What events lead to the formation of Warm Up 10/18/16 What events lead to the formation of sedimentary rocks?

What is a Rock? Naturally occurring solid aggregate of minerals Earth’s outer solid layer, the lithosphere, is made of rock Three types: Igneous, Sedimentary, and Metamorphic

Types of Rocks Igneous– form from solidification of molten (liquid) rock material. Most common rock in crust. Sedimentary– form from compaction and cementation of sediments. Common on surface. Metamorphic– form from re-crystallization of existing rock material. 3

How is Sedimentary Rock Formed? Weathering Erosion Deposition Burial Lithification – sediments compact under pressure and gradually become solid rock

3 Main Classes of Sedimentary Rocks Clastic Sedimentary – formed from clastic sediments Chemical Sedimentary – formed from minerals precipitated from water Organic – formed from the remains of once- living things

Sedimentary Rocks Clastic Sedimentary- sedimentary rocks formed from layers Conglomerate

Clastic Sedimentary Clast refers to a fragment of rock that was broken from a larger rock Clastic rocks are composed of these clasts. Clastic metamorphic rocks include breccias formed in faults Clastic igneous rocks include some volcanic rocks – the ones broken by flow, injections or explosive disruption of lavas. Breccia= clastic sedimentary rock that are composed of large angular fragments.

clay silt sand gravel conglomerate sandstone siltstone shale sediments sedimentary rocks conglomerate sandstone siltstone shale

Breccia Rock Rock composed of broken fragments of minerals or rock cemented together by a fine-grained matrix Formed by debris flows, avalanches, mud flows

Shale Fine-grained, clastic sedimentary rock composed of flakes of clay minerals and other tiny fragments. Formed during the compaction part of the rock cycle.

sorting Sandstone Chapter 6 Sedimentary rocks Detrital sedimentary rocks Sandstone sorting degree of similarity in particle size Very poorly-sorted Very well-sorted moderately sorted

Chemical Sedimentary- sedimentary rocks formed from mineral pools after water has evaporated Halite Hematite

Salinas Grandes, Argentina Evaporites

Organic Sedimentary- sedimentary rocks formed from the remains of once- living things. Coal

Limestone Most abundant organic sedimentary is limestone. Shells of marine organisms (coral reefs) settle to bottom of ocean forming thick layers of carbonate sediment. Through burial and lithification, it is formed into limestone.

Discussion Why do chemical sedimentary rocks form primarily in areas that have high rates of evaporation?

Talk It Over What are some of the commercial values of sedimentary rocks?

Think It Over In Your Group What are the four main agents of erosion? Discuss how each of these factors transport rock fragments to new locations.

Glacier

Moving Water

Wind

Gravity