Zircon and apatite fission-track evidence for an Early Permian thermal peak and relatively rapid Late Permian cooling in the Appalachian Basin

Conference · Wed Jan 01 04:00:00 EST 1992 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:5808288

Roden, M K ^[1]; Wintsch, R P ^[2]

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1. Rensselaer Polytechnic Inst., Troy, NY (United States). Dept. of Earth and Environmental Science
2. Indiana Univ., Bloomington, IN (United States). Dept. of Geological Sciences

New zircon fission-track ages compliment published apatite fission-track ages in the Appalachian Basin to narrowly constrain its thermal history. Geologic evidence can only constrain timing of the thermal peak to be younger than late Pennsylvanian sediments ([approximately] 300 Ma) and older than Mesozoic sediments in the Newark and Gettysburg Basins ([approximately] 210 Ma). Apatite fission-track ages as old as 246 Ma require the Alleghanian thermal peak to have been pre-Triassic. Preliminary data on reset zircon fission-track ages from middle Paleozoic sediments range from 255 to 290 Ma. Zircon fission-track apparent ages from samples younger and structurally higher than these are not reset. Thus, the oldest reset zircon fission-track age constraints the time of the Alleghanian thermal peak to be earliest Permian. Rates of post-Alleghanian cooling have not been well-constrained by geologic data and could be very slow. The difference between apatite and zircon fission-track ages for most of the samples range from 100--120 m.y. reflecting Permo-Triassic cooling of only 1 C/m.y. However, one sample with one of the oldest apatite ages, 245 Ma, yields one of the younger zircon ages of 255 Ma. This requires cooling rates of 10 C/m.y. and uplift rates of [approximately] 0.5 mm/yr. Collectively, these data support an early Permian thermal peak and a two-stage cooling history, consisting of > 100 C cooling (> 8 km denundation) in the Permian followed by relatively slow cooling and exhumation throughout the Mesozoic.

• OSTI ID: 5808288
• Report Number(s): CONF-921058--
• Conference Information: Journal Name: Geological Society of America, Abstracts with Programs; (United States) Journal Volume: 24:7
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
AGE ESTIMATION
APATITES
APPALACHIAN BASIN
COOLING
FISSION TRACKS
GEOLOGIC AGES
GEOLOGIC HISTORY
GEOLOGIC STRUCTURES
GEOTHERMOMETRY
GROUND UPLIFT
MINERALS
PALEOZOIC ERA
PARTICLE TRACKS
PERMIAN PERIOD
PHOSPHATE MINERALS
RESERVOIR TEMPERATURE
SEDIMENTARY BASINS
SILICATE MINERALS
ZIRCON