Bortoluzzi, G Romeo, T La Cono, V La Spada, G Smedile, F Esposito, V Sabatino, G Di Bella, M Canese, S Scotti, G
...
Published in
Geobiology
Ammonium- and Fe(II)-rich fluid flows, known from deep-sea hydrothermal systems, have been extensively studied in the last decades and are considered as sites with high microbial diversity and activity. Their shallow-submarine counterparts, despite their easier accessibility, have so far been under-investigated, and as a consequence, much less is k...
Schinteie, R Brocks, J J
Published in
Geobiology
While numerous studies have examined modern hypersaline ecosystems, their equivalents in the geologic past, particularly in the Precambrian, are poorly understood. In this study, biomarkers from ~820 million year (Ma)-old evaporites from the Gillen Formation of the mid-Neoproterozoic Bitter Springs Group, central Australia, are investigated to eluc...
Zerkle, A L Mikhail, S
Published in
Geobiology
Nitrogen forms an integral part of the main building blocks of life, including DNA, RNA, and proteins. N2 is the dominant gas in Earth's atmosphere, and nitrogen is stored in all of Earth's geological reservoirs, including the crust, the mantle, and the core. As such, nitrogen geochemistry is fundamental to the evolution of planet Earth and the lif...
Babechuk, M G Kleinhanns, I C Schoenberg, R
Published in
Geobiology
Fractionation of stable Cr isotopes has been measured in Archaean paleosols and marine sedimentary rocks and interpreted to record the terrestrial oxidation of Cr(III) to Cr(VI), providing possible indirect evidence for the emergence of oxygenic photosynthesis. However, these fractionations occur amidst evidence from other geochemical proxies for a...
Shih, P M Hemp, J Ward, L M Matzke, N J Fischer, W W
Published in
Geobiology
The rise of oxygen ca. 2.3 billion years ago (Ga) is the most distinct environmental transition in Earth history. This event was enabled by the evolution of oxygenic photosynthesis in the ancestors of Cyanobacteria. However, long-standing questions concern the evolutionary timing of this metabolism, with conflicting answers spanning more than one b...
Lindsay, M R Anderson, C Fox, N Scofield, G Allen, J Anderson, E Bueter, L Poudel, S Sutherland, K Munson-McGee, J H
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Published in
Geobiology
A railroad causeway across Great Salt Lake, Utah (GSL), has restricted water flow since its construction in 1959, resulting in a more saline North Arm (NA; 24%-31% salinity) and a less saline South Arm (SA; 11%-14% salinity). Here, we characterized microbial carbonates collected from the SA and the NA to evaluate the effect of increased salinity on...
Monteverde, D R Gómez-Consarnau, L Suffridge, C Sañudo-Wilhelmy, S A
Published in
Geobiology
Coenzymes are essential across all domains of life. B vitamins (B1 -thiamin, B2 -riboflavin, B3 -niacin, B5 -pantothenate, B6 -pyridoxine, B7 -biotin, and B12 -cobalamin) represent the largest class of coenzymes, which participate in a diverse set of reactions including C1 -rearrangements, DNA repair, electron transfer, and fatty acid synthesis. B ...
Wang, X L Planavsky, N J Hull, P M Tripati, A E Zou, H J Elder, L Henehan, M
Published in
Geobiology
The chromium isotope system (53 Cr/52 Cr expressed as δ53 Cr relative to NIST SRM 979) is potentially a powerful proxy for the redox state of the ocean-atmosphere system, but a lack of temporally continuous, well-calibrated archives has limited its application to date. Marine carbonates could potentially serve as a common and continuous Cr isotope ...
Estes, E R Andeer, P F Nordlund, D Wankel, S D Hansel, C M
Published in
Geobiology
Manganese (Mn) oxides participate in a range of interactions with organic carbon (OC) that can lead to either carbon degradation or preservation. Here, we examine the abundance and composition of OC associated with biogenic and environmental Mn oxides to elucidate the role of Mn oxides as a reservoir for carbon and their potential for selective par...
Babechuk, M G Kleinhanns, I C Schoenberg, R
Published in
Geobiology
Fractionation of stable Cr isotopes has been measured in Archaean paleosols and marine sedimentary rocks and interpreted to record the terrestrial oxidation of Cr(III) to Cr(VI), providing possible indirect evidence for the emergence of oxygenic photosynthesis. However, these fractionations occur amidst evidence from other geochemical proxies for a...
