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Carbonera Formation, Mexico
The Carbonera Formation is a geologic formation in Mexico. It preserves fossils dating back to the Berriasian to Hauterivian stages of the Early Cretaceous The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Pro ... period. Fossil content The following fossils were reported from the formation: ;Ammonites * '' Maderia casitensis'' * '' Mexicanoceras laticostatum'' * '' M. multicostatum'' * '' ?Hemihoplites mexicanus'' * '' cf. Phylloceras serum'' * '' Distoloceras sp.'' ;Bivalves * '' Exogyra reedi'' * '' Plicatula pulchra'' * '' Gryphaea sp.'' ;Gastropods * '' Vermetus cornejoi'' * '' Pleurotomaria sp.'' ;Brachiopods * '' Ptilorhynchia (Proteorhynchia) durangensis'' ;Corals * '' Paretallonia hispaniensis'' See also * List of fossiliferous stratigraphic units in Mexico References ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Formation (stratigraphy)
A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics (lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exposed in a geographical region (the stratigraphic column). It is the fundamental unit of lithostratigraphy, the study of strata or rock layers. A formation must be large enough that it can be mapped at the surface or traced in the subsurface. Formations are otherwise not defined by the thickness (geology), thickness of their rock strata, which can vary widely. They are usually, but not universally, tabular in form. They may consist of a single lithology (rock type), or of alternating beds of two or more lithologies, or even a heterogeneous mixture of lithologies, so long as this distinguishes them from adjacent bodies of rock. The concept of a geologic formation goes back to the beginnings of modern scientific geology. The term was used by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plicatula
Plicatula is a genus of saltwater clams, marine bivalve molluscs, known commonly as kitten's paws or kittenpaws in the family Plicatulidae. MolluscaBase eds. (2022). MolluscaBase. Plicatula Lamarck, 1801. Accessed through: World Register of Marine Species at: https://www.marinespecies.org/aphia.php?p=taxdetails&id=204437 on 2022-01-31 Species * '' Plicatula angolensis'' Cosel, 1995 * '' Plicatula anomioides'' Keen, 1958 * '' Plicatula australis'' Lamarck, 1819 * '' Plicatula ceylanica'' G. B. Sowerby II, 1873 * ''Plicatula complanata'' Deshayes, 1863 * '' Plicatula dubia'' G. B. Sowerby II, 1847 * '' Plicatula gibbosa'' Lamarck, 1801 * '' Plicatula horrida'' Dunker, 1882 * † '' Plicatula hunterae'' Shaak and Nicol, 1974 * † '' Plicatula megaera'' (d'Orbigny, 1850) * '' Plicatula miskito'' Petuch, 1998 * '' Plicatula muricata'' G. B. Sowerby II, 1873 * '' Plicatula novaezelandiae'' G. B. Sowerby II, 1873 * '' Plicatula penicillata'' Carpenter, 1857 * '' Plicatula pernula'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sandstone Formations
Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) because they are the most resistant minerals to weathering processes at the Earth's surface. Like uncemented sand, sandstone may be any color due to impurities within the minerals, but the most common colors are tan, brown, yellow, red, grey, pink, white, and black. Since sandstone beds often form highly visible cliffs and other topography, topographic features, certain colors of sandstone have been strongly identified with certain regions. Rock formations that are primarily composed of sandstone usually allow the percolation of water and other fluids and are porosity, porous enough to store large quantities, making them valuable aquifers and petroleum reservoirs. Quartz-b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Valanginian Stage
In the geologic timescale, the Valanginian is an age or stage of the Early or Lower Cretaceous. It spans between 139.8 ± 3.0 Ma and 132.9 ± 2.0 Ma (million years ago). The Valanginian Stage succeeds the Berriasian Stage of the Lower Cretaceous and precedes the Hauterivian Stage of the Lower Cretaceous. Stratigraphic definitions The Valanginian was first described and named by Édouard Desor in 1853. It is named after Valangin, a small town north of Neuchâtel in the Jura Mountains of Switzerland. The base of the Valanginian is at the first appearance of calpionellid species ''Calpionellites darderi'' in the stratigraphic column. A global reference section (a GSSP) had in 2009 not yet been appointed. The top of the Valanginian (the base of the Hauterivian) is at the first appearance of the ammonite genus ''Acanthodiscus''. Subdivision The Valanginian is often subdivided in Lower and Upper substages. The Upper substage begins at the first appearance of ammonite species '' Sa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hauterivian Stage
The Hauterivian is, in the geologic timescale, an age in the Early Cretaceous Epoch or a stage in the Lower Cretaceous Series. It spans the time between 132.9 ± 2 Ma and 129.4 ± 1.5 Ma (million years ago). The Hauterivian is preceded by the Valanginian and succeeded by the Barremian.See Gradstein ''et al.'' (2004) for a detailed geologic timescale Stratigraphic definitions The Hauterivian was introduced in scientific literature by Swiss geologist Eugène Renevier in 1873. It is named after the Swiss town of Hauterive at the shore of Lake Neuchâtel. The base of the Hauterivian is defined as the place in the stratigraphic column where the ammonite genus '' Acanthodiscus'' first appears. A reference profile for the base (a GSSP) was officially ratified by the International Union of Geological Sciences in December of 2019, and is placed in La Charce, France. The top of the Hauterivian (the base of the Barremian) is at the first appearance of ammonite species ''Spit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Berriasian Stage
In the geological timescale, the Berriasian is an age/ stage of the Early/Lower Cretaceous. It is the oldest subdivision in the entire Cretaceous. It has been taken to span the time between 145.0 ± 4.0 Ma and 139.8 ± 3.0 Ma (million years ago). The Berriasian succeeds the Tithonian (part of the Jurassic) and precedes the Valanginian. Stratigraphic definition The Berriasian Stage was introduced in scientific literature by Henri Coquand in 1869. It is named after the village of Berrias in the Ardèche department of France. The largely non-marine English Purbeck Formation is in part of Berriasian age.In fact, the first rocks to be described of this age were the beds of the English Purbeck Formation, named as the Purbeckian by Alexandre Brongniart Alexandre Brongniart (5 February 17707 October 1847) was a French chemist, mineralogist, geologist, paleontologist, and zoologist, who collaborated with Georges Cuvier on a study of the geology of the region around Paris. Obs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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