\" \/><\/p>\n<p id=\"caption-attachment-1695\" class=\"wp-caption-text\">Figure 8. Geological mapping software displaying a screenshot of a structure map generated for an 8500ft deep gas &amp; Oil reservoir in the Erath field, Vermilion Parish, Erath, Louisiana. The left-to-right gap, near the top of the contour map indicates a Fault line. This fault line is between the blue\/green contour lines and the purple\/red\/yellow contour lines. The thin red circular contour line in the middle of the map indicates the top of the oil reservoir. Because gas floats above oil, the thin red contour line marks the gas\/oil contact zone.<\/p>\n<\/div>\n<p><strong>Geologic modelling<\/strong>, or <strong>Geomodelling<\/strong>, is the applied science of creating computerized representations of portions of the Earth&#8217;s crust based on geophysical and geological observations made on and below the Earth surface. A Geomodel is the numerical equivalent of a three-dimensional geological map complemented by a description of physical quantities in the domain of interest. Geomodelling is related to the concept of Shared Earth Model; which is a multidisciplinary, interoperable and updatable knowledge base about the subsurface.<\/p>\n<div id=\"attachment_1698\" style=\"width: 410px\" class=\"wp-caption alignright\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-1698\" class=\"wp-image-1698\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/115\/2016\/05\/18210402\/MODFLOW_3D_grid.png\" alt=\"Three-dimensional finite difference grid used in MODFLOW.\" width=\"400\" height=\"284\" \/><\/p>\n<p id=\"caption-attachment-1698\" class=\"wp-caption-text\">Figure 9. A 3D finite difference grid used in MODFLOW for simulating groundwater flow in an aquifer.<\/p>\n<\/div>\n<p>&nbsp;<\/p>\n<h4><\/h4>\n<p>&nbsp;<\/p>\n<h4><\/h4>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<div id=\"attachment_1699\" style=\"width: 791px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-1699\" class=\"size-full wp-image-1699\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/115\/2016\/05\/18210540\/781px-Gravity_Highs.jpg\" alt=\"Gravity Highs over the Mardin Uplift\" width=\"781\" height=\"600\" \/><\/p>\n<p id=\"caption-attachment-1699\" class=\"wp-caption-text\">Figure 10. Gravity Highs<\/p>\n<\/div>\n<ul>\n<li><\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<ul>\n<li><\/li>\n<\/ul>\n<p>:<\/p>\n<ul>\n<li><\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<\/div>\n<\/div>\n\n\t\t\t <section class=\"citations-section\" role=\"contentinfo\">\n\t\t\t <h3>Candela Citations<\/h3>\n\t\t\t\t\t <div>\n\t\t\t\t\t\t <div id=\"citation-list-1400\">\n\t\t\t\t\t\t\t <div class=\"licensing\"><div class=\"license-attribution-dropdown-subheading\">CC licensed content, Original<\/div><ul class=\"citation-list\"><li>Introduction to Scientific Tools. <strong>Authored by<\/strong>: Kimberly Schulte and Lumen Learning. <strong>Provided by<\/strong>: Lumen Learning. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY: Attribution<\/a><\/em><\/li><li>Revision, Adaptation, and Original Content. <strong>Authored by<\/strong>: Kimberly Schulte and Lumen Learning. <strong>Provided by<\/strong>: Lumen Learning. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/\">CC BY-SA: Attribution-ShareAlike<\/a><\/em><\/li><\/ul><div class=\"license-attribution-dropdown-subheading\">CC licensed content, Shared previously<\/div><ul class=\"citation-list\"><li>Geological compass. <strong>Provided by<\/strong>: Wikipedia. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"https:\/\/en.wikipedia.org\/wiki\/Geological_compass\">https:\/\/en.wikipedia.org\/wiki\/Geological_compass<\/a>. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/\">CC BY-SA: Attribution-ShareAlike<\/a><\/em><\/li><li>Geologist&#039;s hammer. <strong>Provided by<\/strong>: Wikipedia. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"https:\/\/en.wikipedia.org\/wiki\/Geologist%27s_hammer\">https:\/\/en.wikipedia.org\/wiki\/Geologist%27s_hammer<\/a>. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/\">CC BY-SA: Attribution-ShareAlike<\/a><\/em><\/li><li>Loupe. <strong>Provided by<\/strong>: Wikipedia. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"https:\/\/en.wikipedia.org\/wiki\/Loupe\">https:\/\/en.wikipedia.org\/wiki\/Loupe<\/a>. