1. Sedimentary Rocks Earth Science Chapter 3 Section 3

2. B ELLWORK : ● How are igneous rocks formed?

3. T ODAY ’ S O BJECTIVES

4. E ARTH ’ S R ECORD K EEPER ● Form from sediment ● Broken-down pieces of other rocks and dirt ● Constitute about 75% of all rock outcrops on the continents ● Used to reconstruct much of Earth’s history ● Contain clues to past environments ● Provide information about sediment transport ● Often contain fossils

5. C LASSIFICATION ● Two groups based on source of materials ● Clastic (fragmented) sedimentary rocks ● Material is solid particles ● Classified by particle size ● Common rocks: Shale, Sandstone, Conglomerate, and Siltstone

6. C LASSIFICATION ( CONT.) ● Groups (cont.) ● Chemical sedimentary rocks ● Derived from material that was once in solution and precipitated to form sediment (or through life processes) ● Common Sedimentary Rocks ● Limestone: (the most abundant chemical rock) Coquina, Chalk, and Travertine ● Microcrystalline Quartz (precipitated quartz): Chert, Flint, Jasper, Agate ● Evaporites: Rock Salt and Gypsum ● Coal: Lignite and Bituminous

7. F ORMATION ● Produced through lithification ● Loose sediments are transformed into solid rock ● Lification processes ● Compaction ● Cementation by ● Calcite ● Silica ● Iron Oxide

8. F EATURES ● Strata, or beds (most characteristic) ● Bedding planes separate strata ● Fossils ● Contain traces or remains of prehistoric life ● Are the most important inclusions ● Help determine past environments ● Are used as time indicators ● Are used for matching rocks from different places

9. C OMMERCIAL U SE ● Economic importance ● Coal ● Petroleum and natural gas ● Sources of iron and aluminum ● Raw materials for concrete and building

10. S CHEME FOR S EDIMENTARY ROCK I DENTIFICATION http://www.youtube.com/watch?v=NWQLmGu8fSg