230 likes | 331 Views
All the rivers run to the sea, yet the sea is not full: unto the place from whence the rivers come, thither they return again. - Ecclesiastes 1:7 Sedimentary Rocks. Lecture 8. Webpage for course (daytime). Webpage for course (nighttime).
E N D
All the rivers run to the sea, yet the sea is not full: unto the place from whence the rivers come, thither they return again. - Ecclesiastes 1:7Sedimentary Rocks Lecture 8 Webpage for course (daytime) Webpage for course (nighttime)
Sedimentary rocks are important because Form and are common at earth’s surface Preserve the history of Life (contain fossils)
Sedimentary rocks are important because Form and are common at earth’s surface Preserve the history of Life (contain fossils) Show past environments, climates Provide a geologic record of past history Major sources of energy – oil, gas, coal
General History of a Sedimentary Rock WEATHERING TRANSPORTATION DECOMPOSITION DEPOSITION LITHIFICATION
Mechanisms of Transportation and Deposition Water - streams, rivers, etc., freshwater and marine Wind Gravity – downslope movement Ice – glaciers Some sedimentary rocks form of atoms dissolved in water and precipitated elsewhere
Classification of sedimentary rocks Clastic (Detrital in your book) Nonclastic
Nonclastic Example, coal
Nonclastic Another example, rock salt
Clastic Classification depends on grain size Size (mm) particle name >256 64-256 4-64 2-4 .0625-2 .0039-.0625 <0.0039
Clastic Classification depends on grain size Size (mm) particle name rock name >256 boulder 64-256 cobble 4-64 pebble 2-4 granule .0625-2 sand .0039-.0625 silt <0.0039 clay
Clastic Classification depends on grain size Size (mm) particle name rock name >256 boulder 64-256 cobble 4-64 pebble 2-4 granule .0625-2 sand sandstone .0039-.0625 silt <0.0039 clay
Clastic Classification depends on grain size Size (mm) particle name rock name >256 boulder 64-256 cobble conglomerate 4-64 pebble orbreccia 2-4 granule .0625-2 sand sandstone .0039-.0625 silt siltstone <0.0039 clay shale
Biogenic Coal Coquina Chalk Diatomite Nonclastic Chemical
Biogenic Coal Coquina Chalk Diatomite Nonclastic Chemical Rock Salt Chert Limestone Dolomite