Download or read book Major and Trace element Analyses of Steens Basalt Southeastern Oregon written by and published by . This book was released on 1998 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Volcanoes to Vineyards written by Jim E. O'Connor and published by Geological Society of America. This book was released on 2009 with total page 886 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This volume contains guides for 34 geological field trips offered in conjunction with the October 2009 GSA Annual Meeting in Portland, Oregon. Showcasing the region's geological diversity, the peer-reviewed papers included here span topics ranging from accreted terrains and mantle plumes to volcanoes, floods, and vineyard terroir. Locations visited throughout Oregon, Washington, and Idaho encompass Astoria to Zillah. More than just a series of maps, the accompanying descriptions, observations, and conclusions offer new insights to the geologic processes and history of the Pacific Northwest - insights that will inspire readers to put their boots on the evidence as they develop their own understanding of this remarkable and dynamic corner of the world."--Publisher's description.
Download or read book The Columbia River Flood Basalt Province written by Stephen P. Reidel and published by Geological Society of America. This book was released on 2013-09-13 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Miocene Columbia River flood basalt province covers ~210,000 km2 of the Pacific Northwest of the United States, and forms part of a larger volcanic region that also includes contemporaneous silicic centers in northern Nevada, the basaltic and time-transgressive rhyolitic volcanic fields of the Snake River Plain and Yellowstone plateau, and the High Lava Plains of central Oregon. The Columbia River flood basalt province is accessible and well exposed, making it one of the best-studied flood basalt provinces worldwide, and it serves as a model for understanding the stratigraphic development and petrogenesis of large igneous provinces through time. This volume details our current knowledge of the stratigraphy and physical volcanology; extent, volume, and age of the lava flows; the tectonic setting and history of the province; the petrogenesis of the lavas; and hydrogeology of the basalt aquifers.
Download or read book New Publications of the Geological Survey written by Geological Survey (U.S.) and published by . This book was released on 1999 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Publications of the Geological Survey written by Geological Survey (U.S.) and published by . This book was released on 1986 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Geology and Petrologic Evolution of the Silicic to Intermediate Volcanic Rocks Underneath Steens Mountain Basalt SE Oregon written by Vera W. Langer and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Steens Mountain in SE Oregon is part of the northern Basin and Range Province, and represents a horst tilted about 100 to the west that is bounded to the east by a high angle, NNE trending normal fault. The minimum displacement is about 1200 m. Volcanic rocks, exposed along the eastern escarpment, range from basalt to high-silica rhyolite. By establishing a stratigraphy and determining chemical variations in the volcanic rock sequence underlying Steens Mountain Basalt, it was possible to evaluate the origin of this volcanism and the role of crustal contamination, explain its chemical variation with time, and relate the chemical evolution to extensional processes. The necessary chemical data were obtained by X-ray fluorescence, electron microprobe, and instrumental neutron activation analyses; field mapping provided information about stratigraphy and structure. The oldest units are lake sediments which are overlain by a volcanic rock sequence that proceeded from early rhyolitic tuffs to rhyolitic lava flows, dacites, andesites, and culminated with the eruption of Steens Mountain Basalt (S MB). All stratigraphic units are tilted to the NW or SW to various degrees. Early sediments and rhyolitic tuffs are tilted as much as 25°; whereas younger andesites (15° tilt), and SMB (5-10° tilt) overlie the older units unconformably. The stratigraphy and mapped unconformities indicate that active, volcanic episodes alternated with episodes of erosion and block tilting. Tilting events are thought to be connected to extensional tectonics, and the maximum extension for the Steens Mountain area is estimated to be 30%. Relationships between basalt, andesites, dacites, and rhyolites of the Steens Mountain volcanic suite are complex. Crystal fractionation alone cannot relate the different rocks to each other. Trace element chemistry of intermediate compositions requires fractional crystsllization plus large degrees of assimilation and magma mixing. Magma mixing is also suggested by different plagioclase populations and zoningpatterns in plagioclase and dinopyroxene phenocrysts from intermediate rock compositions. The role of assimilation is greater in the andesites and that of mixing in the dacites. The silicic mixing partner has to be extremely low in rare earth elements. Rhyolites are not directly related to the rest of the suite, but are related to each other by crystal fractionation. They most likely evolved from a partial melt of depleted crust (probably lower crust) by fractionation. Assimilation coupled with fractionation and simple magma mixing are typical magma processes for major metaluminous volcanic suites in the Basin and Range and elsewhere. These processes decrease the density of stagnated basaltic melts and subsequently increase their buoyancy. Extension triggers the ascent of mafic magma, but small amounts of extension alone do not increase the mean crustal density enough for basalts to rise to the surface. Increasing the crustal density by injection of mafic plutons and extension is able to produce a shift in volcanism from intermediate to more basaltic compositions as seen at Steens Mountain, where the influence of crustal material decreases upwards in the volcanic sequence.
Download or read book Plates Plumes and Planetary Processes written by Gillian R. Foulger and published by Geological Society of America. This book was released on 2007 with total page 1012 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents a collection of papers discussing various hypotheses and models of planetary plumes.
Download or read book New Publications of the U S Geological Survey written by and published by . This book was released on 1998 with total page 616 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Andean Magmatism written by Russell S. Harmon and published by . This book was released on 1984 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Major Oxide Trace Element and Glass Chemistry of Columbia River Basalt Samples Collected Between 1971 and 1977 written by Thomas Llewellyn Wright and published by . This book was released on 1979 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proterozoic Nuna to Pleistocene Megafloods written by Mark D. McFaddan and published by Geological Society of America. This book was released on 2024-05-23 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Volcanism and Tectonism in the Columbia River Flood basalt Province written by Stephen P. Reidel and published by Geological Society of America. This book was released on 1989 with total page 403 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bulletin State of Oregon Department of Geology and Mineral Industries written by Oregon. Department of Geology and Mineral Industries and published by . This book was released on 1937 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Trace Elements in High Cascade Volcanic Rocks written by Gary Jacob Anttonen and published by . This book was released on 1972 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Geological Society of America Bulletin written by Geological Society of America and published by . This book was released on 1976 with total page 976 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vols. 1-44 include Proceedings of the annual meeting, 1889-1933, later published separately.
Download or read book Continental Flood Basalts written by J. D. Macdougall and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Geology and Ore Deposits 2000 written by Geological Society of Nevada. Symposium and published by . This book was released on 2000 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt:
