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  2. Chalk - Wikipedia

    en.wikipedia.org/wiki/Chalk

    Chalk is so common in Cretaceous marine beds that the Cretaceous Period was named for these deposits. The name Cretaceous was derived from Latin creta, meaning chalk. [10] Some deposits of chalk were formed after the Cretaceous. [11] The Chalk Group is a European stratigraphic unit deposited during the late Cretaceous Period.

  3. List of alchemical substances - Wikipedia

    en.wikipedia.org/wiki/List_of_alchemical_substances

    Lye – potash in a water solution, formed by leaching wood ashes. Potash – potassium carbonate, formed by evaporating lye; also called salt of tartar. K 2 CO 3; Pearlash – formed by baking potash in a kiln. Milk of sulfur (lac sulphuris) – formed by adding an acid to thion hudor (lime sulfur). Natron/soda ash/soda – sodium carbonate ...

  4. Evaporite - Wikipedia

    en.wikipedia.org/wiki/Evaporite

    A cobble encrusted with halite evaporated from the Dead Sea, Israel (with Israeli ₪1 coin [diameter 18mm] for scale). An evaporite (/ ɪ ˈ v æ p ə ˌ r aɪ t /) is a water-soluble sedimentary mineral deposit that results from concentration and crystallization by evaporation from an aqueous solution. [1]

  5. Solutional cave - Wikipedia

    en.wikipedia.org/wiki/Solutional_cave

    A solutional cave, solution cave, or karst cave is a cave usually formed in a soluble rock like limestone (Calcium carbonate CaCO 3). It is the most frequently occurring type of cave. It can also form in other rocks, including chalk, dolomite, marble, salt beds, and gypsum. [1]

  6. Niobrara Formation - Wikipedia

    en.wikipedia.org/wiki/Niobrara_Formation

    Niobrara Chalk was weathered and opalized in the Valentine phase of the Ogallala Formation. The Niobrara Formation / ˌ n aɪ. ə ˈ b r ær ə /, also called the Niobrara Chalk, is a geologic formation in North America that was deposited between 87 and 82 million years ago during the Coniacian, Santonian, and Campanian stages of the Late ...

  7. Marine biogeochemical cycles - Wikipedia

    en.wikipedia.org/wiki/Marine_biogeochemical_cycles

    Water is the medium of the oceans, the medium which carries all the substances and elements involved in the marine biogeochemical cycles. Water as found in nature almost always includes dissolved substances, so water has been described as the "universal solvent" for its ability to dissolve so many substances.

  8. Gypsum - Wikipedia

    en.wikipedia.org/wiki/Gypsum

    Gypsum is moderately water-soluble (~2.0–2.5 g/L at 25 °C) [13] and, in contrast to most other salts, it exhibits retrograde solubility, becoming less soluble at higher temperatures. When gypsum is heated in air it loses water and converts first to calcium sulfate hemihydrate ( bassanite , often simply called "plaster") and, if heated ...

  9. Cretaceous - Wikipedia

    en.wikipedia.org/wiki/Cretaceous

    The Cretaceous is justly famous for its chalk; indeed, more chalk formed in the Cretaceous than in any other period in the Phanerozoic. [27] Mid-ocean ridge activity—or rather, the circulation of seawater through the enlarged ridges—enriched the oceans in calcium ; this made the oceans more saturated, as well as increased the ...