نتایج جستجو برای: late cambrian
تعداد نتایج: 197730 فیلتر نتایج به سال:
late neoproterozoic-early cambrian schists have been occurred in southwest of zanjan city from the soltanieh belt. the soltanieh belt in northwest of iran is uplifted basement of precambrian-paleozoic in main central iran zone and includes outcrops of precambrian, paleozoic and mesozoic formations. late neoproterozoic-early cambrian schists, the oldest stratigraphy unit in the region, consist o...
The excellent preservation of the acritarchs, their great abundance, diversity and good stratigraphic control permit establishment of a detailed Middle and Late Cambrian acritarch biozonation. A total of 56 palynomorph species form the basis of 10 local acritarch assemblage zones. Assemblage zones I-II occur in the lower and middle parts of the Member C of the Mila Formation and suggest Early-m...
Cambrian sedimentary facies are exposed throughout north part of Kerman region. Trilobites’ faunas are the most common invertebrate fossils within the Cambrian strata. The section is made of 217 m of sandstone, shale, limestone and dolomite. In this study, 153 trilobite samples including seven species and genera were identified from the Dahu section 12 Km. east of Zarand. This trilobite’s assem...
cambrian sedimentary facies are exposed throughout north part of kerman region. trilobites’ faunas are the most common invertebrate fossils within the cambrian strata. the section is made of 217 m of sandstone, shale, limestone and dolomite. in this study, 153 trilobite samples including seven species and genera were identified from the dahu section 12 km. east of zarand. this trilobite’s assem...
to assess biogeographic affinity of the late cambrian (furongian) and the early ordovician (late tremadocian) faunas of eastern alborz, a multivariate cluster analysis using the pair-group raup-crick similarity index has been applied. the late cambrian fauna of alborz shows clear gondwanan signatures with the closest affinities to the contemporaneous faunas of temperate latitude peri-gondwana (...
cambrian sediments are widely exposed in the kerman province. parts of these deposits are containing trilobite fossils. one of the suitable areas for paleontological studies is kamar siah section. this section located about 60 km north east of kerman. these sediments have 200 m thickness with fossil invertebrates of trilobites, brachiopod, gastropods and stromatolite which includes kuhbanan and...
Burgess Shale-type deposits are renowned for their exquisite preservation of soft-bodied organisms, representing a range of animal body plans that evolved during the Cambrian 'explosion'. However, the rarity of these fossil deposits makes it difficult to reconstruct the broader-scale distributions of their constituent organisms. By contrast, microscopic skeletal elements represent an extensive ...
چکیده: به منظور مطالعه تریلوبیت های نهشته های کامبرین پیشین- پسین، برش دوراهی شهداد در جنوب شرق کرمان به ضخامت 270 متر انتخاب و از آن نمونه برداری به عمل آمد. این نهشته ها از سنگ آهک دولومیتی، ماسه سنگ، سنگ آهک نازک لایه فسیل دار و میان لایه هایی از شیل تشکیل شده و حاوی تریلوبیت ها، بازوپایان، اثر فسیل ها و استروماتولیت ها می باشد که از این میان تریلوبیت ها مورد شناسایی و بررسی قرار گرفته اند....
animal life on land. The current benchmark for evidence of plants on land is about 450,000,000 years ago (Late Ordovician). Tantalizing microscopic fossils of chemically resistant spore walls occur in land-derived rocks around the world, and predate this Late Ordovician age by over 50,000,000 years (Upper Cambrian) and possibly beyond. Figuring out what kinds of organisms (algae, primitive plan...
Late Cambrian to early Ordovician trilobites, the family Olenidae, were tolerant of oxygen-poor, sulfur-rich sea floor conditions, and a case is made that they were chemoautotrophic symbionts. Olenids were uniquely adapted to this habitat in the Lower Paleozoic, which was widespread in the Late Cambrian over Scandinavia. This life habit explains distinctive aspects of olenid morphology: wide th...
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