نتایج جستجو برای: upper permian
تعداد نتایج: 207735 فیلتر نتایج به سال:
Morrowan-age units in the Permian Basin appear to show a “second-order” transgression from siliciclastic fluvial-deltaic to shallow-marine and subsequently to carbonate deposition. In general, Morrowan-age siliciclastics dominate deposition in the west of the Permian Basin, while carbonate deposition dominates in the east. The predominance of carbonate facies in the east is due to a lack of sil...
Alexarasniidaefam. n. and Alexarasnia rossicagen. et sp. n. are described from the Upper Permian of European Russia. Systematic position of this enigmatic family within the infraclass Polyneoptera is unclear.
Atokan-age units in the Permian Basin record a 2-order transgression, with aerially restricted, lower Atokan fluvial to shallow-marine siliciclastics followed by pervasive carbonate deposition. In general, Atokan-age siliciclastics dominated deposition in the west of the Permian Basin while carbonate deposition dominated throughout the rest of the basin. Predominance of carbonate facies across ...
Today, cycads are a small group of gymnospermous plants with a limited distribution in the (sub)tropics, but they were major constituents of Mesozoic floras. Fossil leaves sporadically found in latest Carboniferous and Permian floras have putatively been ascribed to cycads. However, their true affinity remains unclear due to the lack of anatomical evidence. Virtually all modern cycads have pinn...
Rhythmic sandstone-mudstone-coal succession of the Barakar Formation (early Permian) manifests a transition from lower braided-fluvial to upper tide-wave influenced, estuarine setting. Monospecific assemblage of marine trace fossil Chondrites isp. in contemporaneous claystone beds in the upper Barakar succession from two Gondwana basins (namely, the Raniganj Basin and the Talchir Basin) in east...
The Paleozoic sediments of the Chal-i-Sheh area in southwestern Iran comprising of Mila Formation, Ilebek Formation and Faraghan Formation, were studied palynologically. The samples containing well-preserved palynomorphs include acritarchs, chitinozoans, scolecodonts and pollenlspores. A palynological zonation has been established and comparison was made with other parts of the world. Based...
Based on seven measured sections from Svalbard, the marine strata of the Permian Kapp Starostin Formation are arranged into seven transgressive–regressive sequences (TR1–TR7) of c. 4– 5 Ma average duration, each bound by a maximum regressive surface. Facies, including heterozoandominated limestones, spiculitic cherts, sandstones, siltstones and shales, record deposition within inner, middle and...
Four supergiant and numerous giant gasfields have been discovered in the Southwest Iran which produce from Permian-Triassic carbonates belong to the upper member of Dalan Formation and Kangan Formation. In this research a detailed biostratigraphic, microfacies and sequence stratigraphic study of the late Middle Permian to Triassic successions was undertaken from 850 thin sections prepared from ...
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