Download or read book Structure of the Pre Beltian Metamorphic Rocks of the Northern Ruby Range Southwestern Montana written by Lawrence Paul Karasevich and published by . This book was released on 1980 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structural Analysis of the Pre Beltian Metamorphic Rocks of the Southern Highland Mountains Madison and Silver Bow Counties Montana written by Mack Stewart Duncan and published by . This book was released on 1976 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt: Approximately 240km2 of pre-Beltian metamorphic rocks are exposed in the southern portion of the Highland Mountains, Montana. At least six periods of deformation are indicated for these rocks, two of which are believed to have been accompanied by metamorphism. Three major lithologic units, quartzo-feldspathic gneiss, garnetiferous gneiss, and micaceous gneiss, serve as a crude stratigraphic sequence and help delineate two macroscopic structures, the Rochester antiform and the Gilfoy Hills synform. The axes of both of these folds trend NE-SW. The absence of a more detailed stratigraphy and the scarcity of exposures make structural analysis the most effective means of evaluating the deformational styles and orientations present in the map area. Lineation and foliation diagrams were prepared by computer using fabric element orientation data from over 1800 stations. Differences in structural style and orientation indicate that the two types of quartzo-feldspathic gneiss, leucocratic gneiss and gray gneiss, have undergone different deformational histories. The leucocratic gneiss, which is the lowermost unit exposed in the Rochester antiform, exhibits a similar style of folding, many reversals in dip direction, and a statistical axis of folding which plunges to the east-northeast. This geometry is attributed to a metamorphic/deformational event (M1/D1) which occurred prior to the accumulation of the gray, garnetiferous, and micaceous gneisses. These overlying units exhibit a concentric style of folding and a statistical axis of folding which plunges to the southwest. A subsequent metamorphic/deformational event (M2/D2) is believed to have produced this geometry. Mineral assemblages in the garnetiferous and micaceous gneisses indicate that temperatures between 650-700°C and pressures between 3/5kb were reached during M2/D2. Later deformational events, D3, D4, D5, and D6, all involved faulting of some type and are not believed to have been accompanied by metamorphism. A Laramide-age, metamorphic event, M3, is indicated by the occurrence of cordierite near contacts with the Laramide-age Hells Canyon pluton and Boulder batholith. A northeast-southwest trending fold system is present throughout most of the Precambrian metamorphic terrain in the Highland Mountains, the Tobacco Root Mountains, the Ruby Range, the Gravelly Range, and the Madison Range. The structural styles present within these areas indicates that the northeast-southwest trending fold system in southwestern Montana was produced by a primary stress coming from the southeast. Nappe-like overthrusting is suggested as a possible explaination for the anomalous structural sytle present in the northern Tobacco Root Mountains.
Download or read book U S Geological Survey Professional Paper written by and published by . This book was released on 1984 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Paleozoic and Mesozoic Stratigraphy of the Northern Part of the Ruby Range Southwestern Montana written by Russell G. Tysdal and published by . This book was released on 1976 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structure of the Southwestern Ruby Range Near Dillon Montana written by Angelo Frederick Okuma and published by . This book was released on 1971 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Basement Tectonics 8 written by Mervin J. Bartholomew and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 729 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 8th International Conference on Basement Tectonics was held in Butte, Montana, August 8-12,1988. Historically, basement tectonics conferences have focused on such topics as reactivation of faults, the influence of basement faults on metallogeny and hyrocarbon accumulation, and the use of geophysical and remote sensing techniques to interpret subsurface and surface geology. The 8th Conference diverged from past conferences in that a unifying theme was selected. Because ancient major terrane or cratonic boundaries are often postulated to be fault zones which are subsequently reactivated, the conference was organized to examine all aspects of ancient continental margins and terrane boundaries and to compare younger (Mesozoic) ones, about which more is known, with older (Paleozoic and Precambrian) ones. Moreover, because the 8th Conference was held in the northwestern United States, a greater emphasis was placed on the Mesozoic margin of western North America and the North American shield. The seven oral sessions and four poster sessions all dealt with aspects of the conference theme: characterization and comparison of ancient continental margins. The organizers extend their thanks to those individuals who graciously consented to serve as moderators for the oral sessions: John M. Bartley, Mark S. Gettings, M. Charles Gilbert, John M. Guilbert, Donald W. Hyndman, William P. Leeman, Robert Mason, and A. Krishna Sinha. The program with abstracts volume was prepared by S. E. Lewis and M. J. Bartholomew.
Download or read book Geological Survey Professional Paper written by and published by . This book was released on 1982 with total page 672 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Geology of the North End of the Ruby Range Southwestern Montana written by Russell G. Tysdal and published by . This book was released on 1970 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dillion Resource Area Wilderness Designation written by and published by . This book was released on 1987 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Montana Geological Society Field Conference Symposium Guidebook to Southwest Montana written by Montana Geological Society. Field Conference & Symposium and published by . This book was released on 1981 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Wilderness Planning Amendment environmental Impact Statement for the Dillon Resource Area Beaverhead and Madison Counties Montana written by and published by . This book was released on 1987 with total page 303 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Wilderness Planning Amendment environmental Impact Statement for the Dillon Resource Area written by and published by . This book was released on 1982 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mineral Resources of the Blacktail Mountains Wilderness Study Area Beaverhead County Montana written by Russell G. Tysdal and published by . This book was released on 1988 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book U S Geological Survey Bulletin written by and published by . This book was released on 1983 with total page 598 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bibliography and Index of Montana Geology written by and published by . This book was released on 1994 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Precambrian Geology and Bedded Iron Deposits of the Southwestern Ruby Range Montana written by Harold Lloyd James and published by . This book was released on 1990 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: A synthesis of present knowledge of the Precambrian geology and mineral deposits of the southwestern Ruby Range, Montana.
Download or read book Bibliography and Index of Montana Geology 1980 82 written by and published by . This book was released on 1994 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt:
