Sediment1 - sink to the seafloor. Under special...

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Sediments Limestone Shale Rocks There are three types of rocks: Igneous rocks, Metamorphic rocks and sedimentary rocks. Igneous rock form by the cooling of magma. Metamorphic rocks form by exposing already existing sediments to high temperatures or pressure (deep in the earth's crust). Fossils only occur in sedimentary rocks which are described below. Sedimentary rocks Most sedimentary rocks are formed when erosion products are deposited in layers, and over time lithifies into rock. Erosion products are the materials that form during erosion of rocks by water, ice, wind, etc. This is how conglomerates (pebble stone), sandstones and shales form. These rocks are ultimately erosion products of igneous rocks. Conglomerate Sandstone Other sedimentary rocks do not originate from erosion products. For example, peat can compact and lithify into coal. Limestone forms when little chalk skeletons of sea organisms
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Unformatted text preview: sink to the seafloor. Under special circumstances some sedimentary rocks can form by precipitation of dissolved chemicals from the seawater. For example gypsum and rocksalt. Time, high pressure (when sediments are buried deep in the earth's crust), and high temperature will cause loose sediments to lithify into rocks. This is the result of compaction and several chemical processes in the sediment. When sediments are buried deep in the earth's crust, or exposed to high temperatures, new types of rocks can be formed as a result. Fossils usually do not survive this process. The rocks that are formed are described in the table below: Original: Rock: Slightly metamorphic rock: Metamorphic rock:--> Higher temperature and pressure--> clay Shale Phylite / Schist Metamorphic rocks like gneiss sand Sandstone Quartzite chalk Limestone Marble...
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Sediment1 - sink to the seafloor. Under special...

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