30 November 2011 OBJECTIVE: Describe the origin of sedimentary rock. INTRO Have You ever tried to build a sand castle at the beach? Did you ever wonder where the sand came from?

Sedimentary Rock

Sedimentary rock Strata Forms when sediments are compacted into a rock Most created at the bottom of oceans and lakes Can contain fossils of plants and animals Layers of rock

Sedimentary Rocks 3 Types: – Clastic Sedimentary Rock Made of fragments of rocks cemented together by minerals Course-grained (rough) Medium-grained Fine-grained (smooth) Can easily record ancient animal footprints, wave ripples, and even raindrops!

Sedimentary Rocks Chemical sedimentary rock Forms from solutions of dissolved minerals and water Dissolved material eventually crystallizes and forms minerals in the sedimentary rock Example: – Halite (salt) is found in sedimentary rocks

Sedimentary Rocks Organic sedimentary rock Forms from the remains of plants and animals Example: – Limestone forms when coral becomes compacted and cemented – Coal forms from partially decomposed plants buried deep underneath sediments

Sedimentary Rock Summary: – How do sedimentary rocks form? – Describe the three types of sedimentary rock.

30 November 2011 OBJECTIVE: Describe the origin of sedimentary rock. INTRO Why do you think raindrop impressions are more likely to be preserved in fine-grained sedimentary rock rather than in course-grained sedimentary rock?