30 November 2011

OBJECTIVE: Describe the origin of sedimentary rock.

INTROHave You ever tried to build a sand castle at the beach? Did you ever wonder where the sand came from?

Sedimentary Rock

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?