The exceptionally organic-rich rocks of the 1.98 Ga Zaonega Formation deposited in the Onega Basin, NW Russia, have refined our understanding of Earth System evolution during the Paleoproterozoic rise in atmospheric oxygen. These rocks were formed in vent-or seepinfluenced settings contemporaneous with voluminous mafic volcanism and contain strongly 13 C-depleted organic matter. Here we report new isotopic (δ 34 S, Δ 33 S, Δ 36 S, δ 13 Corg) and mineralogical, major element, total sulphur and organic carbon data for the upper part of the Zaonega Formation, which was deposited shortly after the termination of the Lomagundi-Jatuli positive carbon isotope excursion. The data were collected on a recently obtained 102 m drillcore section and show a δ 13 Corg shift from-38‰ to-25‰. Sedimentary sulphides have δ 34 S values typically between +15‰ and +25‰ reflecting closed-system sulphur isotope behaviour
Megalithic cultures of central India provide important links between the southern Neolithic-Chalcolithic cultures and the early Historical period (∼500 BC to ∼AD 700) and reveal knowledge of ancient traditions of early inhabitants. Scientific dating of these Megalithic burial sites is a challenging task due to scarcity of dateable material and alterations. Here, we present multiple accelerator mass spectrometry radiocarbon (AMS 14C) dates from equine tooth-enamel and organic food remains recovered from pots from Megalithic burials of the Vidarbha region. Using δ13CTOC and δ15N values of organic food remains recovered from pots, we deduced past-diet (palaeo-vegetation) that indicates C4 type of vegetation and thus arid climate during life-spans of these burials. We also analyzed stable δ13C and δ18O isotopes of equine tooth-enamel to investigate hydro-climatic conditions of Maharashtra (Vidarbha region). A total of 10 AMS 14C dates of tooth enamel provide a time range of AD 250–874 for two Megalithic burials. Two AMS 14C dates of organic food remains recovered from pots corroborated aforementioned time-range. The average δ13C and δ18O of equine tooth-enamel samples were −5.3 ± 2.1‰ and −2.9 ± 0.8‰, respectively, both significantly enriched compared to their modern counterparts (−13.7‰ ± 0.7 and −4.3‰ ± 1.1), indicating intense arid conditions in the past.
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