FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W2774156687> ?p ?o ?g. }

• W2774156687 endingPage "235" @default.
• W2774156687 startingPage "218" @default.
• W2774156687 abstract "The hematite- and manganese-rich Hotazel iron formation, Griqualand West basin, South Africa, was deposited at a key moment in time, close to the GOE between 2.4 and 2.3 Ga. It stratigraphically overlies the Ongeluk Formation, comprising thick flood basalts, which in turn interfinger with and cover the Makganyene Formation diamictites, the inferred remnants of the first Paleoproterozoic Snowball Earth interval. No extensive research has been conducted to date on the basal part of the Hotazel Formation due to poor exposure, though it constitutes an important link between a period of large-scale ice cover, extensive volcanism and the onset of atmospheric oxygenation. Here, we present a detailed petrographic, geochemical and Fe isotope study of a roughly 3-metre-long drill-core exposing the Ongeluk to Hotazel contact. Our results show that after the cessation of Ongeluk volcanism, primary precipitation of Fe(III) oxyhydroxides from the photic surface zone of the original basin became the dominant sedimentation mechanism. Negative δ56Fe values (between −0.26 and −0.50‰) in micro-drilled hematite-rich chert indicate that surface water δ56Fe compositions at the time of deposition were depleted. Yet, δ56Fe and bulk-rock Fe/Mn values are still substantially higher (1–2‰) than those reported higher up in the Mn-rich layers of the Hotazel sequence, suggesting that redox potentials were still comparatively limited during the earliest stages of the Hotazel depositional environment. The base of the Hotazel Formation thus forms a transitional interval between precipitation from essentially ferruginous seawater, as recorded in the Ghaap Group BIFs, and from isotopically and chemically highly evolved surface waters, as demonstrated by the Hotazel Mn-rich layers. In the absence of Fe(II) as a strong reducing agent, large volumes of photosynthetic oxygen may have eventually escaped into the atmosphere, leading to the onset of atmospheric oxygenation. Our results thus contradict previous models that place the onset of the GOE before the Hotazel Formation, concurrent with and mechanistically linked to the Makganyene and Ongeluk events. Instead, we show that the Hotazel basal sediments are still pre-GOE, consistent with their circa 2.4 Ga age and the continuation of MIF-S higher in the stratigraphic record." @default.
• W2774156687 created "2017-12-22" @default.
• W2774156687 creator A5015546187 @default.
• W2774156687 creator A5051839794 @default.
• W2774156687 creator A5079497543 @default.
• W2774156687 creator A5079709882 @default.
• W2774156687 date "2018-02-01" @default.
• W2774156687 modified "2023-09-23" @default.
• W2774156687 title "Fe isotopes of a 2.4 Ga hematite-rich IF constrain marine redox conditions around the GOE" @default.
• W2774156687 cites W1129004991 @default.
• W2774156687 cites W1631820701 @default.
• W2774156687 cites W1697222721 @default.
• W2774156687 cites W1795469543 @default.
• W2774156687 cites W1965478052 @default.
• W2774156687 cites W1965879393 @default.
• W2774156687 cites W1967509775 @default.
• W2774156687 cites W1968486409 @default.
• W2774156687 cites W1971622854 @default.
• W2774156687 cites W1974024444 @default.
• W2774156687 cites W1974709242 @default.
• W2774156687 cites W1976455066 @default.
• W2774156687 cites W1978052340 @default.
• W2774156687 cites W1979645008 @default.
• W2774156687 cites W1980270634 @default.
• W2774156687 cites W1982842759 @default.
• W2774156687 cites W1984055345 @default.
• W2774156687 cites W1984854172 @default.
• W2774156687 cites W1990103470 @default.
• W2774156687 cites W1991485769 @default.
• W2774156687 cites W1992336857 @default.
• W2774156687 cites W1994109027 @default.
• W2774156687 cites W1994212233 @default.
• W2774156687 cites W1995194566 @default.
• W2774156687 cites W1997958287 @default.
• W2774156687 cites W1998680662 @default.
• W2774156687 cites W1998689216 @default.
• W2774156687 cites W1999845220 @default.
• W2774156687 cites W2006137489 @default.
• W2774156687 cites W2007936777 @default.
• W2774156687 cites W2009888423 @default.
• W2774156687 cites W2011045324 @default.
• W2774156687 cites W2011801766 @default.
• W2774156687 cites W2014523333 @default.
• W2774156687 cites W2015087433 @default.
• W2774156687 cites W2015159257 @default.
• W2774156687 cites W2026969022 @default.
• W2774156687 cites W2027143279 @default.
• W2774156687 cites W2027228820 @default.
• W2774156687 cites W2029036036 @default.
• W2774156687 cites W2030640705 @default.
• W2774156687 cites W2030996811 @default.
• W2774156687 cites W2031100729 @default.
• W2774156687 cites W2034914622 @default.
• W2774156687 cites W2035866696 @default.
• W2774156687 cites W2040046519 @default.
• W2774156687 cites W2042750907 @default.
• W2774156687 cites W2042760382 @default.
• W2774156687 cites W2045036940 @default.
• W2774156687 cites W2045993238 @default.
• W2774156687 cites W2047397895 @default.
• W2774156687 cites W2051614816 @default.
• W2774156687 cites W2052099565 @default.
• W2774156687 cites W2052989634 @default.
• W2774156687 cites W2054861741 @default.
• W2774156687 cites W2061338944 @default.
• W2774156687 cites W2062900030 @default.
• W2774156687 cites W2065565116 @default.
• W2774156687 cites W2067413419 @default.
• W2774156687 cites W2068596469 @default.
• W2774156687 cites W2070396519 @default.
• W2774156687 cites W2070567272 @default.
• W2774156687 cites W2071069131 @default.
• W2774156687 cites W2071172756 @default.
• W2774156687 cites W2073715954 @default.
• W2774156687 cites W2074797379 @default.
• W2774156687 cites W2076647823 @default.
• W2774156687 cites W2078602930 @default.
• W2774156687 cites W2079758306 @default.
• W2774156687 cites W2080043646 @default.
• W2774156687 cites W2080860526 @default.
• W2774156687 cites W2081383679 @default.
• W2774156687 cites W2081641920 @default.
• W2774156687 cites W2084148137 @default.
• W2774156687 cites W2085234182 @default.
• W2774156687 cites W2086410742 @default.
• W2774156687 cites W2087015872 @default.
• W2774156687 cites W2087116257 @default.
• W2774156687 cites W2090027771 @default.
• W2774156687 cites W2090076848 @default.
• W2774156687 cites W2090249305 @default.
• W2774156687 cites W2090903612 @default.
• W2774156687 cites W2091794361 @default.
• W2774156687 cites W2092802537 @default.
• W2774156687 cites W2097391572 @default.
• W2774156687 cites W2101619099 @default.
• W2774156687 cites W2107109600 @default.
• W2774156687 cites W2107297476 @default.
• W2774156687 cites W2107485853 @default.

• next