3.3 Sedimentary rocks form from earlier

rocks

Classifying Rocks

3 rock typesSedimentaryIgneousMetamorphic

SedimentRock fragments, minerals, or plant and animal remains that settle out of water or air

Sedimentary Rocks

“that which has settled”

Formed from sedimentsSediments=rocks exposed to weather that

have been broken down into very small pieces Formation depends on weathering/erosion

Sediments packed into layers

Cement together over time

Sedimentary

Sediments change into Rock by

PressureCemented together by new minerals to form rock

CoalSedimentary rock formed from remains of plants, bark roots, and other plant material that is buried and under pressure

Contains NO minerals

Conglomerate Sedimentary rock with pieces of shells, rocks, minerals or other products that are larger than 2 mm cemented together with minerals.

LimestoneSedimentary rock made of shells and skeletons of ocean organisms.

Over time the individual shells are no longer visible and become limestone

Sedimentary Rock and WindWater movement: Larger sediment drops before smaller sediment

Wind Direction : Cross-beds, Ripples, Mud Cracks

ChallengeRefer to book… What is the difference between compaction and

cementation?Compaction occurs when sediment is squeezed

together by the weight of other sediment above it, and cementation occurs when sediment is cemented together by dissolved minerals.

How do chemical and biochemical sedimentary rocks form?Chemical sedimentary rocks form when minerals

crystallize out of solution in water, and biochemical sedimentary rocks form from the action of organisms in water.