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  2. Concretion - Wikipedia

    en.wikipedia.org/wiki/Concretion

    Concretions in Torysh, Western Kazakhstan Concretions with lens shape from island in Vltava river, Prague, Czech Republic Marlstone aggregate concretion, Sault Ste. Marie, Michigan, United States A concretion is a hard and compact mass formed by the precipitation of mineral cement within the spaces between particles, and is found in sedimentary ...

  3. Manganese nodule - Wikipedia

    en.wikipedia.org/wiki/Manganese_nodule

    Assessment of the changing paleoclimate conditions during soil evolution can be explored by analyzing the nodule's concretion structure when combined with dating techniques. [2] Manganese layers typically form at higher redox potentials compared to iron layers, but a period of rapid increase in redox potential can form a mixed layer. [2]

  4. Pseudofossil - Wikipedia

    en.wikipedia.org/wiki/Pseudofossil

    One common example is when manganese oxides crystallize with a characteristic tree-like or dendritic pattern along a rock fracture. The formation of frost dendrites on a window is another common example of this crystal growth. Concretions are sometimes thought to be fossils, and occasionally one contains a fossil, but are generally not fossils ...

  5. Coal ball - Wikipedia

    en.wikipedia.org/wiki/Coal_ball

    A coal ball is a type of concretion, varying in shape from an imperfect sphere to a flat-lying, irregular slab.Coal balls were formed in Carboniferous Period swamps and mires, when peat was prevented from being turned into coal by the high amount of calcite surrounding the peat; the calcite caused it to be turned into stone instead.

  6. Wikipedia : Picture peer review/Sandstone concretion

    en.wikipedia.org/.../Sandstone_concretion

    A concretion is a volume of sedimentary rock in which a mineral cement fills the porosity (i.e. the spaces between the sediment grains). The image shows a Sandstone Concretion in the wall at the beach of Año Nuevo State Reserve. This concretion was too high in the wall to place a ruler, but I estimate it to be about 400 mm long.

  7. Limonite - Wikipedia

    en.wikipedia.org/wiki/Limonite

    Limonite concretion from the spoil bank of a uranium mine. Nickel-rich limonite ores represent the largest reserves of nickel. Such minerals are classified as lateritic nickel ore deposits. [17] One of the first uses was as a pigment. The yellow form produced yellow ochre for which Cyprus was famous, [18] while the darker forms produced more ...

  8. Lithification - Wikipedia

    en.wikipedia.org/wiki/Lithification

    Concretion – Compact mass formed by precipitation of mineral cement between particles; Diagenesis – Physico-chemical changes in sediments occurring after their deposition; Lithology – Description of the physical characteristics of a rock unit; Parent rock – Original rock substratum; Petrifaction – Process of fossilisation

  9. Mazon Creek fossil beds - Wikipedia

    en.wikipedia.org/wiki/Mazon_Creek_fossil_beds

    The Mazon Creek fossil beds are a conservation lagerstätte found near Morris, in Grundy County, Illinois.The fossils are preserved in ironstone concretions, formed approximately in the mid-Pennsylvanian epoch of the Carboniferous period.