Geochimica et Cosmochimica Acta

We performed a series of low temperature hydrothermal alteration experiments using the highly primitive CO3.00 chondrite DOM 08006 as the protolith to investigate aqueous alteration conditions on carbonaceous planetesimals. Our experiments employed a range of water-to-rock (W/R) ratios by mass (0.2, 0.4, 1.0) and a heating duration of 100 days at 80°C. We also used a short-duration experiment ter…

Chemical weathering of silicate rocks is a fundamental control on the carbon cycle, although on timescales shorter than a few tens of kyr, transient carbon storage becomes more important. However, weathering can still act as an amplifier or inhibitor of the carbon cycle on these timescales. Further, weathering produces soils, a storage reservoir of carbon, although the rate at which soils can be …

Microfossil-bearing black cherts from the ca. 3.4 Ga Strelley Pool Formation in the Goldsworthy Greenstone Belt, Pilbara Craton, offer critical insights into early Archean microbial ecosystems. In this study, we analyzed concentric colloform pyrite grains in these cherts to investigate their formation mechanisms and potential microbial involvement. The examined chert samples contain abundant orga…

Estimating the sulfur isotope composition of Earth’s fertile mantle can provide insight into Earth’s constitution and the processes associated with establishing its highly siderophile element abundances. There is currently a disagreement in sulfur isotopic compositions between Ocean Island Basalts (OIB) (δ 34 S = 0) and Mid-Ocean Ridge Basalts (MORB) (δ 34 S ≈ −1) implying that their mantle sourc…

Many of the East African Rift Valley lakes are soda lakes that have attracted considerable research interest over the last decades with a focus on their extraordinarily high bioproductivity, high concentration of dissolved organic carbon (DOC), and diverse microbial communities. Yet, the distribution of trace metals, particularly dissolved rare earth elements (REE) and yttrium in these soda lake …