Unformatted text preview: ter> 2mm, Peloids is spherical grains composed of Microcrystalline carbonates but with non inertial structure • Skeletal grains: Mollusca, Brachiopods, Cnidarians, Foraminifera, Sponges, Arthropods & Calcispheres • Algae: Rhodophyta, Chlorophyta, Chyrophyta, Cyanophyta 2. Matrix: • Micrite: formed of calcareous particles ranging in diameter from 0.06 to 2 mm that have been deposited mechanically rather than from solution 3. Cement: • Sparite: is coarser than Micrite, with a grain size of > 4µm and is crystalline Classification of Limestone: Limestone Ooids Peloids 1. According to grain size: ‐Calci Rudite(2>mm) ‐Calci Renite(2mm:64µm) ‐Calci Lutite(<64µm) 2. According to Dunham1962: a‐Grain Stone(grains without matrix) b‐Grains in contact with matrix c‐Wacke Stone: Coarse grains floating in matrix d‐Mud Stone: Matrix with few grains 3. According to Embry&Klovan 1972: a‐Coarse grain size: Float stone & Rud stone b‐Organic bending during deposition: Baffle Stone, Bind Stone & Frame stone B‐Dolomite composed of calcium magnesium carbonate CaMg(CO3)2 (known as magnesium L.S) C‐Chalk It is a soft, white, porous, a form of limestone forms under relatively deep marine conditions from the gradual accumulation of minute calcite plates Chalk is composed mostly of calcium carbonate with minor amounts of silt and clay. It is common to find Chert nodules embedded in chalk. Chalk Chalk can also refer to other compounds including magnesium silicate and calcium sulfate. 9 Geology & Geophysics in Oil Exploration Mahmoud Sroor Dolomite Geology & Geophysics in Oil Exploration D‐Marl It is a calcium carbonate or lime‐rich mud formed from porous mass of shells & shell fragments accumulate on the bottom of fresh water lakes E‐Coquina L.S composed of loosely aggregated shells & shell fragments F‐Travertine Travertine is a terrestrial sedimentary rock, formed by the precipitation of carbonate minerals from solution in ground and surface waters Travertine forms the stalactites...
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- Spring '10
- Geology, Volcano, Tephra, Volcanic Ash, Geology & Geophysics, Mahmoud Ahmed Sroor