Section 2: Types of Sedimentary Rocks Sedimentary rocks are classified by their mode of formation. K What I Know W What I Want to Find Out L What I Learned

Essential Questions How can the different types of clastic sedimentary rocks be described? How do chemical sedimentary rocks form? What are biochemical sedimentary rocks? Types of Sedimentary Rocks Copyright © McGraw-Hill Education

Vocabulary Review New saturated clastic sedimentary rock clastic porosity evaporite Types of Sedimentary Rocks Copyright © McGraw-Hill Education

Clastic Sedimentary Rocks The most common sedimentary rocks, clastic sedimentary rocks, are formed from the abundant deposits of loose sediments that accumulate on Earth’s surface. Clastic refers to rock and mineral fragments produced by weathering and erosion. These rocks are further classified according to the sizes of their particles. Copyright © McGraw-Hill Education Types of Sedimentary Rocks

Clastic Sedimentary Rocks Coarse-grained rocks Sedimentary rocks consisting of gravel-sized rock and mineral fragments are classified as coarse-grained rocks. Types of Sedimentary Rocks Copyright © McGraw-Hill Education

Clastic Sedimentary Rocks Coarse-grained rocks Conglomerates have rounded, gravel-sized particles. Breccias are composed of angular, gravel-sized particles. Types of Sedimentary Rocks Copyright © McGraw-Hill Education

Add link to Animation from p. 142 here. Classification of Sedimentary Rocks Concepts In Motion FPO Add link to Animation from p. 142 here. Types of Sedimentary Rocks Copyright © McGraw-Hill Education

Clastic Sedimentary Rocks Medium-grained rocks Sedimentary rocks that contain sand-sized rock and mineral fragments are classified as medium-grained clastic rocks. Porosity is the percentage of open spaces between grains in a material, such as rock. Types of Sedimentary Rocks Copyright © McGraw-Hill Education

Clastic Sedimentary Rocks Medium-grained rocks When open spaces between grains in a rock are connected to one another, fluids can move through porous rock such as sandstone. Sandstone layers can be valuable as underground reservoirs of oil, natural gas, and groundwater. Types of Sedimentary Rocks Copyright © McGraw-Hill Education

Clastic Sedimentary Rocks Fine-grained rocks Sedimentary rocks consisting of silt- and clay-sized particles are called fine- grained rocks. Fine-grained sedimentary rock has low porosity and often forms barriers that hinder the movement of groundwater and oil. Types of Sedimentary Rocks Copyright © McGraw-Hill Education

Chemical and Biochemical Sedimentary Rocks When the concentration of dissolved minerals in a body of water reaches saturation, crystals can precipitate out of solution and settle to the bottom. The resulting layers of chemical sedimentary rocks are called evaporites. Types of Sedimentary Rocks Copyright © McGraw-Hill Education

Chemical and Biochemical Sedimentary Rocks The constant evaporation from a body of salt water results in precipitation of large amounts of salts. Types of Sedimentary Rocks Copyright © McGraw-Hill Education

Chemical and Biochemical Sedimentary Rocks Biochemical sedimentary rocks are formed from the remains of once-living organisms. The most abundant of this type of rock is limestone, which is composed primarily of calcite. Types of Sedimentary Rocks Copyright © McGraw-Hill Education

Chemical and Biochemical Sedimentary Rocks After the death of organisms that used calcium carbonate to make their shells, the shells settle to the bottom of the ocean and can form thick layers of carbonate sediment. During burial and lithification of the carbonate sediment formed from the shells of once-living organisms, calcium carbonate precipitates out of the water, crystallizes between the grains of carbonate sediment, and forms limestone. Types of Sedimentary Rocks Copyright © McGraw-Hill Education

Review Essential Questions Vocabulary How can the different types of clastic sedimentary rocks be described? How do chemical sedimentary rocks form? What are biochemical sedimentary rocks? Vocabulary clastic sedimentary rock clastic porosity evaporite Types of Sedimentary Rocks Copyright © McGraw-Hill Education