Paleomagnetic polarity reversals in Marinoan (ca. 600 Ma) glacial depositsof Australia: Implications for the duration of low-latitude glaciation in neoproterozoic time

Citation
Le. Sohl et al., Paleomagnetic polarity reversals in Marinoan (ca. 600 Ma) glacial depositsof Australia: Implications for the duration of low-latitude glaciation in neoproterozoic time, GEOL S AM B, 111(8), 1999, pp. 1120-1139
Citations number
143
Categorie Soggetti
Earth Sciences
Journal title
GEOLOGICAL SOCIETY OF AMERICA BULLETIN
ISSN journal
00167606 → ACNP
Volume
111
Issue
8
Year of publication
1999
Pages
1120 - 1139
Database
ISI
SICI code
0016-7606(199908)111:8<1120:PPRIM(>2.0.ZU;2-D
Abstract
A paleomagnetic investigation of Marinoan glacial and preglacial deposits i n Australia Was conducted to reevaluate Australia's paleogeographic positio n at the time of glaciation (ca. 610-575 Ma). The paleomagnetic results fro m the Elatina Formation of the central Flinders Ranges yield the first posi tive regional-scale fold test (significant at the 99% level), as well as at least three magnetic polarity intervals. Stratigraphic discontinuities typ ical of glacial successions prevent the application of a magnetic polarity stratigraphy to regional correlation, but the positive fold test and multip le reversals confirm the previous low paleolatitude interpretation of these rocks (mean D = 214.9 degrees, I = -14.7 degrees, alpha(95), = 12.7 degree s, paleolatitude = 7.5 degrees). The underlying preglacial Yaltipena Format ion also carries low magnetic inclinations (mean D = 204.0 degrees, I = -16 .4 degrees, alpha(95), = 11.0 degrees, paleolatitude = 8.4 degrees), sugges ting that Australia was located at low paleolatitude at the onset of glacia tion, The number of magnetic polarity intervals present within the Elatina Formation and the Elatina's lithostratigraphic relationship to other Marino an glacial deposits suggest that glaciation persisted at low latitudes in A ustralia for a minimum of several hundreds of thousands to millions of year s.