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Are basal Ediacaran (635 Ma) post-glacial “cap dolostones” diachronous?
Abstract A layer of shallow-water dolostone (“cap dolostone”) with idiosyncratic sedimentary structures was deposited across continental margins world-wide in the aftermath of the terminal CryogenianExpand
An emerging picture of Neoproterozoic ocean chemistry: Insights from the Chuar Group, Grand Canyon, USA
Abstract Detailed iron, sulfur and carbon chemistry through the > 742 million year old Chuar Group reveals a marine basin dominated by anoxic and ferrous iron-rich (ferruginous) bottom watersExpand
Dominant eukaryotic export production during ocean anoxic events reflects the importance of recycled NH4+
It is proposed that new production during OAE 2 primarily was driven by direct -assimilation supplemented by diazotrophy, whereas chemocline denitrification and anammox quantitatively consumed and a marine nitrogen reservoir dominated by , could lead to eukaryotic biomass depleted in 15N. Expand
Volcanic–plutonic parity and the differentiation of the continental crust
In both tectonic settings, the results indicate that fractional crystallization, rather than crustal melting, is predominantly responsible for the production of intermediate and felsic magmas, emphasizing the role of mafic cumulates as a residue of crustal differentiation. Expand
A syn‐depositional age for Earth’s deepest δ13C excursion required by isotope conglomerate tests
Terra Nova, 24, 318–325, 2012 Abstract The most negative carbon isotope excursion in Earth history is found in carbonate rocks of the Ediacaran Period (635–542 Ma). Workers have interpretedExpand
Sediment cycling on continental and oceanic crust
Sedimentary rocks are often described as declining in quantity with increasing age due to the cumulative effects of crustal deformation and erosion. One important implication of such a model is thatExpand
Constraints on the origin and relative timing of the Trezona δ13C anomaly below the end-Cryogenian glaciation
Abstract The Neoproterozoic Era was punctuated by the ‘Sturtian’ (~ 710 million years ago) and ‘Marinoan’ (~ 635 million years ago) low-latitude glaciations. Carbonates preceding the younger MarinoanExpand
The rise and fall of stromatolites in shallow marine environments
Stromatolites are abundant in shallow marine sediments deposited before the evolution of animals, but in the modern ocean they are restricted to locations where the activity of animals is limited.Expand
Ca and Mg isotope constraints on the origin of Earth's deepest δ13C excursion
Abstract Understanding the extreme carbon isotope excursions found in carbonate rocks of the Ediacaran Period (635–541 Ma), where δ 13 C of marine carbonates ( δ 13 C carb ) reach their minimum ( -Expand
Chemostratigraphic and U–Pb geochronologic constraints on carbon cycling across the Silurian–Devonian boundary
Abstract The Devonian Period hosts extraordinary changes to Earth's biosphere. Land plants began their rise to prominence, with early vascular vegetation beginning its colonization of near-shoreExpand