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Lipeón Formation
The Lipeón Formation is a Telychian to Pridoli geologic formation of southern Bolivia and northwestern Argentina. The formation comprises sandstones and siltstones. Plant fossils comprising rhyniophytes (specifically ''Aberlemnia'', ''Steganotheca'', '' Tarrantia'', ''Hostinella'' and '' Cooksonia'') are scattered throughout, with some abundant concentrations on micaceous bedding plains. The fossil flora is the oldest of South America.Jarcas stream, Negra Muerta, Sella Valley, Tarija at .org [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geological Formation
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 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 Abraham Gottlob Wer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hostinella
''Hostinella'' is a form genus, used for bare dichotomously branching stems (axes) which have not been found in association with spore-forming organs or sporangia and so cannot be assigned to a more precise genus or species. Specimens assigned to this genus have been found in Bathurst Island, Canada, in the Bertie Formation of Upper Silurian age (around ), where the stems are approximately 1.2 mm in diameter; and in Lower Devonian Senni beds (from around ) where the axes have a straited external appearance and contain xylem with tracheids (diameter: 40 µm). It is known to co-occur with ''Krithodeophyton ''Krithodeophyton'' is a genus of lower Devonian plant with branching axes. It is considered to be a barinophyte. Phylogeny The phylogenetic position of the barinophytes remains disputed. Kenrick and Crane in 1997 called the group the Barinophy ...''. References Silurian plants Early Devonian plants Prehistoric plant genera Silurian first appearances E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Fossiliferous Stratigraphic Units In Bolivia
This is a list of fossiliferous stratigraphic units in Bolivia. __NOTOC__ List of fossiliferous stratigraphic units See also * * Gomphothere fossils in Bolivia * South American land mammal ages * List of fossiliferous stratigraphic units in Paraguay * List of fossiliferous stratigraphic units in Peru References Bibliography * * ;Cajones Formation * ;Casira Formation * ;Cerdas beds * ;Honda Group * * * * ;Lacayani fauna * ;Mesón Group * ;Los Monos Formation * ;Ñuapua Formation * ;La Puerta Formation * ;Puncoviscana Formation * ;Quehua Formation * ;Salla Formation * * * ;Santa Lucía Formation * * * * * * * * * ;Tarija Formation * ;Toro Toro Formation * * ;Umala Formation * ;Yecua & Petaca Formations * Further reading * ;Mesozoic * L. Branisa. 1968. Hallazgo del amonite Neolobites en la Caliza Miraflores y de huellas de dinosaurios en la formación El Molino y su significado para la determinación de la ed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lingulata
Lingulata is a class of brachiopods, among the oldest of all brachiopods having existed since the Cambrian period (). They are also among the most morphologically conservative of the brachiopods, having lasted from their earliest appearance to the present with very little change in shape. Shells of living specimens found today in the waters around Japan are almost identical to ancient Cambrian fossils. The Lingulata have tongue-shaped shells (hence the name Lingulata, from the Latin word for "tongue") with a long fleshy stalk, or pedicle, with which the animal burrows into sandy or muddy sediments. They inhabit vertical burrows in these soft sediments with the anterior end facing up and slightly exposed at the sediment surface. The cilia of the lophophore generate a feeding and respiratory current through the lophophore and mantle cavity. The gut is complete and J-shaped. Lingulata shells are composed of a combination of calcium phosphate, protein and chitin. This is unlike most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slimonia
''Slimonia'' is a genus of eurypterid, an extinct group of aquatic arthropods. Fossils of ''Slimonia'' have been discovered in deposits of Silurian age in South America and Europe. Classified as part of the family Slimonidae alongside the related ''Salteropterus'', the genus contains three valid species, ''S. acuminata'' from Lesmahagow, Scotland, ''S. boliviana'' from Cochabamba, Bolivia and ''S. dubia'' from the Pentland Hills of Scotland and one dubious species, ''S. stylops'', from Herefordshire, England. The generic name is derived from and honors Robert Slimon, a fossil collector and surgeon from Lesmahagow. Out of the four described species of ''Slimonia'', three measured below or up to in length. Only ''S. acuminata'' was larger, with the largest specimens measuring in length. Though this is large for a predatory arthropod, ''Slimonia'' would be exceeded in length by later and more derived (more "advanced") members of the closely related pterygotid family of eurypterid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shale Gas
