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GEOREF RECORD

Chronology of igneous rocks associated with the Penokean Orogeny in Wisconsin

W. R. Van Schmus
Chronology of igneous rocks associated with the Penokean Orogeny in Wisconsin (in Selected studies of Archean gneisses and lower Proterozoic rocks, southern Canadian Shield, G. B. Morey (editor) and Gilbert N. Hanson (editor))
Special Paper - Geological Society of America (1980) (182): 159-168

Abstract

U/Pb analyses have been carried out on 36 zircon fractions representing 23 lower Proterozoic plutonic and volcanic units from throughout Wisconsin. These data, combined with published results from NE Wisconsin, allow detailed definition of the chronology of igneous events in Wisconsin associated with the Penokean orogeny. Two distinct pulses can be recognized. The older began with mafic and felsic volcanism 1859 + or - 20 m.y. ago and was followed immediately by tonalitic and granitic plutonism 1840 + or - m.y. ago. Structural studies indicate that these rocks were emplaced during the main phase of the orogeny. The second pulse consisted predominantly of rhyolite and granophyric granite and occurred about 1760 + or - 10 m.y. ago.


ISSN: 0072-1077
EISSN: 2331-219X
Coden: GSAPAZ
Serial Title: Special Paper - Geological Society of America
Serial Issue: 182
Title: Chronology of igneous rocks associated with the Penokean Orogeny in Wisconsin
Title: Selected studies of Archean gneisses and lower Proterozoic rocks, southern Canadian Shield
Author(s): Van Schmus, W. R.
Author(s): Morey, G. B.editor
Author(s): Hanson, Gilbert N.editor
Affiliation: Univ. Kans., Dep. Geol., Lawrence, KS, United States
Affiliation: Minn. Geol. Surv., Saint Paul, MN, United States
Pages: 159-168
Published: 1980
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
ISBN: 0-8137-2182-2
References: 47
Accession Number: 1982-024809
Categories: Geochronology
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 1 anal., 1 table, geol. sketch map
N41°00'00" - N50°00'00", W93°00'00" - W75°00'00"
N44°00'00" - N49°15'00", W96°30'00" - W80°30'00"
N42°30'00" - N47°00'00", W92°49'60" - W86°45'00"
Secondary Affiliation: State Univ. N.Y., USA, United States
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United KingdomTwickenhamUKUnited Kingdom
Update Code: 1982
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