The northern Namibian Karoo-aged successions are part of a Gondwana-wide sedimentary system emerging at the Carboniferous–Permian boundary and existing for more than 50 Ma. Karoo Supergroup importance in understanding evolution rift system. This study presents new whole-rock geochemical data combined with detrital zircon morphology as well U−Pb ages Lu−Hf composition late Palaeozoic siliciclast...

The evolutionary emergence of animals is one of the most significant episodes in the history of life, but its timing remains poorly constrained. Molecular clocks estimate that animals originated and began diversifying over 100 million years before the first definitive metazoan fossil evidence in the Cambrian. However, closer inspection reveals that clock estimates and the fossil record are less...

Abstract There are current debates around the extent of global ocean oxygenation, particularly from late Neoproterozoic to early Paleozoic, based on analyses various geochemical indices. We present a temporal trend in excess barium (Baexcess) contents marine organic-rich mudrocks (ORMs) provide an independent constraint redox evolution. The absence remarkable Baexcess enrichments Precambrian (&...

The San Emigdio and related Pelona, Orocopia, Rand and Sierra de Salinas schists of southern California were underplated beneath the southern Sierra Nevada batholith and adjacent southern California batholith along a shallow segment of the subducting Farallon plate in Late Cretaceous to early Tertiary time. These subduction accretion assemblages represent a regional, deeply exhumed, shallowly d...

Discovery of fossils of the Ediacara biota near the top of the Spitzkopf Member at farm Swanpunt extends the known range of these remains in Namibia more than 600 m to near the sub-Cambrian unconformity. The fossiliferous beds occur approximately 100 m above a volcanic ash dated at 543 +/- 1 Ma, and thus may be the youngest Proterozoic Ediacara-type fossils reported anywhere in the world. Fossi...

With the targets of petroleum exploration transferred to deep and ancient strata, abundant oil gas resources have been found in Lower Paleozoic older strata central western China. Due complex evolutionary processes including multiple episodes hydrocarbon accumulation ubiquitously accompanied by secondary alterations, significant uncertainties remain concerning generation time these revealed sou...

An unusual richness of biogeochemical events is recorded in Neoproterozoic– Cambrian strata of the Death Valley region, California, United States. Eight negative carbon isotope (d13C) excursions are found in carbonate units between 1.08 Ga and the Precambrian/Cambrian boundary; four of these excursions occur in carbonates that contain textural features similar to those found globally in postgla...

the dalir phosphate horizon is located ~57 km southwest of chalous, mazandaran province. the horizon developed as stratiform within upper shale of soltanieh formation (late neoproterozoic - early cambrian). according to mineralogical data, the major minerals of the phosphate horizon are calcite, fluorapatite, dolomite, quartz, pyrite, muscovite, and illite. microscopic evidence such as existenc...