Unformatted text preview: separated into these categories There are many types of Mud Rocks: • • • • • • Clay & Clay Stone: is a hydrous Aluminum Silicates with a specific sheet structure (<4µm) Mud & Mudstone: is a mixture of Clay & Silt grade material (4:62µm), Mudstone is a black non fossil rock, where Shale is laminated & thin sheets Clay stone Argillite: is a mud rock but more indurate Slate: Mud rocks metamorphose into Slate Shale: formed from clay that is compacted together by pressure Loess: yellow to buff-colored clastic deposits composed of silt-sized grains Well sorted nature, angular shape, unstartified but may contain Shells & concretions Organic Rich Mud rock: are black shale & Carbonaceous Mud rock which contain 3:10% organic carbon Their importance lies in their potential as source rocks for oil Argillite Siltstone: Clay stone contains more Silt‐sized particles Siltstone lacks to the fissility & lamination • • Mineral components of Mud Rocks: • Clay minerals (si2O5) • Kandite group (Kaolinite, Dickite, Nacrite) • Smectic group (Montmorillonite) • Vermiculite, Illite, Glauconite, Sepotite Quartz, Feldspars, Muscovite Shale • Silt Stone 8 Geology & Geophysics in Oil Exploration Mahmoud Sroor Geology & Geophysics in Oil Exploration 2‐Carbonate Sediments A‐Limestone Limestone is a sedimentary rock composed largely of the mineral calcite (calcium carbonate: CaCO3). Like most other sedimentary rocks, limestones are comprised of grains, however, around 80‐90% of limestone grains are skeletal fragments of marine organisms such as coral or foraminifera. Other carbonate grains comprising limestones are ooids, peloids, intraclasts, and extraclasts. Some limestones do not consist of grains at all and are formed completely by the chemical precipitation of calcite or aragonite. I.e. Travertine. Components of Limestone: 1. Grains: • Non Skeletal grains: Ooids: spherical or sub spherical grains concentrated around a nucleus (0.2:.5mm), Pisolites: is Ooids with diame...
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- Spring '10
- Geology, Volcano, Tephra, Volcanic Ash, Geology & Geophysics, Mahmoud Ahmed Sroor