Rocks and roles in Earth's history


Sedimentary rock is a type of rock that is formed by the deposition of material at the Earth's surface and within bodies of water. Example; limestone, breccia, chert, oil shale, coal, and rock salt are a few types of sedimentary rocks.

Metamorphic rock is a rock that was once one form of rock but has changed to another under the influence of heat, pressure, or some other agent without passing through a liquid phase. Example; marble and slate are a type of metamorphic rock.

Igneous rock is a rock formed through the cooling and solidification of magma or lava. Example; basalt, gabbro, granite, and scoria are just a few types of igneous rock.

Stratification is a system or formation of layers, classes, or categories. It is used to describe a particular way of arranging seeds while planting, as well as the geological layers of rocks.

stratification in a rock

The age of land forms can be estimated by studying the number and thickness of rock layers. If the rock is thicker or has more layers, you can tell it is older because more sediment has formed into more layers over time.

the rock cycle

Sedimentary rocks are formed particle by particle and bed by bed, and the layers are piled one on top of the other. Therefore, in any sequence of layered rocks, a given bed must be older than any bed on top of it.

Several ways living organisms have shaped land forms are that living organisms die and their shell or skeleton create/build up layers. They dig holes in the ground allowing water to run into the ground. So on and so forth.