نتایج جستجو برای: diagenetic origin
تعداد نتایج: 200395 فیلتر نتایج به سال:
Site U1317 (proposal Site PORC-3A) is located on the northwest shoulder of the Challenger Mound (51o 22.8 N, 11o 43.1W, in 781 to 815 m water depth). Scientific drilling of the Challenger Mound was the central objective of Expedition 307. Specific objectives of drilling Site U1317 were: • To establish whether the mound base is on a carbonate hardground of microbial origin and whether past geofl...
the purpose of the present study is to find out whether bilinguals of khuzestan-arab origin or monolinguals of iranian origin code-switch during learning or speaking english and which group is more susceptible to code-switch. to this end, the students of 24 classes from high schools and pre- university centers were screened out, and interviewed and their voices and code-switchings were recorded...
Opportunity has investigated in detail rocks on the rim of the Noachian age Endeavour crater, where orbital spectral reflectance signatures indicate the presence of Fe(+3)-rich smectites. The signatures are associated with fine-grained, layered rocks containing spherules of diagenetic or impact origin. The layered rocks are overlain by breccias, and both units are cut by calcium sulfate veins p...
The diagenetic changes of the Lower-Middle Eocene limestones in the area to the west of AssiutMinia Stretch include the following processes: compaction, cementation, neomorphism, silicification, glauconitization and ferrugination. The compaction is represented by mechanical and chemical types. Cementation is either shallow submarine (represented by micrite, fibrous calcite and isopachous calcit...
The Sachun Formation (Paleocene-Lower Eocene) is mainly composed of carbonates and evaporates that were deposited in shallow-marine evaporitic mudflat environments. The Sachun Formation in the study area has been divided into three units including: lower evaporate; middle bioclastic limestone and upper evaporate. It is mainly composed of diagenetic gypsum, which originated from dehydration of a...
a brief account of the representative and workable industrial minerals namely magnesite, talc and barite in lesser himalaya, is presented here emphasizing their genesis. deposits of magnesite and talc are found associated with neoproterozoic, plateform type, shelf-slope limestone-dolomite host rocks from inner lesser himalayan sequences. field, textural, geochemical signatures and fluid inclusi...
source of cement in the great oolite reservoir, storrington oil field, weald basin, south of england
the source of cement in oilfields is critical to the prediction of the distribution of cements in the reservoirs and also prediction of reservoir quality. the source of mineral forming cements has been determined for the storrington oolitic carbonate reservoir (middle jurassic great oolite formation, weald basin, onshore uk) using a combination of petrography, electron microscopy, fluid inclusi...
Pyritic shale horizons of the Newland Formation (Belt Series, Mid-Proterozoic) show striking similarities to Proterozoic pyritic shales elsewhere that are host to major lead-zinc deposits, such as Mt. Isa and McArthur River. However, in contrast to these deposits the pyritic shales of the Newland Formation contain only minute quantities of lead and zinc. Elevated concentrations of lead and zinc...
The exploitation of mollusks by the first anatomically modern humans is a central question for archaeologists. This paper focuses on level 8 (dated around ∼ 100 ka BP) of El Harhoura 2 Cave, located along the coastline in the Rabat-Témara region (Morocco). The large quantity of Patella sp. shells found in this level highlights questions regarding their origin and preservation. This study presen...
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