Sedimentary Rocks

Sedimentary Rocks Related word = “sediment” Sediment - pieces of solid material that have been deposited on earth’s surface by water, wind, ice, gravity or chemical precipitation

Sedimentary Rocks Related word = “sediment” Sediment - pieces of solid material that have been deposited on earth’s surface by water, wind, ice, gravity or chemical precipitation

Weathering a set of physical and chemical processes that break rock into smaller pieces Chemical weathering - When minerals in a rock are dissolved and the rock is changed chemically Physical weathering - Minerals remain unchanged Simply break into small pieces

Clastic Sediments Produced by weathering

What is Sand?

Erosion and Transport The removal and movement of surface materials from one location to another Carried by wind, water, ice and gravity Materials usually move downhill

Erosion and Transport

Deposition When materials are laid down on the ground or sink to the bottom of bodies of water When transport stops, materials are deposited Generally, largest particles settle out first and produce sorted layers Glacier and landslide deposits not sorted

Burial When materials are deposited in basins, other sediments are deposited on top if them. This leads to the layered appearance that some sedimentary rocks exhibit

Lithification Litho?

Compaction  Cementation  Lithification Litho? Lithification - the physical and chemical processes that transform sediments into sedimentary rocks Compaction  Cementation  Lithification

Lithification Compaction? (Similar words?) Compaction - clasts (?) are squeezed together. Water is squeezed out.

Lithification Cementation? (Similar words?) Cementation - mineral growth in spaces between clasts cements clasts together Two methods:

Features of Sedimentary Rocks Bedding - visible horizontal layers in the rock Beds can be millimeters thick or meters thick Type of bedding depends upon the method of transport. Size of grains depend on many factors

Graded Bedding Particle size is bigger and coarser at the bottom of the beds Underwater landslides, fast-moving streams

Cross-Bedding Formed as inclined layers of sediment move forward across a horizontal surface Sand dunes, beaches, lake edges

Cross-Bedding Formed as inclined layers of sediment move forward across a horizontal surface Sand dunes, beaches, lake edges

Evidence of Past Life Fossils - preserved remains, impressions or any other evidence of once-living organisms (Why not in igneous?)

Fossils and Sedimentary Rocks Fossils can help ID the rocks, and vice-versa! Types of fossils found give a clue about the rock’s origin- fossils of marine animals indicate ……

Fossils and Sedimentary Rocks Fossils can help ID the rocks, and vice-versa! Types of fossils found give a clue about the rock’s origin- fossils of marine animals indicate …… The rock formed from sediments deposited near (or in) the sea.

Classifying Sedimentary Rocks

Classifying Sedimentary Rocks

Clastic Sedimentary Rocks Coarse-Grained Clastics Conglomerate Breccia

Clastic Sedimentary Rocks Grain Shape - Influenced by: Distance of transport - The further it travels, the rounder it becomes Length of time of transport- The longer it’s affected by water, wind or ice, the rounder it becomes

Clastic Sedimentary Rocks Medium-Grained Clastics - (Sandstone) sometimes contain oil, natural gas and groundwater Porosity: percentage of open space between grains

Clastic Sedimentary Rocks Fine-grained Clastics (Shale) Has low porosity that hinders movement of oil, water and natural gas

Classifying Sedimentary Rocks

Chemical Sedimentary Rocks Formed from the evaporation of saturated liquids Called evaporites

Chemical Sedimentary Rocks

Classifying Sedimentary Rocks

Organic Sedimentary Rocks Biogenic - (bio = ?; genic = ?)

Organic Sedimentary Rocks Biogenic - (bio = ?; genic = ?) Formed from the remains of once-living things - limestone Organisms use calcium carbonate in their shells and skeletons When they die, they sink to the bottom. Calcium carbonate precipitates into the water the cements the grains of carbonate sediment.

Organic Sedimentary Rocks

Organic Sedimentary Rocks Biogenic - (bio = ?; genic = ?) Formed from the remains of once-living plants - coal Plants in swamps and coastal areas die are buried and compressed. Lithified into coal Why is it called a Fossil fuel?

Identifying Sedimentary Rocks

Identifying Sedimentary Rocks

Identifying Sedimentary Rocks

Identifying Sedimentary Rocks