* Surface vs. Total Crust: Sedimentary rocks are primarily found at the surface, forming layers on top of other rock types. The vast majority of the Earth's crust is actually made up of igneous and metamorphic rocks, which form deep within the Earth.
* Estimates Vary: There's no exact percentage as estimates vary depending on the data used and methods employed. Some sources estimate that sedimentary rocks make up around 5% of the Earth's total crust, while others may suggest a slightly higher percentage.
Key Points:
* Sedimentary rocks are important for understanding Earth's history: They contain fossils and other clues about past environments and life.
* Igneous and metamorphic rocks dominate the crust: These rocks make up the bulk of the continental and oceanic plates.
So, while sedimentary rocks are important for our understanding of Earth's history and play a crucial role in our lives, they only make up a small fraction of the Earth's total crust.
