Timing of middle Paleozoic (Acadian) metamorphism in the southern Appalachians: K-Ar studies in the Talladega belt, Alabama

Journal Article · Sun Jul 01 00:00:00 EDT 1990 · Geology; (USA)

DOI:https://doi.org/10.1130/0091-7613(1990)018<0650:TOMPAM>2.3.CO;2· OSTI ID:6357376

Kish, S A ^[1]

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1. Florida State Univ., Tallahassee (USA)

The Talladega belt of Alabama and Georgia is located at the southernmost exposed part of the southern Appalachian orogen and is one of the westernmost metamorphic terranes in this part of the orogen. The presence of the Lower Devonian Jemison Chert of the Talladega Group provides a maximum age for the timing of greenschist facies metamorphism and penetrative slaty cleavage formation in this terrane. Six slate collected form upper Precambrian( )-Lower Cambrian, and Silurian( )-Devonian rocks of the Talladega belt have an average K-Ar age of 399 {plus minus} 17 Ma. This age is interpreted to be the approximate time of regional greenschist facies metamorphism. The timing of metamorphism in the Talladega belt is similar to the age of the Acadian orogeny in the Maritime and northern Appalachians. Unlike the accreted nature of the Acadian terranes in the northern Appalachians, the Talladega belt appears to have been part of the early to middle Paleozoic cratonic margin of North America. The results of this study indicate that Acadian dynamothermal events extended into parts of the Laurentian margin in the southern Appalachians. Paleozoic igneous activity in the southern Appalachians was less extensive compared with the voluminous Acadian plutonism of the northern Appalachians; however, synkinematic to postkinematic Devonian plutons are present in the central and western parts of the orogen.

• OSTI ID: 6357376
• Journal Information: Geology; (USA), Vol. 18:7; ISSN 0091-7613
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
ALABAMA
APPALACHIAN BASIN
METAMORPHISM
AGE ESTIMATION
APPALACHIAN MOUNTAINS
ARGON ISOTOPES
CAMBRIAN PERIOD
CHERT
CONTINENTAL MARGIN
DEVONIAN PERIOD
GEOLOGIC DEPOSITS
GEOLOGIC HISTORY
ISOTOPE DATING
ISOTOPE RATIO
NORTH AMERICA
OROGENESIS
PALEOZOIC ERA
PLUTONIC ROCKS
POTASSIUM ISOTOPES
PRECAMBRIAN ERA
SILURIAN PERIOD
ALKALI METAL ISOTOPES
FEDERAL REGION IV
GEOLOGIC AGES
GEOLOGIC STRUCTURES
IGNEOUS ROCKS
ISOTOPES
MOUNTAINS
ROCKS
SEDIMENTARY BASINS
SEDIMENTARY ROCKS
USA
580000* - Geosciences