Sedimentary Rocks http://www.youtube.com/watch?v=Etu9BWbuDlY

Formation Compacted and Cemented sediments from pre-existing rocks or organisms

Three Types Clastic - Composed of sediments (rock particles -silt, sand, pebbles, etc) Size of sediments tells a lot about the depositional environment

Intertidal and/or rivers Sandstone

Shorelines/silt to sandy marine environments Sandstone Siltstone

Middle of ocean basins Shales

2. Non-Clastic Sedimentary Rocks a. Crystalline - Minerals left behind from the evaporation of water (evaporites) or water sample if full with dissolved minerals and they “fall” out of water and create a rock (precipitates) Dolostone

2. Non-Clastic Sedimentary Rocks b. Bioclastic - Cemented organic remains (shell fragments, decayed plants) Swamps, bogs buried plant material with lack of oxygen prevents decomposition of organic matter Shallow marine environments

Identification Texture – clastic, crystalline or bio-clastic Grain Size – size of the rock particles Composition – What is the rock made of?

Texture A. Clastic – whether or not the rock is composed of broken fragments of pre-existing rock (pebbles, sand, silt or clay) B. Non-clastic – no individual fragments, except perhaps pieces of shells - distinguished by mineral content i. crystalline ii. bioclastic

Grain Size Size of the rock sediments Pebbles, sand, silt or clay

Composition What is it made of?

HOW DO YOU KNOW IT’S A SEDIMENTARY ROCK It has: 1. Layers

It has: 2. Fossils

It has: 3. Compacted rock particles/sediments

ESRT Page 7