Evidence for benthic oxygen production in Neoarchean lacustrine stromatolites
نویسندگان
چکیده
Abstract The evolution of oxygenic photosynthesis fundamentally altered the global environment, but history this metabolism prior to Great Oxidation Event (GOE) at ca. 2.4 Ga remains unclear. Increasing evidence suggests that non-marine microbial mats served as localized “oxygen oases” for hundreds millions years before GOE, though direct examination redox proxies in Archean lacustrine deposits relatively limited. We report spatially distinct patterns positive and negative cerium (Ce) anomalies stromatolites from 2.74 Ventersdorp Supergroup (Hartbeesfontein Basin, South Africa), which indicate dynamic conditions within ancient communities were driven by photosynthesis. Petrographic analyses rare earth element signatures support a primary origin Ce stromatolite oxides. Oxides surrounding former bubbles entrained (preserved fenestrae) exhibit anomalies, while oxides laminae typically contain strong anomalies. spatial are most parsimoniously explained oxidation scavenging around oxygen produced mats. Our new data supports presence ~300 m.y. add growing early oases deposits.
منابع مشابه
Plio-pleistocene Lacustrine Stromatolites from Lake Turkana, Kenya: Morphology, Stratigraphy and Stable Isotopes
Abell, P.I., Awramik, S.M., Osborne, R.H. and Tomellini, S., 1982. Plio-Pleistocene lacustrine stromatolites from Lake Turkana, Kenya: morphology, stratigraphy and stable isotopes. Sediment. Geol., 32: 1--26. A sequence of fossil stromatolites from Lake Turkana in Kenya was examined for 51SO and 513C content. These stromatolites, ranging in age from Holocene (~10,000 yrs B.P.) to Middle Pliocen...
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ژورنال
عنوان ژورنال: Geology
سال: 2022
ISSN: ['0091-7613', '1943-2682']
DOI: https://doi.org/10.1130/g49894.1