This review focuses on the rapidly growing field of natural 238U/235U variability, largely
driven by the technical advances in the measurement of U isotope ratios by mass …

Many currently producing shale-gas reservoirs are overmature oil-prone source rocks.
Through burial and heating these reservoirs evolve from organic-matter-rich mud deposited …

Modern low-oxygen marine systems exhibit patterns of molybdenum–uranium covariation
that can be linked to specific attributes and processes of the depositional system, including …

The distributions of certain minor and trace elements in marine sediments should potentially
provide forensic tools for determining the redox conditions of the bottom waters at the time of …

The black shale submember of core shales of Pennsylvanian Kansas-type cyclothems is
highly enriched in redox-sensitive trace elements (TEs) relative to the overlying gray shale …

Analyses of 21 samples collected from a core of the 52.8-cm-thick Stark Shale Member of
the Dennis Limestone in Wabaunsee County, Kansas, demonstrate four cycles with two …

Recent studies have identified a range of new applications of trace-metal concentration data
in the analysis of paleoceanographic systems. In restricted anoxic marine systems, trace …

Geochemical processes involving living organisms or detrital carbonaceous material have
often been invoked to explain the preferential enrichment of some metallic elements in …

Shales and mudrocks are enriched with diverse suites of major elements and trace metals
that reflect their depositional environment, provenance and diagenesis. Here we present …

The Cretaceous is characterized by unusually widespread distribution of “black shales”--
sequences of variable lithology containing numerous beds with organic-carbon (OC) …