Sedimentary Rock Forms at Earth’s Surface
In elementary school, kids learn that there are three main kinds of rocks (ig, met, sed).
After the chapter on igneous rocks, you may have noticed that this book tackled weathering, erosion, soils, and mass wasting ALL before we got to the other primary rock types (sedimentary and metamorphic)! Why?
Well the answer is really that all those processes (weathering, erosion, mass wasting) are things that happen at earth’s surface.
This is the realm of sedimentary rocks.
Sedimentary rocks do NOT form in the deep earth, where magma (igneous rock precursor) and/or metamorphism occur.
Since metamorphic rocks require a starting material– either igneous or sedimentary (or even metamorphic)– we have also waited to discuss the associated processes.
Surface Environments
It is this aspect, i.e. the formation at earth’s surface, that makes sedimentary rocks so powerful.
They allow us to peer into the past and envision what the earth was like when they were forming!
below, a diagram of just some of the many different kinds of environments in which sedimentary rocks might form.
It’s hardly a matter of “on land” (i.e. terrestrial) or in the ocean (i.e. marine),,
There are numerous different kinds of terrestrial environments and marine environments… and EACH will generate specific attributes within sedimentary rocks that form there!
