Lecture 8 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 Webpage for course (daytime) Webpage for course (nighttime)

Three types of rocks: - Igneous -Sedimentary - Metamorphic

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

Example, coal

Nonclastic Another example, rock salt

Clastic Classification depends on grain size Size (mm)particle name > <0.0039

Clastic Classification depends on grain size Size (mm)particle namerock name >256 boulder cobble 4-64pebble 2-4granule sand silt <0.0039clay

Clastic Classification depends on grain size Size (mm)particle namerock name >256 boulder cobble 4-64pebble 2-4granule sandsandstone silt <0.0039clay

Clastic Classification depends on grain size Size (mm)particle namerock name >256 boulder cobbleconglomerate 4-64pebbleor breccia 2-4granule sandsandstone siltsiltstone <0.0039clayshale

Why the distinction conglomerate and breccia?

Conglomerate means slow, breccia means sudden

Nonclastic Chemical Biogenic Coal Coquina Chalk Diatomite

Diatoms

Nonclastic Chemical Rock Salt Chert Limestone Dolomite Biogenic Coal Coquina Chalk Diatomite

Coal as Energy