An early diagenetic deglacial origin for basal Ediacaran “cap dolostones”

Are basal Ediacaran (635 Ma) post-glacial “cap dolostones” diachronous?

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 Cryogenian snowball Earth. The dolostone has a global average thickness of 18.5 m and is interpreted stratigraphically in different ways in the current literature: as diachronous (top and bottom) and tracking glacioeu...

Germanium/silica ratios in diagenetic chert nodules from the Ediacaran Doushantuo Formation, South China

Composition of Some Smectites and Diagenetic Illitic Clays and Implications for Their Origin

-Chemical analysis by X-ray fluorescence (XRF) and calculated structural formulae of clay-size fractions of smectites from Cretaceous bentonites and illitic clays from Cretaceous, Devonian, and Ordovician bentonites and Jurassic and Permian sandstones indicate the nature and extent of various types of ionic substitution. The determination of tetrahedral (A1, Si) and octahedral (A1, Mg, Fe) comp...

Thallium isotopes in early diagenetic pyrite – A paleoredox proxy?

This paper presents the first study of Tl isotopes in early diagenetic pyrite. Measurements from two sections deposited during the Toarcian Ocean Anoxic Event (T-OAE, 183 Ma) are compared with data from Late Neogene (<10 Ma) pyrite samples from ODP legs 165 and 167 that were deposited in relatively oxic marine environments. The Tl isotope compositions of Late Neogene pyrites are all significant...

Rapid deglacial and early Holocene expansion of peatlands in Alaska.

Northern peatlands represent one of the largest biospheric carbon (C) reservoirs; however, the role of peatlands in the global carbon cycle remains intensely debated, owing in part to the paucity of detailed regional datasets and the complexity of the role of climate, ecosystem processes, and environmental factors in controlling peatland C dynamics. Here we used detailed C accumulation data fro...