Shale
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Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals and tiny fragments of other minerals, especially quartz and calcite. Shale is characterized b
Shale
Sample of drill cuttings of shale while drilling an oil well in Louisiana, United States. Sand grain = 2 mm in diameter
Color chart for shale based on oxidation state and organic carbon content
Shale in Potokgraben, the Karawanks, Austria
Clay
Videos
Clay is a type of fine-grained natural soil material containing clay minerals. Most pure clay minerals are white or light-coloured, but natural clays show a variety of colours from impurities, such as
Shale
…Atlantic, and in part because the very warm Cretaceous seas lacked the circulation of cold bottom water that oxygenates the deep oceans today. Most clay must be deposited as aggregates and floccules, since the settling rate of individual clay particles is extremely slow. Flocculation is very rapid once…
Boulder clay cliff south of Withernsea, England
A 23,500 times magnified electron micrograph of smectite clay
Italian and African-American clay miners in mine shaft, 1910
Clay layers in a construction site in Auckland, New Zealand. Dry clay is normally much more stable than sand in excavations.