Preliminary paleomagnetic results from the Triassic Prida Formation (Lower Star Peak Group), west-central Nevada, and implications for latitudinal displacement

Journal Article · Tue May 01 00:00:00 EDT 1990 · Geophysical Research Letters (American Geophysical Union); (USA)

DOI:https://doi.org/10.1029/GL017i006p00697· OSTI ID:6206221

Geissman, J Wm ^[1]; Gillett, S L ^[2]; Oldow, J S ^[3]

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1. Univ. of New Mexico, Albuquerque (USA)
2. Univ. of Nevada, Reno (USA)
3. Rice Univ., Houston, TX (USA)

Paleomagnetic data were obtained from two oppositely dipping carbonate sections of the Triassic Prida Formation, lower Star Peak Group, in the Humboldt Range of west-central Nevada. Progressive demagnetization of the rocks indicated that the remanent magnetization consists of three or fewer vector components. A characteristic component, with the highest unblocking temperatures, was most effectively isolated by low temperature (200-300C) thermal followed by progressive alternating field demagnetization. The sections yield in situ mean directions that differ significantly, but that have similar inclinations (Star Canyon: D=311, I=+34, {alpha}95=5, k=22, N=38 samples; Fossil Hill: D=281, I=+33, {alpha}95=2{degree}, k=2814, N=3 section means, 154 samples). The directions diverge upon simple structural correction, from which the authors infer that at least one and probably both of the sections were remagnetized, probably in latest Middle to Late Jurassic time. These data cannot be used to indicate significant southward translation of Golconda allochthon rocks, as inferred from magnetizations in underlying volcanic rocks. The translation interpretation may require revision if magnetizations in the volcanic rocks are also secondary.

• OSTI ID: 6206221
• Journal Information: Geophysical Research Letters (American Geophysical Union); (USA), Vol. 17:6; ISSN 0094-8276
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
GEOLOGIC FORMATIONS
PALEOMAGNETISM
NEVADA
JURASSIC PERIOD
LATITUDE EFFECT
MAGNETIC FIELDS
ORIENTATION
STRATIGRAPHY
TRIASSIC PERIOD
VOLCANIC ROCKS
FEDERAL REGION IX
GEOGRAPHICAL VARIATIONS
GEOLOGIC AGES
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IGNEOUS ROCKS
MAGNETISM
MESOZOIC ERA
NORTH AMERICA
ROCKS
USA
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580000* - Geosciences