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...

The Cambrian Burgess Shale-type biotas form a globally consistent ecosystem, usually dominated by arthropods. Elements of these communities continued into the Early Ordovician at high latitude, but our understanding of ecological changes during the Great Ordovician Biodiversification Event (GOBE) is currently limited by the paucity of Ordovician exceptionally preserved open-marine faunas. Here ...

A well-preserved Cambrian section in the Zanskar Valley of northern India has previously been interpreted to record the transition from a passive to an active tectonic margin related to Cambrian–Ordovician orogenesis. This interpretation has been used to support the tectonostratigraphic interpretation of other successions across the Tethyan Himalaya. Our detailed paleoenvironmental analysis sig...

We present new geologic maps of the Lake Champlain region of west-central Vermont and east-central New York State. This region contains a shallow-crustal section of an Ordovician foreland basin and a far-traveled thrust system that transported the Upper Cambrian–Lower Ordovician platform-sequence, allochthonous risefacies pelites and arenites and Middle Ordovician basinal shales and flysch. Ear...

The upper part of Shirgesht (UPS) and lower part of Niur (LPN) formations (Ordovician-Silurian) consist of sandstone, shale and limestone, respectively. The petrography and geochemical analysis conducted to evaluate provenance of siliciclastic deposits in order to understand the paleogeography of Central Iran during the Early Paleozoic time. This study shows that quartz and K-feldspar are the m...

Three magnetic components have been isolated in Ordovician formations of the Yangtze Paraplatform (South China Block). Two of these (Daqing A and Hongshiya B components) yield paleopoles that conform to the Carboniferous to Triassic segment of the apparent polar w•der path for South China, and are therefore interpreted as remagnetizations. The third component (declination/inclination = 30!ø/+66...

Upper Ordovician shallow marine fine-grained sandstones and siltstones exposed in the Loděnice – vinice locality yielded a distinct well-preserved tiering pattern of trace fossils. The two uppermost tiers are composed mainly Bifungites Nereites. Deeper sediment, dominated by Thalassinoides, Zoophycos Teichichnus occur. Most succession is completely bioturbated; however, several storm layers ena...

for the first time, an assemblage of cryptospores, which includes 10 species belonging to nine genera, from the upper ordovicianstrata, is being reported, in iran. these cryptospore assemblages were recovered from the upper part of ghelli formation., from theeastern alborz mountain range. these peri-gondwanan cryptospores have been classified based on their morphology (monad, truedyad, pseudody...

The distinctive, branched thrombolite, Favosamaceria cooperi new group and form, is found widely in the Great Basin, USA, where it is restricted to the Late Cambrian Saukia trilobite Zone. This thrombolite is distinguished by a hedgerow, mazelike organization of ridges similar to garden walls (maceriae) in plan view, branching of ridges into daughter ridges and columns, the polymorphic nature o...