Carbon isotopic evidence for rapid methane clathrate release recorded in coals at the terminus of the Late Palaeozoic Ice Age.

The end of the Late Palaeozoic Ice Age (LPIA) ushered in a period of significant change in Earth's carbon cycle, demonstrated by the widespread occurrence of coals worldwide. In this study, we present stratigraphically constrained organic stable carbon isotope (δC) data for Early Permian coals (312 vitrain samples) from the Moatize Basin, Mozambique, which record the transition from global icehouse to greenhouse conditions. These coals exhibit a three-stage evolution in atmospheric δC from the Artinskian to the Kungurian.

Direct Rubidium-Strontium Dating of Hydrocarbon Charge Using Small Authigenic Illitic Clay Aliquots from the Silurian Bituminous Sandstone in the Tarim Basin, NW China.

Illitic clay is ubiquitous in clastic hydrocarbon reservoirs, and the host for several radiometric isotopes such as the potassium-argon (K-Ar) and rubidium-strontium (Rb-Sr) systems. This study applied the isotope-dilution thermal ionization mass spectrometry technique for small samples (3-4 mg) to conduct illite Rb-Sr isotope dating of five illitic clay samples from the Silurian bituminous sandstone (SBS) intersected by five drillholes in the Tarim Basin, NW China. The Rb/Sr ratio of clays is fractionated mainly by the addition of Rb during the illitization of mixed-layer illite/smectite (I/S), which is the dominant clay species in the Tarim Basin samples.

Methodology to determine the extent of anaerobic digestion, composting and CH oxidation in a landfill environment.

An examination of the processes contributing to the production of landfill greenhouse gas (GHG) emissions is required, as the actual level to which waste degrades anaerobically and aerobically beneath covers has not been differentiated. This paper presents a methodology to distinguish between the rate of anaerobic digestion (r), composting (r) and CH oxidation (r) in a landfill environment, by means of a system of mass balances developed for molecular species (CH, CO) and stable carbon isotopes (δC-CO and δC-CH). The technique was applied at two sampling locations on a sloped area of landfill.

Genome-Centric Analysis of Microbial Populations Enriched by Hydraulic Fracture Fluid Additives in a Coal Bed Methane Production Well.

Coal bed methane (CBM) is generated primarily through the microbial degradation of coal. Despite a limited understanding of the microorganisms responsible for this process, there is significant interest in developing methods to stimulate additional methane production from CBM wells. Physical techniques including hydraulic fracture stimulation are commonly applied to CBM wells, however the effects of specific additives contained in hydraulic fracture fluids on native CBM microbial communities are poorly understood.

Methane metabolism in the archaeal phylum Bathyarchaeota revealed by genome-centric metagenomics.

Methanogenic and methanotrophic archaea play important roles in the global flux of methane. Culture-independent approaches are providing deeper insight into the diversity and evolution of methane-metabolizing microorganisms, but, until now, no compelling evidence has existed for methane metabolism in archaea outside the phylum Euryarchaeota. We performed metagenomic sequencing of a deep aquifer, recovering two near-complete genomes belonging to the archaeal phylum Bathyarchaeota (formerly known as the Miscellaneous Crenarchaeotal Group).

Simultaneous determination of delta33S(V-CDT) and delta34S(V-CDT) using masses 48, 49 and 50 on a continuous flow isotope ratio mass spectrometer.

A new, fast, continuous flow technique is described for the simultaneous determination of delta33S and delta34S using SO masses 48, 49 and 50. Analysis time is approximately 5 min/sample with measurement precision and accuracy better than +/-0.3 per thousand.