The geology of the ice-covered interior of the East Antarctic shield is completely unknown; inferences about its composition and history are based on extrapolating scant outcrops from the coast inland. Although the shield is clearly composite in nature, a large part of its interior has been represented by a single Precambrian block—termed the Mawson block—that includes the ArcheanMesoproterozoi...

13 Ž . New records of the abundance of C in marine organic matter have been compiled for i the later Neoproterozoic, from Ž . Ž . Ž . Ž . 800 to 543 Ma 346 analyses , ii the Cambrian through the Jurassic 1616 analyses , and iii the Cretaceous and Cenozoic Ž . 13 2493 analyses . Comparison of these to existing compilations of the abundance of C in sedimentary carbonates has Ž . allowed developme...

The Neoproterozoic Quruqtagh Group in the Tarim Block, NW China, contains multiple diamictites in the Bayisi, Altungol, Tereeken, and Hankalchough formations. These diamictites may represent three or possibly four discrete glaciations, although evidence for a glacial origin of the Bayisi and Altungol diamictite is ambiguous. To constrain their age and duration, we dated three volcanic beds (V1,...

Earth's climate has changed, within life-sustaining bounds, from warm to cool intervals, on scales from thousands to hundreds of millions of years. In the Phanerozoic Eon there have been three intervals of glaciation (Ordovician, Carboniferous and Cenozoic) lasting tens of millions of years, with ice down to sea level at mid-latitudes (Frakes et al., 1992; Crowell, 1999). These cool " ice-house...

Neoproterozoic sedimentary successions worldwide display evidence for multiple low-latitude glacial events and continental rifting episodes related to the fragmentation of the supercontinent Rodinia. In Death Valley, eastern California, these events are represented by two intervals of glacial diamictite and two episodes of synsedimentary extensional faulting in the Kingston Peak Formation. Deep...

a brief account of the representative and workable industrial minerals namely magnesite, talc and barite in lesser himalaya, is presented here emphasizing their genesis. deposits of magnesite and talc are found associated with neoproterozoic, plateform type, shelf-slope limestone-dolomite host rocks from inner lesser himalayan sequences. field, textural, geochemical signatures and fluid inclusi...

We present a new and innovative way of determining the oxygen level of Earth’s past atmosphere by directly measuring inclusion gases trapped in halite. After intensive screening using multiple depositional, textural/fabric, and geochemical parameters, we determined that tectonically undisturbed cumulate, chevron, and cornet halite inclusions may retain atmospheric gas during crystallization fro...

The Neoproterozoic contains severe glacial intervals (750–580 Ma) including two extending to low palaeomagnetic latitudes. Paucity of radiometric dates indicates the need for chronostratigraphic tools. Whereas the marine Sr/Sr signatures show a steady rise, C fluctuates, the most reproducible variations being negative signatures in carbonate caps to glacial units, but more diagenetic work is ne...