Phosphogenesis

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August undefined, 2024

WebRepetitive cycles of deposition, phosphogenesis, re-exposure and reworking, and deposition (Baturin Cycles), caused by current-induced lateral migration of sand bodies, shaped the internal stratification and composition of the condensed phosphatic beds. Catastrophic burial of entire benthic communities was crucial to phosphogenesis. WebPhosphogenesis either occurred around preformed phosphatic particles, which were partly covered by a new generation of phosphate, thereby producing lenticular, eye-shaped …

Geochemical characteristics of Triassic and Cretaceous …

WebThe Permian was a remarkable time period. It represents the maximum stage of Pangean continental assembly, includes a major global climatic shift from glacial to nonglacial conditions (icehouse-greenhouse transition), and is ter minated by one of the most profound faunal/floral extinction events in the Earth's history. WebMar 28, 2009 · An analysis of rare earth elements in various types of supergene phosphorites established the following sequence of increasing average total contents (ppm): phosphorite from Christmas Island in the Indian Ocean, 3.89; spelean coprolitic phosphorite, 21.98; phosphorite from the weathering zone of sedimentary rocks, 27.41; … small printer olympus tough camera tg-4

Marine Phosphogenesis in Shallow-Water Environments

WebAbstract Sedimentary facies, depositional environments and stratigraphic relationships of the Upper Cretaceous Duwi, Sibâîya and Phosphate Formations in Egypt are summarized in order to shed light on the origins and interrelationships between phosphorites and their commonly associated facies. WebJun 21, 2013 · Here, we present the remains of modern sulfide-oxidizing bacteria that are partially encrusted in apatite, providing evidence that bacterially mediated phosphogenesis can rapidly permineralize... WebThe formation of phosphatic sediments is coupled to global climate fluctuations, biological cycling of phosphorus and local redox conditions. Although the processes involved in phosphogenesis are well described, high-resolution data on the redox and stable isotope systematics in Recent in-situ phosphorites are scarce. small printer scanner for laptop

CDC Phosgene Public Health Emergency Preparedness & Response

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WebJan 21, 2005 · Phosphorite deposits in marine sediments are a long-term sink for an essential nutrient, phosphorus. Here we show that apatite abundance in sediments on … WebAn upwelling flux triggered phosphogenesis, promoting the early lithification of the sea floor on the platforms. After upwelling event neritic carbonate production could not be re-established on the Latium-Abruzzi platform because of the persisting eutrophic conditions and the high rates of tectonic subsidence and terrigenous input linked to ... small printer sticker machineWebPhosphorites are sedimentary formations enriched in Ca-phosphate minerals. The precipitation of these minerals is thought to be partly mediated by the activity of microorganisms. The vast majority of studies on phosphorites have focused on a petrological and geochemical characterization of these rocks. small printer stand with file drawer

"WebMay 1, 2005 · Minor lithologies include volcanic ash, dolomite, porcelanite and chert, and condensed phosphatic beds. Sediments dated as 14.3–13.5 Ma have average total … " - Phosphogenesis

Phosphogenesis

WebPhosphogenesis occurs in sediments beneath some oceanic upwelling zones that harbor polyphosphate-accumulating bacteria. These bacteria are believed to concentrate phosphate in sediment pore waters, creating supersaturated conditions with respect to apatite precursors. WebThe phosphorus cycle, phosphogenesis and marine phosphate-rich deposits Föllmi, K. B. Phosphorus (in the form of phosphate) is an essential nutrient and energy carrier on many different levels of life, and a key element in mediating between living and lifeless parts of …

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WebDec 1, 2024 · The Ediacaran-early Cambrian period is not only the key period of global climate and life evolution, but also recorded the occurrence of the second large-scale phosphogenesis event in history of... WebAug 13, 2024 · Regeneration of allochtonous-P from fish bone dissolution may contribute to the P-cycle of many aquatic systems. Recently, Salama et al. supposed the bioerosion of bones is an important source for P required for phosphogenesis. Based on the above-mentioned assumptions, the phosphogenesis model could be approached.

WebJun 16, 2009 · An early-diagenetic mildly reducing environment is suggested by the presence of authigenic (subsequently reworked) pyrite, which contrasts with the syndepositional normal oxygenated conditions reflected by macroburrowing and the abundance of benthic fossils. Keywords carbonate productivity apatite glauconite … WebFeb 13, 2024 · Deep-sea sediments with high contents of rare-earth elements and yttrium (REY) are expected to serve as a potential resource for REY, which have recently been proved to be mainly contributed by phosphate component. Studies have shown that the carriers of REY in deep-sea sediments include aluminosilicate, Fe-Mn oxyhydroxides, and phosphate …

WebSignificant information on the nature of phosphogenesis has been acquired from the study of the stable isotopes of oxygen, carbon, and sulfur. Oxygen. Francolite has the unique property of containing oxygen in two distinct sites, … WebDec 1, 1990 · OSTI.GOV Journal Article: Phosphogenesis and weathering of shelf sediments from the southeastern United States: Implications for Miocene. delta. sup 13 C excursions and global cooling Phosphogenesis and weathering of shelf sediments from the southeastern United States: Implications for Miocene. delta. sup 13 C excursions and …

WebModern bacteria associated with phosphogenesis store polyphosphate intracellularly under aerobic conditions, which they release when conditions become anoxic. Although bacteria …

WebCheryl B. Bast, Dana F. Glass-Mattie, in Handbook of Toxicology of Chemical Warfare Agents (Third Edition), 2024 23.8 Concluding remarks and future directions. Phosgene is a … small printer scanner compatible with macWebNov 17, 2013 · Given that these bacteria are known to mediate phosphogenesis, we conclude that the nodules are fossilized sulphur-oxidizing bacteria. highlights which way usa full setWebDec 7, 2024 · Eesti fosforiidi tekkelugu sai oluliselt selgemaks. Keskkond. Marko Mägi (TÜ) 07.12.2024 00:21. 4. Tartu Ülikooli ökoloogia ja maateaduste instituudi geoloogia nooremteadur Kaarel Lumiste. Autor/allikas: Peeter Paaver. Tartu Ülikoolis kaitstud doktoritöö aitab paremini mõista, millistes tingimustes Eestis viimasel ajal palju kõneainet … small printer scanner fax machineWebJun 16, 2009 · Phosphogenesis is a biogeochemical process governed by microbially mediated Eh and pH of bottom and pore waters, dissolved chemical elements and … small printer scanner wirelessWebPhosgene. Phosgene is a highly toxic gas produced by the burning of chlorinated hydrocarbons or the action of ultraviolet radiation on such compounds. Phosgene reacts … highlights while pregnantWebEarly Cambrian foreland phosphogenesis in the Khuvsgul Basin of Mongolia Jun 2024 Constraining Neoproterozoic climate change in Tigray, Ethiopia small printer stand with drawersWebAug 5, 2024 · Likewise, phosphate minerals have only rarely been documented in ancient seep deposits (Peckmann et al., 2005), although microbially induced phosphogenesis may have occurred in marine environments since the Precambrian (Soudry and Champetier, 1983; Williams and Reimers, 1983; Dahanayake and Krumbein, 1985; Bailey et al., 2007, 2013). small printer shelf