An oxygen-rich atmosphere is essential for complex animals. The early Earth had an anoxic
atmosphere, and understanding the rise and maintenance of high O2 levels is critical for …

Although Ce anomalies are commonly used to reconstruct past seawater redox conditions,
published interpretations are based on various proxy materials and analytical approaches …

The theoretical framework of Unconventional Petroleum Geology has been gradually
established along with the rapid progresses in exploration and development of …

Oceanic anoxia—including euxinic settings defined by the presence of water column
hydrogen sulfide (H2S)—is minor in the ocean today. Such conditions, however, were …

Shallow-water carbonate sediments constitute one of the most abundant and widely used
archives of Earth's surface evolution. One of the main limitations of this archive is the …

Abstract The Late Ordovician mass extinction (LOME, ca. 445 Ma) was the first of the “Big
Five” Phanerozoic extinction events and comprised two extinction pulses. Proposed kill …

Expanded ocean anoxia and global cooling have been invoked as major causal
mechanisms for the Late Ordovician mass extinction, but the factors underpinning the …

The speciation of iron in sediments and sedimentary rocks is a widely used proxy for the
chemistry and oxidation state of ancient water bodies. Specifically, the fraction of reactive …

The extent to which Paleozoic oceans differed from Neoproterozoic oceans and the causal
relationship between biological evolution and changing environmental conditions are …

Widespread marine anoxia is hypothesized as the trigger for the second pulse of the Late
Ordovician (Hirnantian) mass extinction based on lithologic and geochemical proxies that …