Paleomagnetic study of Mesozoic diabase in the Sassamansville syncline, PA: Implications for North American apparent polar wander

Conference · Mon Mar 01 04:00:00 EST 1993 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:5640015

Mowery, A ^[1]; Kodama, K P ^[2]

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1. Wellesley Coll., MA (United States). Geology Dept.
2. Lehigh Univ., Bethlehem, PA (United States). Earth and Environmental Sciences Dept.

A paleomagnetic study of the Mesozoic diabase intruding the Passaic formation in the Sassamansville syncline was conducted to determine the diabase's age of magnetization relative to the folding of the surrounding baked sediments. The timing of magnetization has important implications for the mid-Jurassic portion of North America's apparent polar wander (APW) path. If the Newark 2 (N2) magnetization previously reported by Smith and Noltimier (1979) for these rocks is corrected for local bedding tilt it supports the low latitude paleomagnetic Euler pole (PEP) APW path of Gordon, et al (1984). If the magnetization remains in geographic coordinates it supports high latitude mid-Jurassic poles calculated from secondary magnetizations recently isolated from Newark basin sediments and White Mountain instrusives. The confirmation of either path has consequences for both plate dynamics and the latitudinal displacement of southern Alaska tectonostratigraphic terranes. In the authors study they collected 8--10 individually oriented cores from 10 sites in the diabase. Modern stepwise alternating field and thermal demagnetization techniques were used to isolate the characteristic magnetization in each sample. Statistical tests show that the magnetization was acquired in either geographic or synfolding coordinates, but not prefolding coordinates. Although isothermal remanence acquisition and demagnetization experiments suggest that the magnetization is carried by magnetite which could be primary, the failure of a baked contact test strongly suggests the diabase has been remagnetized, probably during a hydrothermal event dated at approximately 180 my (Sutter, 1988). Therefore, the paleomagnetic pole calculated from the synfolding magnetization (74.1[degree]N, 48.8[degree]E) supports high latitude poles for the mid-Jurassic.

• OSTI ID: 5640015
• Report Number(s): CONF-9303211--
• Conference Information: Journal Name: Geological Society of America, Abstracts with Programs; (United States) Journal Volume: 25:2
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
BASALT
DEVELOPED COUNTRIES
DIABASES
GEOLOGIC AGES
GEOLOGIC FORMATIONS
GEOLOGIC HISTORY
GEOLOGIC MODELS
GEOLOGY
IGNEOUS ROCKS
JURASSIC PERIOD
MAGNETISM
MESOZOIC ERA
NORTH AMERICA
PALEOMAGNETISM
PENNSYLVANIA
PLATE TECTONICS
ROCKS
STRATIGRAPHY
TECTONICS
USA
VOLCANIC ROCKS