ISBN10: 0813723779, ISBN13: 9780813723778, [publisher: Geological Society of Amer] Softcover Very Good
[liverpool, United Kingdom] [Publication Year: 2004]

ISBN10: 0813723779, ISBN13: 9780813723778, [publisher: Boulder, Colorado, USA : The Geological Society of America] Softcover The Tobacco Root Mountains occupy a unique niche in the Archean Wyoming province of North America. Located near the northwestern margin of the province, the Precambrian rocks of the Tobacco Root Mountains were subjected to an intense tectonothermal event (Big Sky Orogeny) during the collision of the Wyoming and Hearne provinces in the Early Proterozoic. This event overprinted earlier periods of deformation and metamorphism, but the unique lithologic packages present in the Tobacco Root Mountains aid in unraveling early from later events and in detailing many results stemming from this Early Proterozoic collision. Several papers in this volume review the geochemistry and petrology of the four major Precambrian rock sequences present in the Tobacco Root Mountains, focusing on what each rock suite represents in terms of original protolith and providing the foundation for understanding the extensive petrological and geochronological information that follows. Another paper considers the meta-ultramafic rocks that are dispersed throughout all Precambrian exposures in the Tobacco Root Mountains. Petrologic observations from all four rock suites are interpreted in terms of a metamorphic history and a pressure-temperature path for the Tobacco Root Mountains during the Proterozoic event. Numerous and extensive radiometric age determinations from all ...