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The snowball Earth hypothesis: testing the limits of global change
The gradual discovery that late Neoproterozoic ice sheets extended to sea level near the equator poses a palaeoenvironmental conundrum. Was the Earth’s orbital obliquity > 60� (making the tropicsExpand
The oxygen isotopic composition of seawater during the Last Glacial Maximum
High-resolution oxygen and hydrogen isotope measurements were made on pore fluids from deep-sea sediments from sites in the North and South Atlantic. The data provide direct measurements of changesExpand
Large Perturbations of the Carbon Cycle During Recovery from the End-Permian Extinction
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 anExpand
The Salinity, Temperature, and δ18O of the Glacial Deep Ocean
We use pore fluid measurements of the chloride concentration and the oxygen isotopic composition from Ocean Drilling Program cores to reconstruct salinity and temperature of the deep ocean during theExpand
Pore Fluid Constraints on the Temperature and Oxygen Isotopic Composition of the Glacial Ocean
Pore fluids from the upper 60 meters of sediment 3000 meters below the surface of the tropical Atlantic indicate that the oxygen isotopic composition (δ18O) of seawater at this site during the lastExpand
Toward a Neoproterozoic composite carbon-isotope record
Glacial deposits of Sturtian and Marinoan age occur in the well-studied Neoproterozoic successions of northern Namibia, South Australia, and northwestern Canada. In all three regions, the MarinoanExpand
13 C- 18 O bonds in carbonate minerals: A new kind of paleothermometer
The abundance of the doubly substituted CO2 isotopologue, 13 C 18 O 16 O, in CO2 produced by phosphoric acid digestion of synthetic, inorganic calcite and natural, biogenic aragonite is proportionalExpand
Defining an absolute reference frame for 'clumped' isotope studies of CO 2
We present a revised approach for standardizing and reporting analyses of multiply substituted isotopologues of CO2 (i.e., ‘clumped’ isotopic species, especially the mass-47 isotopologues). OurExpand
Heterotrophic Archaea dominate sedimentary subsurface ecosystems off Peru.
It is shown that extractable archaeal rRNA, selecting only for active community members in these ecosystems, is dominated by sequences of uncultivated Archaea affiliated with the Marine Benthic Group B and the Miscellaneous Crenarchaeotal Group, whereas known methanotrophic Archaea are not detectable. Expand
New views of tropical paleoclimates from corals
Abstract Corals offer a rich archive of past climate variability in tropical ocean regions where instrumental data are limited and where our knowledge of multi-decadal climate sensitivity isExpand