The Permian Phosphoria Formation is a reservoir for oil and gas in the western United States, as well as a major source of phosphate. This study examined the relationship between phosphate richness and porosity exhibited in the formation. Petrographic analysis was carried out on rock samples collected from the Phosphoria (Park City) Formation located north of Vernal, Utah, on the southern flank...

The end-Permian extinction event (EPEE) considered to have been caused by the eruption of Siberian Large Igneous Province (SLIP), age which is critical for extinction-SLIP model evaluation. Tunguska Basin flora during this time, in accordance with EPEE model, supposed killed massive injection into atmosphere poisonous substances such as methane, sulfates, mercury and combastion coals. In additi...

The oldest preserved visual systems are to be found in the extinct trilobites, marine euarthropods which existed between about 520 and 250 million years ago. Because they possessed a calcified cuticle, they have a good fossil record, and commonly the lens-bearing surfaces of their paired compound eyes are well preserved. The sublensar structures, however, remain unknown. Three kinds of eyes hav...

Although the status of Crinoidea (sea lilies and featherstars) as sister group to all other living echinoderms is well-established, relationships among crinoids, particularly extant forms, are debated. All living species are currently placed in Articulata, which is generally accepted as the only crinoid group to survive the Permian-Triassic extinction event. Recent classifications have recogniz...

The Permian Lucaogou Formation in the Junggar Basin, NW China is target layer for shale oil exploration, but its hydrocarbon precursors have remained focus of debate. In this study, we investigated source rocks throughout Well J10025 by conducting detailed petrological, paleontological, and geochemical analyses purpose revealing occurrence cyanobacterial blooms as specific events upper Formatio...

A high-resolution chemostratigraphic study of a 24-m-thick section at West Blind Fiord on Ellesmere Island (Canadian Arctic) documents stepwise environmental deterioration in the marine Sverdrup Basin during the late Changhsingian (late Late Permian) as a result of volcanic disturbances to surrounding landmasses. A horizon within the upper Lindström Formation (datum A) is characterized by incre...

The Variscan French Massif Central experienced two successive stages of extension from Middle Carboniferous to Early Permian. In the northern Massif Central, the first stage began in the late Visean, immediately after nappe stacking, and is well recorded by NamurianWestphalian synkinematic plutonism. The Middle Carboniferous leucogranites widespread in the NW Massif Central (Limousin and Sioule...