Premium
Stratified oceans and oxygenation of the late Precambrian environment: a post glacial geochemical record from the Neoproterozoic of W. Mongolia
Author(s) -
Shields Graham,
Stille Peter,
Brasier Martin D.,
Atudorei NicuViorel
Publication year - 1997
Publication title -
terra nova
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.353
H-Index - 89
eISSN - 1365-3121
pISSN - 0954-4879
DOI - 10.1111/j.1365-3121.1997.tb00016.x
Subject(s) - precambrian , geology , glacial period , diagenesis , paleontology , stratification (seeds) , ecological succession , tectonics , oceanography , geochemistry , earth science , ecology , botany , germination , dormancy , biology , seed dormancy
The late Neoproterozoic (750–545 Ma) was a time of revolutionary environmental change, recurrent glaciation and tectonic upheaval, which culminated in the evolution of metazoans and animal biomineralization. Geochemical data are presented for a post glacial (∼ 700 Ma) limestone succession from W. Mongolia. 87 Sr/ 86 Sr is used to constrain the timing of early diagenetic exchange. Stratigraphic trends to high δ 13 C (carb) ) and δ 13 C (org) mirror sea‐level fluctuations, which, we argue, is consistent with the hypothesis that late Precambrian ocean chemistry, was controlled by vertical stratification. Repeated establishment of stratification 700–545 Ma would have led to greater oxygen availability in the surface environment. A causal link between this oxygenation and the further evolution of animals is proposed.