Shale gas is an unconventional natural gas that is found trapped within shale formations. Since the 1990s a combination of horizontal drilling and hydraulic fracturing has made large volumes of shale gas more economical to produce, and some analysts expect that shale gas will greatly expand worldwide energy supply. Shale gas has become an increasingly important source of natural gas in the United States since the start of this century, and interest has spread to potential gas shales in the rest of the world. China is estimated to have the world's largest shale gas reserves. A 2013 review by the United Kingdom Department of Energy and Climate Change noted that most studies of the subject have estimated that life-cycle greenhouse gas (GHG) emissions from shale gas are similar to those of conventional natural gas, and are much less than those from coal, usually about half the greenhouse gas emissions of coal; the noted exception was a 2011 study by Howarth and others of Co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shale Oil
Shale oil is an unconventional oil produced from oil shale rock fragments by pyrolysis, hydrogenation, or thermal dissolution. These processes convert the organic matter within the rock (kerogen) into synthetic oil and gas. The resulting oil can be used immediately as a fuel or upgraded to meet refinery feedstock specifications by adding hydrogen and removing impurities such as sulfur and nitrogen. The refined products can be used for the same purposes as those derived from crude oil. The term "shale oil" is also used for crude oil produced from shales of other unconventional, very low permeability formations. However, to reduce the risk of confusion of shale oil produced from oil shale with crude oil in oil-bearing shales, the term "tight oil" is preferred for the latter. The International Energy Agency recommends to use the term "light tight oil" and World Energy Resources 2013 report by the World Energy Council uses the term "tight oil" for crude oil in oil-bearing sha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Source Rock
In petroleum geology, source rock is rock which has generated hydrocarbons or which could generate hydrocarbons. Source rocks are one of the necessary elements of a working petroleum system. They are organic-rich sediments that may have been deposited in a variety of environments including deep water marine, lacustrine and deltaic. Oil shale can be regarded as an organic-rich but immature source rock from which little or no oil has been generated and expelled. Subsurface source rock mapping methodologies make it possible to identify likely zones of petroleum occurrence in sedimentary basins as well as shale gas plays. Types of source rocks Source rocks are classified from the types of kerogen that they contain, which in turn governs the type of hydrocarbons that will be generated: * Type I source rocks are formed from algal remains deposited under anoxic conditions in deep lakes: they tend to generate waxy crude oils when submitted to thermal stress during deep burial. * Type ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kirusillas Formation
The Kirusillas Formation is a Homerian geologic formation of central Bolivia. The formation comprises black shales, overlies the Llallagua Formation and is overlain by the Pampa and Guayabillas Formations. The Kirusillas Formation is laterally equivalent to the Lipeón Formation.Veizaga Saavedra et al., 2014, p.96 at .org The formation is a potential for |
Hungerfordia (alga)
''Hungerfordia'' is a genus of presumed marine algae first described by Fry and Banks in 1955 in describing ''Hungerfordia dichotoma'' from Late Devonian strata. It has been interpreted as a probable brown (Phaeophyte) algae though the possibility that it represents a red ( Rhodophyte) alga is not excluded - the taxonomic challenge being that modern red and brown algae are differentiated on the basis of colour and cellular structure which are not preserved in the fossil taxa (Hiller and Gess, 1996, Gess and Whitfield). Douglas and Jell (1985) suggested that ''Buthotrephis trichotoma'' and ''B. divaricata'' should furthermore be transferred from ''Buthotrephis'' to ''Hungerfordi''a. A further species, ''Hungerfordia fionae'' from the Late Devonian of South Africa is known from the largest sample, analysis of which suggests that variations used to differentiate between ''H. dichotoma'' and ''H. trichotoma'' may represent growth variations accountable by a single taxon. ''Hungerfo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