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/\">CC BY-SA: Attribution-ShareAlike<\/a><\/em><\/li><li>Fieldnotes. <strong>Provided by<\/strong>: Wikipedia. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"https:\/\/en.wikipedia.org\/wiki\/Fieldnotes\">https:\/\/en.wikipedia.org\/wiki\/Fieldnotes<\/a>. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/\">CC BY-SA: Attribution-ShareAlike<\/a><\/em><\/li><li>2.5: Maps. <strong>Provided by<\/strong>: CK-12. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"http:\/\/www.ck12.org\/book\/CK-12-Earth-Science-Concepts-For-High-School\/section\/2.5\/\">http:\/\/www.ck12.org\/book\/CK-12-Earth-Science-Concepts-For-High-School\/section\/2.5\/<\/a>. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC: Attribution-NonCommercial<\/a><\/em><\/li><li>Basics -- Topographic &amp; Geologic Maps. <strong>Authored by<\/strong>: Ralph L. Dawes, Ph.D. and Cheryl D. Dawes. <strong>Provided by<\/strong>: Wenatchee Valley College. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"https:\/\/commons.wvc.edu\/rdawes\/G101OCL\/Basics\/mapkey.html\">https:\/\/commons.wvc.edu\/rdawes\/G101OCL\/Basics\/mapkey.html<\/a>. <strong>Project<\/strong>: Geology 101 - Introduction to Physical Geology. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY: Attribution<\/a><\/em><\/li><li>2.4: Location and Direction. <strong>Provided by<\/strong>: CK-12. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"http:\/\/www.ck12.org\/book\/CK-12-Earth-Science-Concepts-For-High-School\/section\/2.4\/\">http:\/\/www.ck12.org\/book\/CK-12-Earth-Science-Concepts-For-High-School\/section\/2.4\/<\/a>. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC: Attribution-NonCommercial<\/a><\/em><\/li><li>Old Faithful Rainbow. <strong>Authored by<\/strong>: Flicka. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Old_Faithful_Rainbow.jpg\">https:\/\/commons.wikimedia.org\/wiki\/File:Old_Faithful_Rainbow.jpg<\/a>. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/\">CC BY-SA: Attribution-ShareAlike<\/a><\/em><\/li><li>1.1: The Nature of Science. <strong>Provided by<\/strong>: CK-12. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"http:\/\/www.ck12.org\/book\/CK-12-Earth-Science-For-Middle-School\/section\/1.1\/\">http:\/\/www.ck12.org\/book\/CK-12-Earth-Science-For-Middle-School\/section\/1.1\/<\/a>. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC: Attribution-NonCommercial<\/a><\/em><\/li><li>Geologic modelling. <strong>Provided by<\/strong>: Wikipedia. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"https:\/\/en.wikipedia.org\/wiki\/Geologic_modelling\">https:\/\/en.wikipedia.org\/wiki\/Geologic_modelling<\/a>. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/\">CC BY-SA: Attribution-ShareAlike<\/a><\/em><\/li><\/ul><div class=\"license-attribution-dropdown-subheading\">All rights reserved content<\/div><ul class=\"citation-list\"><li>UCLA&#039;s Augmented Reality Sandbox. <strong>Authored by<\/strong>: UCLA. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"https:\/\/youtu.be\/CE1B7tdGCw0\">https:\/\/youtu.be\/CE1B7tdGCw0<\/a>. <strong>License<\/strong>: <em>All Rights Reserved<\/em>. <strong>License Terms<\/strong>: Standard YouTube License<\/li><li>Latitude and Longitude. <strong>Authored by<\/strong>: Andy Jensen. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"https:\/\/youtu.be\/swKBi6hHHMA\">https:\/\/youtu.be\/swKBi6hHHMA<\/a>. <strong>License<\/strong>: <em>All Rights Reserved<\/em>. <strong>License Terms<\/strong>: Standard YouTube License<\/li><\/ul><div class=\"license-attribution-dropdown-subheading\">Public domain content<\/div><ul class=\"citation-list\"><li>Loihi Bathemetric. <strong>Authored by<\/strong>: NOAA. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"https:\/\/commons.wikimedia.org\/wiki\/File:LoihiBathemetric.jpg\">https:\/\/commons.wikimedia.org\/wiki\/File:LoihiBathemetric.jpg<\/a>. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/about\/pdm\">Public Domain: No Known Copyright<\/a><\/em><\/li><\/ul><\/div>\n\t\t\t\t\t\t <\/div>\n\t\t\t\t\t <\/div>\n\t\t\t <\/section>","protected":false},"author":17,"menu_order":4,"template":"","meta":{"_candela_citation":"[{\"type\":\"original\",\"description\":\"Introduction to Scientific 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