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  2. Deicke and Millbrig bentonite layers - Wikipedia

    en.wikipedia.org/wiki/Deicke_and_Millbrig...

    The volcanic eruption that produced the Deicke K-bentonite bed which has been dated to 457.1 ±1.0, which was calculated using a concordant uranium-lead dating zircon fraction. [2] The Deicke and Millbrig eruptions have a minimal estimation of 600,000 km 2 (230,000 sq mi) covered and at least 1,122 km 3 (269 cu mi) of pre-compaction bentonite ...

  3. Tioga Bentonites - Wikipedia

    en.wikipedia.org/wiki/Tioga_Bentonites

    The Tioga Bentonites are a series of ash bed layers occurring in three Sedimentary basins in the eastern and midwestern United States. The primary basin they are found in is the Appalachian Basin, as well as the Illinois Basin and the Michigan Basin. Due to an unconformity these ash beds are not present in the southern Appalachians. [1]

  4. Bentonite - Wikipedia

    en.wikipedia.org/wiki/Bentonite

    Bentonite layers from an ancient deposit of weathered volcanic ash tuff in Wyoming Gray shale and bentonites (Benton Shale; Colorado Springs, Colorado). Bentonite (/ ˈ b ɛ n t ə n aɪ t / BEN-tə-nyte) [1] [2] is an absorbent swelling clay consisting mostly of montmorillonite (a type of smectite) which can either be Na-montmorillonite or Ca-montmorillonite.

  5. Marcellus Formation - Wikipedia

    en.wikipedia.org/wiki/Marcellus_Formation

    The Tioga ash beds contain bentonite clay which presents a landslide hazard in the unexcavated rock as well. [ 66 ] Damage to structures constructed on fill consisting of pyritic Marcellus shale has been caused by expansion from sulfuric acid (H 2 SO 4 ) runoff reacting with the calcite (CaCO 3 ) in the shale to produce gypsum (CaSO 4 ), which ...

  6. List of countries by bentonite production - Wikipedia

    en.wikipedia.org/wiki/List_of_countries_by...

    Bentonite usually forms from weathering of volcanic ash, most often in the presence of water. However, the term bentonite, as well as a similar clay called tonstein, have been used for clay beds of uncertain origin. For industrial purposes, two main classes of bentonite exist: sodium bentonite and calcium bentonite.

  7. Concretion - Wikipedia

    en.wikipedia.org/wiki/Concretion

    Groundwater containing methane or petroleum from underlying rock beds reacted with the iron oxide, converting it to soluble reduced iron. When the iron-bearing groundwater came into contact with more oxygen-rich groundwater, the reduced iron was converted back to insoluble iron oxide, which formed the concretions.

  8. National Register of Historic Places listings in Indiana ...

    en.wikipedia.org/wiki/National_Register_of...

    Location of Indiana County in Pennsylvania. This is a list of the National Register of Historic Places listings in Indiana County, Pennsylvania. This is intended to be a complete list of the properties and districts on the National Register of Historic Places in Indiana County, Pennsylvania, United States. The locations of National Register ...

  9. Flaser bed - Wikipedia

    en.wikipedia.org/wiki/Flaser_bed

    Flaser beds are a sedimentary, bi-directional, bedding pattern created when a sediment is exposed to intermittent flows, leading to alternating sand and mud layers. While flaser beds typically form in tidal environments, they can (rarely) form in fluvial conditions - on point bars or in ephemeral streams, or also in deep water environments when ...