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 Gucheng region is oil and gas accumulation area of Tarim Basin，dominated by beach controlled lithologic reservoirs，which has superior conditions broad exploration prospects. lower Paleozoic strata in the are Carboniferous, Ordovician, Cambrian systems from top to bottom. Silurian, Devonian, Permian missing. Ordovician – main target layers area. There four reservoirs: group, Yingshan Penglai...

The Ordovician biodiversification is considered one of the most significant radiations in marine ecosystems entire Phanerozoic. Originally recognized as ‘Ordovician Radiation’, a label retained during 1980s and 1990s, term ‘Great Biodiversification Event’ (GOBE) was coined late 1990s subsequently adopted by scientific community. biodiversification, has always been long-term adaptive radiation, ...

Silurian outcrops, not previously recorded from central Texas, have been identified from the Llano uplift, where they occur in collapse structures within the Lower Ordovician Honeycut Formation of the Ellenburger Group. The formation is a pinkish-gray granular limestone, contains fossils of probable Wenlock age, and is named the Starcke Limestone.

U–Pb ages were obtained on single detrital zircon grains separated from six samples of Neoproterozoic and Lower Palaeozoic sedimentary and volcanosedimentary rocks from NW Iberia using the laser ablation microprobe-inductively coupled plasma mass spectrometry (LAM-ICP-MS) method. Precambrian greywackes yielded abundant zircons with Neoproterozoic (800–640 Ma) and Mesoproterozoic (0.9–1.2 Ga) ag...

The strata in the Shita Mountain, Yunkai region, are predominantly composed of clastic rocks with intercalated limestones. However, precise stratigraphic age remains uncertain due to scarcity fossils. Previously, conglomerate layers this region were considered indicative Yunan Orogeny during Cambrian–Ordovician transition. through identification 12 lithofacies types and 5 combinations Mountain ...

Abstract Cyclostratigraphy is an important tool for understanding astronomical climate forcing and reconstructing geological time in sedimentary sequences, provided that imprint of insolation variations caused by Earth's orbital eccentricity, obliquity precession preserved (Milankovitch forcing). Understanding has proven fundamental the study Cenozoic systems construction high-resolution contin...