430 likes | 1.24k Views
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?.
E N D
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