Age and composition of Archean crystalline rocks from the southern Madison Range, Montana: Implications for crustal evolution in the Wyoming craton

Research Article| April 01, 1993 Age and composition of Archean crystalline rocks from the southern Madison Range, Montana: Implications for crustal evolution in the Wyoming craton PAUL A. MUELLER; PAUL A. MUELLER 1Department of Geology, University of Florida, Gainesville, Florida 32611 Search for other works by this author on: GSW Google Scholar ROBERT D. SHUSTER; ROBERT D. SHUSTER 1Department of Geology, University of Florida, Gainesville, Florida 32611 Search for other works by this author on: GSW Google Scholar JOSEPH L. WOODEN; JOSEPH L. WOODEN 2U. S. Geological Survey, 345 Middlefield Road, Menlo Park, California 94025 Search for other works by this author on: GSW Google Scholar ERIC A. ERSLEV; ERIC A. ERSLEV 3Department of Earth Resources, Colorado State University, Fort Collins, Colorado 80523 Search for other works by this author on: GSW Google Scholar DONALD R. BOWES DONALD R. BOWES 4Department of Geology and Applied Geology, Glasgow University, Glasgow G12 8QQ, Scotland Search for other works by this author on: GSW Google Scholar Author and Article Information PAUL A. MUELLER 1Department of Geology, University of Florida, Gainesville, Florida 32611 ROBERT D. SHUSTER 1Department of Geology, University of Florida, Gainesville, Florida 32611 JOSEPH L. WOODEN 2U. S. Geological Survey, 345 Middlefield Road, Menlo Park, California 94025 ERIC A. ERSLEV 3Department of Earth Resources, Colorado State University, Fort Collins, Colorado 80523 DONALD R. BOWES 4Department of Geology and Applied Geology, Glasgow University, Glasgow G12 8QQ, Scotland Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1993) 105 (4): 437–446. https://doi.org/10.1130/0016-7606(1993)105<0437:AACOAC>2.3.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Tools Icon Tools Get Permissions Search Site Citation PAUL A. MUELLER, ROBERT D. SHUSTER, JOSEPH L. WOODEN, ERIC A. ERSLEV, DONALD R. BOWES; Age and composition of Archean crystalline rocks from the southern Madison Range, Montana: Implications for crustal evolution in the Wyoming craton. GSA Bulletin 1993;; 105 (4): 437–446. doi: https://doi.org/10.1130/0016-7606(1993)105<0437:AACOAC>2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract The southern Madison Range of southwestern Montana contains two distinct Precambrian lithologic assemblages: (1) a complex of tonalitic to granitic gneisses that has been thrust over (2) a medium-grade metasupracrustal sequence dominated by pelitic schist. Crystallization ages for the protolith of a granodioritic gneiss that intruded the meta-supracrustal sequence (∼2.6 Ga) along with an intercalated meta-an-desite (∼2.7 Ga) confirm the sequence as Archean. Chemical (major and trace element), isotopic (Rb-Sr, Sm-Nd, Pb-Pb), and geochronologic (U-Pb zircon) data for selected components of the gneiss complex indicate two groups of gneisses: an older, tonalitic to trondhjemitic group (∼3.3 Ga) and a younger, mostly granitic group (∼2.7 Ga).Both groups of gneisses exhibit the radiogenic Pb and nonradiogenic Nd isotopic signature characteristic of Middle and Late Archean rocks from throughout the Wyoming province. The older gneisses, in particular, appear to be compositionally, isotopically, and chronologically comparable to other Middle Archean gneisses from the northern part of the province (for example, Beartooth Mountains). The Late Archean gneisses, however, exhibit some distinct differences relative to their temporal counterparts, including (1) trace-element patterns that are more suggestive of crustal melts than subduction activity and (2) higher initial Sr isotopic ratios that suggest more involvement of older crust in their petrogenesis. These comparisons suggest that the juxtaposition of Late Archean terranes in the northern Wyoming province was the result, at least in part, of intracratonic processes. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.