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Sedimentary Rocks Rocks. Schwichtenberg. Sedimentary Rocks. Pieces of solid material that have been broken down over time by wind, water, gravity, and other natural processes Sediments get cemented together – depends on weathering & erosion. How Are Sedimentary Rocks Classified?.
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Sedimentary Rocks Rocks Schwichtenberg
Sedimentary Rocks • Pieces of solid material that have been broken down over time by wind, water, gravity, and other natural processes • Sediments get cemented together – depends on weathering & erosion
How Are Sedimentary Rocks Classified? • Based on how they were formed
Three Main Groups of Sedimentary Rocks 1. Clastic (Detrital) Sedimentary Rock • Most common type of sedimentary rock • Clasts Present • Formed from loose sediment deposits on earth’s surface
Three Main Groups of Sedimentary Rocks 2. Chemical Sedimentary Rock • Rocks formed by chemical weathering • Clasts not present • Change from one form to another • Change Mineral Content
Three Main Groups of Sedimentary Rocks 3. Organic Sedimentary Rock • Rocks formed from once living things • Organic Material – contain carbon
How are Sedimentary Rocks Classified? Clastic vs. Chemical clasts presentclasts not present particles visible particles not visible
Clastic (Detrital)Course Conglomerate Breccia
Two Types of Weathering • Chemical Weathering • Occurs when minerals within a rock are dissolved or become chemically changed • Physical Weathering • Minerals that are chemically unchanged break along fractures or grain boundaries • Physical properties are changed
Results of Weathering • Clastic Sediments • Rock & Mineral Fragments
Boulder Pebble Cobble Sand Clay Silt
LARGEST SMALLEST!
Erosion • Transport & Movement of sediments Jebel Kharaz, Jordan
Four Main Methods of Erosion • Wind • Water • Ice/Glaciers • Gravity
Formation of Sedimentary Rocks 1. Deposition • When sediments are laid down on surfaces or sink to bottom of bodies of water • Sediments are settling out
Formation of Sedimentary Rocks 2. Burial • Repeated deposition & layering over time • Banding may occur
Formation of Sedimentary Rocks Lithification 3. Compaction 4. Cementation
Lithification 3. Compaction - Squeezing out of fluids from intense pressure - Causes a physical change
Lithification 4. Cementation - Sediments come together to form a solid rock HOW? Cementing materials carried in solution by water through pore spaces and between particles. Have compaction and temperatures rise. Causes a chemical & mineral change and particles join
Sequence How Sedimentary Rock is Formed From Clastic Sediments
Sequence How Sedimentary Rock is Formed From Clastic Sediments