Daniel P. Schrag

TL;DR: Negative carbon isotope anomalies in carbonate rocks bracketing Neoproterozoic glacial deposits in Namibia, combined with estimates of thermal subsidence history, suggest that biological productivity in the surface ocean collapsed for millions of years.

TL;DR: The recent discovery that late Neoproterozoic ice sheets extended to sea level near the equator poses a palaeoenvironmental conundrum as discussed by the authors, which does not account for major features such as abrupt onsets and terminations of discrete glacial events, their close association with large (> 10&) negative d 13 C shifts in seawater proxies, the deposition of strange carbonate layers (cap carbonates) globally during postglacial sea-level rise, and the return of large sedimentary iron formations.

TL;DR: In this paper, a correlation scheme for the Neoproterozoic that corroborates radiometric data that indicate that there were three glacial epochs between ca. 750 and 580 Ma was proposed.

TL;DR: High-resolution carbon isotope measurements of multiple stratigraphic sections in south China demonstrate that the pronounced carbon isotopic excursion at the Permian-Triassic boundary was not an isolated event but the first in a series of large fluctuations that continued throughout the Early Triassic before ending abruptly early in the Middle Triassic.

TL;DR: In this paper, the authors proposed a carbonate-water paleothermometer, which is a thermodynamic-based approach to carbonate paleometric analysis. But it is not suitable for interpolation and even modest extrapolation, and it is rigorously independent of the d 18 O of water and d 13 C of DIC from which carbonate grew.