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New paleomagnetic data from carboniferous volcanics and red beds from central New Brunswick
Author(s) -
Seguin Maurice K.,
Singh A.,
Fyffe L.
Publication year - 1985
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/gl012i002p00081
Subject(s) - paleomagnetism , sinistral and dextral , geology , carboniferous , paleontology , red beds , devonian , apparent polar wander , paleozoic , volcanic rock , permian , late devonian extinction , fault (geology) , seismology , volcano , sedimentary rock , structural basin
It has long been argued, on the basis of paleomagnetic data derived from Devonian, Carboniferous and Permian lithological units from eastern North America that a sinistral megashear of Carboniferous age parallels and lies within the faults delimiting the Appalachian‐Caledonian chains. Recent paleomagnetic studies in the northern Appalachians have cast doubt on the models of a Carboniferous offset. The geologic evidence suggests that only a small amount of dextral (and not sinistral) strike slip has occurred on faults which are parallel with pre‐Acadian paleogeographic realms. The purpose of this paleomagnetic study is to test the validity of the proposed left‐lateral motion at one of the sites of its presumed passage in central New Brunswick. Six sites (80 oriented specimens) in Carboniferous red beds and volcanics were collected on both sides of the Fredericton Fault and other parallel faults. After AF and thermal cleaning, the mean direction of magnetization is 158° + 38°; the fold test is indecisive. The corresponding paleopole is 135°E, 21°N and the paleolatitude 20°S. The paleopole positions and paleolatitudes are not significantly different on either side of the Fredericton fault and no left‐lateral motion was detected by paleomagnetic means. As no such motion was detected in south‐central New Brunswick and Newfoundland, it is possible but unlikely that it took place in northern New Brunswick and in the western Gaspé Peninsula. This contribution is useful in discussing possible motions of Acadia.