Paleogeographic forcing of the strontium isotopic cycle in the Neoproterozoic
MetadataShow full item record
© 2016 International Association for Gondwana ResearchThe period spanning from 825 to 540 Ma is characterized by major changes in the surficial Earth system. This extraordinary interval starts with the breakup of the Rodinia supercontinent and eruption of a series of large igneous provinces and ends with the assembly of Gondwana, giving rise to the Pan-African orogenies. This paleogeographic reorganization is accompanied by a global climatic cooling, including the paroxysmal Cryogenian “snowball” glacial events. The 87Sr/86Sr of seawater displays a major long-term rise over this interval that is punctuated by episodic, smaller declines and inflections. We use a coupled deep time climate-carbon numerical model to explore the complex role of tectonics and climate on this distinct evolution in seawater 87Sr/86Sr. We show that the modulation of the weathering of the erupted large igneous provinces by continental drift explains the changes in seawater 87Sr/86Sr from 800 to 635 Ma. The subsequent sharp rise in seawater 87Sr/86Sr from 635 to 580 Ma is the result of erosion of radiogenic crust exposed in the Pan-African orogens. Coeval evolution of atmospheric CO2 displays a decrease from about 80 times the pre-industrial level around 800 Ma to 5 times just before the beginning of the Phanerozoic.
Showing items related by title, author, creator and subject.
Dissolution of basalts and peridotite in seawater, in the presence of ligands, and CO2: Implications for mineral sequestration of carbon dioxideWolff-Boenisch, Domenik; Wenau, S.; Gislason, S.; Oelkers, E. (2011)Steady-state silica release rates (rSi) from basaltic glass and crystalline basalt of similar chemical composition as well as dunitic peridotite have been determined in far-from-equilibrium dissolution experiments at 25 ...
Greenalite precipitation linked to the deposition of banded iron formations downslope from a late Archean carbonate platformRasmussen, Birger; Muhling, Janet; Suvorova, A.; Krapež, B. (2017)© 2016 Elsevier B.V.Banded iron formations (BIFs) were deposited as deep-water facies distal to the late Archean Campbellrand carbonate platform, Transvaal Supergroup, South Africa. They are traditionally interpreted to ...
Precipitation of iron silicate nanoparticles in early Precambrian oceans marks Earth’s first iron ageRasmussen, Birger; Krapež, Bryan; Muhling, Janet; Suvorova, A. (2015)The early ocean was characterized by anoxic, iron-rich (ferruginous) conditions before the rise of atmospheric oxygen ~2.45 b.y. ago. A proxy for ferruginous conditions in the ancient ocean is the deposition of banded ...