Interglacial dust, ocean fertilisation and Neoproterozoic earth oxygenation DOI Creative Commons
Leandro G. DaSilva, Peir K. Pufahl, Noël P. James

и другие.

The Depositional Record, Год журнала: 2024, Номер unknown

Опубликована: Ноя. 29, 2024

Abstract Feedback processes that drove Earth's second major increase in ocean–atmosphere oxygen levels during the Neoproterozoic are poorly constrained. Variability seawater redox over geological timescales is commonly linked to changes biogeochemical cycling of P and thus rate primary production generation photosynthetic oxygen. In modern surface ocean, an important source bioessential micronutrients (Fe, Cu, Co, Zn, Mo, Cr Ni) aeolian dust derived from deserts arid, post‐glacial landscapes. It interpreted herein glacial retreat following Sturtian ( ca 717 660 Ma) Marinoan 650 635 snowball glaciations provided copious global ocean. Correlation interglacial siltstone successions palaeogeographical context suggests such accumulation was diachronous concentrated palaeo‐horse latitudes (30° N 30° S). Delivery this continents likely reflected steep radiogenic Sr isotope values 87 Sr/ 86 Sr) post‐Sturtian carbonates, δ 18 O signatures Cryogenian zircons subducted marine sediments. Accumulation sedimentary organic matter also peaked periods, suggesting a causal link between glaciation, production. This relationship implies windblown for evolving biological pump stimulated production, enhanced burial carbon increased concentrations. Thus, delivery ocean critical sustaining Sequestration atmospheric CO 2 organic‐rich siltstones shales have been negative feedback process, which together with silicate weathering, prevented runaway greenhouse conditions periods. The produced by may helped pave way evolution multicellular animals Ediacaran.

Язык: Английский

Conodont diversity, biostratigraphy, and environmental dynamics: Unravelling the Smithian-Spathian transition at Guryul Ravine, Kashmir DOI Creative Commons
Marc Leu, Morgane Brosse, Aymon Baud

и другие.

Gondwana Research, Год журнала: 2025, Номер unknown

Опубликована: Апрель 1, 2025

Язык: Английский

Процитировано

0

Evolution and extinction in a supercontinental world: did the breakup of Rodinia provide metazoans with evolutionary salvation? DOI Creative Commons
P. S. Plummer

Australian Journal of Earth Sciences, Год журнала: 2024, Номер 71(6), С. 821 - 831

Опубликована: Июнь 19, 2024

A time discrepancy of at least 200–300 million years exists between the generally accepted onset metazoan evolution as currently evidenced from fossils compared with that studies molecular level. That temporal disparity coincides existence and subsequent breakup Rodinia Supercontinent when earliest evolutionary crucibles were isolated intracratonic basins rather than globally connected shallow seaways eras. However, discovery fossil evidence to complement extrapolations data has been, continues be, hampered, by both geographical limitations these fact any such would conflict global geological mindset macrofossils age do not exist. Yet recently identified within Amadeus Basin central Australia is a suite macroscopic dates ca 850–840 Ma, exemplifying an early attempt animal restrictions Supercontinent. Such crucibles, however, was extremely vulnerable variations in climatic conditions, which threatened total extinction because isolation limited distribution denying them possibility migrating safer havens. The suggests perhaps comprised cycles about 10 flourished followed climate change induced void 50 100 years. possibly characterised until broke-up, after connections smaller oceans, seas narrow waterways provided life passageway sanctuary during times environmental stress. As just one number Rodinian-aged basins, it likely similar metazoans are preserved elsewhere awaiting discovery.

Язык: Английский

Процитировано

2

Three pulses of breaths toward three evolutionary shifts DOI Creative Commons
Carolina Ortiz‐Guerrero

Communications Earth & Environment, Год журнала: 2024, Номер 5(1)

Опубликована: Март 29, 2024

Oxygen levels in the ocean increased three times between early Ediacaran and Cambrian, synchrony with major developments animal evolution.

Язык: Английский

Процитировано

0

Interglacial dust, ocean fertilisation and Neoproterozoic earth oxygenation DOI Creative Commons
Leandro G. DaSilva, Peir K. Pufahl, Noël P. James

и другие.

The Depositional Record, Год журнала: 2024, Номер unknown

Опубликована: Ноя. 29, 2024

Abstract Feedback processes that drove Earth's second major increase in ocean–atmosphere oxygen levels during the Neoproterozoic are poorly constrained. Variability seawater redox over geological timescales is commonly linked to changes biogeochemical cycling of P and thus rate primary production generation photosynthetic oxygen. In modern surface ocean, an important source bioessential micronutrients (Fe, Cu, Co, Zn, Mo, Cr Ni) aeolian dust derived from deserts arid, post‐glacial landscapes. It interpreted herein glacial retreat following Sturtian ( ca 717 660 Ma) Marinoan 650 635 snowball glaciations provided copious global ocean. Correlation interglacial siltstone successions palaeogeographical context suggests such accumulation was diachronous concentrated palaeo‐horse latitudes (30° N 30° S). Delivery this continents likely reflected steep radiogenic Sr isotope values 87 Sr/ 86 Sr) post‐Sturtian carbonates, δ 18 O signatures Cryogenian zircons subducted marine sediments. Accumulation sedimentary organic matter also peaked periods, suggesting a causal link between glaciation, production. This relationship implies windblown for evolving biological pump stimulated production, enhanced burial carbon increased concentrations. Thus, delivery ocean critical sustaining Sequestration atmospheric CO 2 organic‐rich siltstones shales have been negative feedback process, which together with silicate weathering, prevented runaway greenhouse conditions periods. The produced by may helped pave way evolution multicellular animals Ediacaran.

Язык: Английский

Процитировано

0