Oolitic ironstones are iron-rich and chert-poor sedimentary rocks containing concentrically
coated grains composed of iron (oxyhydr) oxides and iron phyllosilicates that offer a unique …

Estimates for animal antiquity exhibit a significant disconnect between those from molecular
clocks, which indicate crown animals evolved∼ 800 million years ago (Ma), and those from …

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 …

In one form or another, iron speciation has had a long history as a paleoredox proxy. The
technique has been refined considerably over the years, and the most recent scheme is …

Abstract The Devonian–Carboniferous transition marks a fundamental shift in the surface
environment primarily related to changes in ocean–atmosphere oxidation states,, resulting …

Terrestrial and airborne laser scanning and structure from motion techniques have emerged
as viable methods to map snow depths. While these systems have advanced snow …

Pyrite formation in marine sedimentary environments plays a key role in the global
biogeochemical cycles of carbon, sulfur and iron, regulating Earth's surface redox balance …

Continental interiors were flooded by epeiric seas during many intervals of the geologic
past. Few modern analogs exist for these environments, however, and basic variables such …

Abstract The Nonesuch Formation microbiota provide a window into ca. 1075 Ma life within
the interior of ancient North America. The Nonesuch water body formed following the …