Sedimentary Rocks Made from Sediments!!

AIM: What are the characteristics of sedimentary rocks? Sedimentary rocks are formed from the accumulation and lithification of sediments Sedimentary rocks are formed from the accumulation and lithification of sediments

Sed Rocks There are 3 types of sedimentary rocks: There are 3 types of sedimentary rocks: –Clastic sedimentary rocks are formed from clay, sand, and gravel (fragments) –Crystalline sedimentary rocks are formed from mineral grains and crystals that precipitate out of solution by evaporation or chemical action –Bioclastic or Organic rocks are formed from the remains of plants and animals

Clastic Rocks Clastic Rocks – the particles consist of weathered existing rocks. Clastic Rocks – the particles consist of weathered existing rocks. Particle sizes vary Particle sizes vary

Clastic Sed Rocks Large accumulations of clastic sediments exist where rivers meet still bodies of water Large accumulations of clastic sediments exist where rivers meet still bodies of water Large accumulations Large accumulations

Clastic Sed Rocks Clastic rocks are lithified by compaction and cementation Clastic rocks are lithified by compaction and cementationlithifiedcompaction cementationlithifiedcompaction cementation Compaction occurs when the weight of overlying sediments compresses the material and squishes out most of the water Compaction occurs when the weight of overlying sediments compresses the material and squishes out most of the water Compaction Cementation occurs when dissolved minerals precipitate in the pores between the particles and glue them together. Ex: silica, calcite, hematite Cementation occurs when dissolved minerals precipitate in the pores between the particles and glue them together. Ex: silica, calcite, hematite hematite

Crystalline Sed Rocks Crystalline Rocks – the minerals dissolved in solution are precipitated from water by evaporation or chemical action. Crystalline Rocks – the minerals dissolved in solution are precipitated from water by evaporation or chemical action.evaporation

Bioclastic Sed Rocks Bioclastic or Organic rocks are formed from accumulations of remains of living things. YES, rocks made of dead stuff Bioclastic or Organic rocks are formed from accumulations of remains of living things. YES, rocks made of dead stuffdead stuffdead stuff

Sed Rocks – Secondary Features Secondary Sedimentary Features: see these in a rock and it’s probably sedimentary. Secondary Sedimentary Features: see these in a rock and it’s probably sedimentary. Stratification – the arrangement of sedimentary rock in visible layers that may separate easily Stratification – the arrangement of sedimentary rock in visible layers that may separate easily

Sed Rocks Secondary Features Fossils – the remains, impressions, or any other evidence of the existence of life preserved in the rock Fossils – the remains, impressions, or any other evidence of the existence of life preserved in the rock

Sed Rocks Secondary Structures Ripple Marks – seen on the surface of a bed of sandstone formed from wave action on the sand sediment before lithification Ripple Marks – seen on the surface of a bed of sandstone formed from wave action on the sand sediment before lithification

Sed Rocks Secondary Structures Mud Cracks – these develop when deposits of wet clay dry out and crack. Cracks often fill with different material Mud Cracks – these develop when deposits of wet clay dry out and crack. Cracks often fill with different material