Low-latitude glaciation in the Palaeoproterozoic era
Article Abstract:
A paleomagnetic estimate of a depositional latitude for the lavas, as well as for the underlying contemporaneous glacial rocks, is reported. The paleolatitudinal estimate was derived from observations made of the Archaean-Paleoproterozoic 'Transvaal Supergroup' on the Kapvaal craton in South Africa. Within this supergroup are the Ongeluk lavas which conformably overlies glaciogenic deposits. The Ongeluk lavas are about 2.2 billion years old. It is hoped that such a study of the Earth's paleoclimate would provide a clue to the temporal and spatial distributions of Precambrian glaciations.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1997
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Glaciation and denudation rates
Article Abstract:
M.A. Summerfield and M.P. Kirkbride's citation of the research of D.M. Hicks and colleagues to support the hypothesis that glaciation does not increase denudation rates was incorrect. Summerfield and Kirkbride sought to cast doubt on the belief that rates of erosion are greater for glacial than for nonglacial processes. However, the use of the present-day spatial variations as surrogates for changes over time on which Hicks and colleagues relied has a limited applicability. Moreover, estimations of denudation rates are hampered by mistakes in measurement.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1992
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A driver of glaciation cycles?
Article Abstract:
Astronomers suggest that extraterrestrial material such as interplanetary dust particles (IDP) influence the Earth's climate, particularly terrestrial glaciation cycles. According to studies, there is a correlation between variations in the deep-sea sediment core and the succession of ice ages on Earth, suggesting that the climate cycle may be affected by the accretion rate of IDP in the atmosphere. It is also suggested that the inclination of the Earth's orbital plane affects accretion rate of IDP.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1995
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