Late Jurassic--Early Cretaceous cooling for Late Proterozoic through Early Devonian crystalline rocks from the Bronson Hill anticlinorium, MA--VT: Evidence from apatite fission track analysis

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

OSTI ID:5588025

Roden, M K ^[1]

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1. Rensselaer Polytechnic Inst., Troy, NY (United States). Dept. of Earth and Environmental Science

Ten samples of crystalline rocks from the Bronson Hill anticlinorium in north central Massachusetts--south central Vermont yield Mesozoic apatite fission track cooling ages ranging from 98 [+-] 8 to 158 [+-] 24 Ma. Compositionally, the samples include a quartz-phyric rhyolite from the Ammonoosuc Volcanics, a pegmatite from the Kempfield Anticline, a gabbro from the Prescott Intrusive Complex, the Dry Hill and Fourmile Gneisses from the Pelham Dome, Swanzey Gneiss from the Keene Dome, Pauchaug Gneiss from the Warwick Dome, and the Monson Gneiss. Published U-Pb zircon analyses for the same samples yield ages of 613 [+-] 3 Ma for the Dry Hill Gneiss; 454--442 [+-] 3 Ma for the Swanzey, Pauchaug, Monson and Fourmile Gneisses; 453 [+-] 2 Ma for the Ammonoosuc Volcanics; and 407 [+-] 3/[minus]2 Ma for the Prescott Intrusive Complex gabbro (Tucker and Robinson, 1990). Apatite fission track ages are all reset and increase in apparent age eastward from the edge of the Deerfield-Hartford Basin, consistent with published apatite fission track ages from Jurassic sedimentary units within the Deerfield and Northern Hartford Basins. Mean track lengths ranged from 13.4 to 14.4 [mu]m with moderately large standard deviations. These track length distributions suggest relatively slow cooling through the track annealing range of 70--90 C and are consistent with track length distributions for sedimentary samples within the Deerfield and Northern Hartford Basins. The trend of increasing apatite fission track apparent age eastward from the basin margin suggests several interpretations: (1) differential uplift; (2) deeper burial in the basin and adjacent areas; (3) higher heat flow along the basin margin. Zircon fission track analyses are in progress to constrain maximum burial depths and should help differentiate between these models.

• OSTI ID: 5588025
• Report Number(s): CONF-9303211-; CODEN: GAAPBC
• Journal Information: Geological Society of America, Abstracts with Programs; (United States), Vol. 25:2; Conference: 28. annual Geological Society of America (GSA) Northeastern Section meeting, Burlington, VT (United States), 22-24 Mar 1993; ISSN 0016-7592
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
GEOLOGIC DEPOSITS
AGE ESTIMATION
GEOTHERMOMETRY
MASSACHUSETTS
VERMONT
APATITES
CRETACEOUS PERIOD
FISSION TRACKS
GABBROS
GEOLOGIC HISTORY
GEOTHERMOMETERS
GNEISSES
JURASSIC PERIOD
PEGMATITES
RHYOLITES
ZIRCON
DEVELOPED COUNTRIES
GEOLOGIC AGES
IGNEOUS ROCKS
MEASURING INSTRUMENTS
MESOZOIC ERA
METAMORPHIC ROCKS
MINERALS
NORTH AMERICA
PARTICLE TRACKS
PHOSPHATE MINERALS
PLUTONIC ROCKS
ROCKS
SILICATE MINERALS
THERMOMETERS
USA
VOLCANIC ROCKS
580000* - Geosciences