Late Pliocene Dawson Cut Forest Bed and new tephrochronological findings in the Gold Hill Loess, east-central Alaska
T.L. Pw et al., Department of Geology, Arizona State University, Tempe, Arizona 85287, USA. Pages 294-320.
Thick, wind-blown deposits (loess) in the Fairbanks region of interior Alaska are a rich source of information on past climates and environments during the last three million years. Pw et al. find that a buried forest bed in the lower part of this loess record contains fossil tree remains, pollen, tree-ring characteristics, and carbon isotopic signatures that are very similar to the modern boreal forest of central Alaska. Associated volcanic ash beds suggest that this buried forest bed is about two million years old, so that the northern boreal forest of northwestern North America, as we know it today, likely has a very long history.
U-Pb ages (3.8-2.7 Ga) and Nd isotope data from the newly identified Eoarchean Nuvvuagittuq supracrustal belt, Superior Craton, Canada
Jean David et al., GEOTOP-UQAM-McGill and Dept. des Sciences de la Terre et de l'Atmosphere, Universite du Quebec a Montreal, C.P. 8888, Succursale Centre-Ville, Montreal, Quebec H3C 3P8, Canada. Pages 150-163.
The geologic record of the early Earth is sparse due to the continual reworking of Earth's surface by geological processes. A few remnants of early crust (greater than 3.7 billion years ago) do remain, but are often highly deformed and the original rock features are often obliterated. David et al.'s study of the Nuvvuagittuq volcano-sedimentary sequence in the northeast Superior Province of northern Quebec, Canada, indicates an age of
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