University of Tasmania
Browse

File(s) under permanent embargo

Four cycles of oxygenation in the phanerozoic

conference contribution
posted on 2023-05-24, 13:47 authored by Ross LargeRoss Large, Jacqueline HalpinJacqueline Halpin, Leonid Danyushevsky, Maslennikov, VV, Stuart BullStuart Bull, Gregory, D, Lyons, TW, Elena LounejevaElena Lounejeva
Sedimentary pyrite captures trace elements (TE) from the oceans and tracks variations in their seawater concentrations through time [1]. LA-ICPMS analysis of sedimentary pyrites, based on newly developed standards, has enabled the development of temporal ocean concentration curves for 22 TE [2].
   Our results show that TE variations over the last 700 million years of ocean history have been strongly cyclical. We interpret these cycles to indicate that the Late Neoproterozoic to Phanerozoic oceans went through dramatic changes in mean oxygen content. Four major cycles are recognised: Late Cryogenian to Late Ordovician, Early Silurian to late Devonian, Early Carboniferous to Late Permian and Triassic to Quaternary. Oxygen maxima, indicated by Se, U and Mo proxies, occur at 540, 390, 310 and 0 Ma, supporting previous models [3, 4]. Oxygen minima, indicated by trace element drawdown, occur at 700, 455, 365 and 200 Ma. Extended periods of low oxygen in the oceans have led to extreme deficiency of some elements that are critical for life. The periods of extreme Se depletion coincide with the mass extinction events at end Ordovician, Late Devonian and the Triassic-Jurassic boundary, suggesting that Se-deficiency in the oceans may be a contributing cause of marine mass extinctions.

History

Publication title

Mineralogical Magazine: Goldschmidt 2013 Abstracts

Volume

77

Pagination

1546

ISSN

0026-461X

Department/School

School of Natural Sciences

Event title

Goldschmidt 2013

Event Venue

Florence, Italy

Date of Event (Start Date)

2013-08-25

Date of Event (End Date)

2013-08-30

Repository Status

  • Restricted

Socio-economic Objectives

Expanding knowledge in the earth sciences

Usage metrics

    University Of Tasmania

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC