The terminal Neoproterozoic Era (850-542 Ma) is characterized by the most pronounced positive sulfur isotope ((34)S/(32)S) excursions in Earth's history, with strong variability and maximum values averaging δ(34)S∼+38‰. These excursions have been mostly interpreted in the framework of steady-state models, in which ocean sulfate concentrations do not fluctuate (that is, sulfate input equals sulf...

line survey has been made to study interstellar 32 S= 34 S and 34 S= 33 S ratios from the galactic disk. The four CS isotopomers were detected in 20 star forming regions with galactocentric distances between 3 and 9 kpc. From a comparison of line velocities, the C 33 S J=2{1 rest frequency is 250 kHz below the value given in the Lovas (1992) catalog. Taking 12 C= 13 C ratios from Wilson & Rood ...

Redox chemistry of the coupled atmosphere–hydrosphere system has coevolved with the biosphere, from global anoxia in the Archean to an oxygenated Proterozoic surface environment. However, to trace these changes to the very beginning of the rock record presents special challenges. All known Eoarchean ( c . 3850–3600 Ma) volcanosedimentary successions (i.e. supracrustal rocks) are restricted to h...

Mass-independent fractionation of sulfur isotopes (S MIF) in Archean and Paleoproterozoic rocks provides strong evidence for an anoxic atmosphere before ~2,400 Ma. However, the origin of this isotopic anomaly remains unclear, as does the identity of the molecules that carried it from the atmosphere to Earth's surface. Irrespective of the origin of S MIF, processes in the biogeochemical sulfur c...

The mass spectrometric analysis of the impact of sulfur dioxide and dust emission on carbon and oxygen stable isotopic compositions of glucose hydrolysed from α-cellulose samples extracted from Scots pine growing in the vicinity of "Huta Katowice" steelworks was the main aim of this study. The annual rings covered the time span from 1975 to 2012 AD. The relationships between climatic conditions...

The environmental expression of sulfur compound disproportionation has been placed between 640 and 1050 million years ago (Ma) and linked to increases in atmospheric oxygen. These arguments have their basis in temporal changes in the magnitude of 34S/32S fractionations between sulfate and sulfide. Here, we present a Proterozoic seawater sulfate isotope record that includes the less abundant sul...