Limestones of western Newfoundland that magnetized before Devonian folding but after Middle Ordovician lithification

Journal Article · Sat Dec 31 23:00:00 EST 1988 · Geophysical Research Letters (American Geophysical Union); (USA)

DOI:https://doi.org/10.1029/GL016i001p00093· OSTI ID:5542330

Hodych, J P ^[1]

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1. Memorial Univ. of Newfoundland, St. John's (Canada)

A positive fold test and a negative conglomerate test help determine when and how stable remanence was acquired in the Middle Ordovician Table Head Group limestones of the Port au Port Peninsula of Newfoundland. The limestones magnetized after lithification and incorporation as clasts into a Middle Ordovician breccia. Hence, the limestones do not carry a detrital or other primary remanence despite their very low conodont color alteration index. The remanence may be thermoviscous or diagenetic and was acquired before Devonian folding. This suggests the need for caution in interpreting paleomagnetic results from other early Paleozoic limestones whose remanence resides in magnetite of blocking temperature lower than 400C.

• OSTI ID: 5542330
• Journal Information: Geophysical Research Letters (American Geophysical Union); (USA), Journal Name: Geophysical Research Letters (American Geophysical Union); (USA) Vol. 16:1; ISSN 0094-8276; ISSN GPRLA
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
CANADA
CARBONATE ROCKS
CONGLOMERATES
DEVELOPED COUNTRIES
DEVONIAN PERIOD
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC HISTORY
ISLANDS
LIMESTONE
LITHOLOGY
MAGNETISM
MAGNETIZATION
NEWFOUNDLAND
NORTH AMERICA
ORDOVICIAN PERIOD
PALEOMAGNETISM
PALEOZOIC ERA
ROCKS
SEDIMENTARY ROCKS
TECTONICS