based on the study of brachiopods and conodents a stratigraphic and relative age determination research has been worked out on the paleozoic sediments, located in south of bojnod,northeas of iran.for the first time the sediments of upper ordevician have been recognized in iran, based on some index fossils of brachiopods and conodonts. fourteen species of upper ordovician brachiopods and 12 spec...

Marine redox conditions and their dynamic changes were a major factor that controlled the formation of black shale caused late Ordovician marine extinction in Upper Yangtze Basin (South China). However, spatiotemporal variation potential controlling factors this area remain unclear. We analyzed whole-rock geochemistry pyrite sulfur isotopes ( ? 34 S py ) 47 samples from Late Katian to Rhuddania...

The Aiguilles-Rouges and Mont-Blanc massifs represent a segment of crustal-scale transpressional shear zone named the East Variscan Shear Zone (EVSZ) along which two plutonic pulses occurred during Early Late Carboniferous times. aim this study is to constrain relationships between dynamics zone, mechanisms pluton emplacement at different structural levels within crust magma sources. A detailed...

Abstract Amalgamation of the Yangtze and Cathaysia blocks in context Gondwana assembly early Paleozoic has been addressed for decades, but far-field effects on Block during amalgamation remain unclear. In this study, we outline sequence stratigraphic framework Ordovician succession central-upper analyze provenance records sandstone compositions, distributions, detritus zircon U-Pb dating. The i...

Tarim Basin is a large, superimposed basin rich in petroleum resources, which has experienced many stages of complex tectonic-sedimentary evolution. As the basic geological study Basin, proto-type and tectono-paleogeographic evolution are great significance for understanding distribution reservoirs provide tectonic background theoretical guidance exploration. According to residual thickness map...