Download or read book The Nature and Origin of the Intermediate and Silicic Rocks and Their Mafic Inclusions at South Sister Volcano Central High Cascades written by Jonathan D. Price and published by . This book was released on 1993 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Baylor Geological Studies written by and published by . This book was released on 1994 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Petrogenesis of Compositionally Distinct Silicic Volcanoes in the Three Sisters Region of the Oregon Cascade Range written by Brittain E. Hill and published by . This book was released on 1991 with total page 470 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Three Sisters region of the Oregon High Cascades has developed three compositionally and petrogenetically distinct silicic (i.e., SiO2 [greater than or equal to] 58%) magma systems within the last 600 k.y. These silicic systems evolved from the same High Cascade mafic magma system and developed in the same 20x30 km area of the arc, but did not interact. The Broken Top system (BT) evolved to 71% SiO2 through a combination of plag + px + Fe-Ti oxides ± ap (PPFA) fractionation and 20%-35% mixing of rhyolitic (74% SiO2) crustal melts. In contrast, part of the Three Sisters system (3S) evolved to 66% SiO2 through PPFA fractionation alone, while other parts evolved to 66% SiO2 through PPFA fractionation coupled with [greater than or equal to} 40% mixing of rhyolitic ([greater than or equal to]72% SiO2) crustal melts. The 3S system was intermittently active from [less than or equal to] 340 ka to 2 ka. The petrogenesis of intermediate composition rocks at Middle Sister (340 ka, 100 ka) was controlled by PPFA fractionation to [less than or equal to] 66% SiO2. Rhyolite (72%-76% SiO2) was first erupted in the 3S system at [approximately] 100 ka, at the start of South Sister (SS) volcanism. Major and trace element abundances preclude derivation of 3S rhyolite through crystal fractionation, but are consistent with 20-30% dehydration melting of mafic amphibolite. The petrogenesis of intermediate composition rocks at SS was controlled by PPFA fractionation coupled with 30-40% rhyolitic magma mixing. However, the rhyolitic magma mixed into an essentially mafic system, which limited intermediate differentiation at SS to [less than or equal to] 66% SiO2. The BT system was active from [approximately] 600 ka to at least 200 ka. Major and trace element abundances preclude derivation of BT rhyolite (74% SiO2) through crystal fractionation, but are consistent with [approximately] 30% dehydration melting of older tonalitic intrusions. BT petrogenesis was controlled by PPFA fractionation accompanied by 10-20% mixing of rhyolitic magmas to [approximately] 63% SiO2, with [approximately] 30% rhyolite mixing from 63% to 71% SiO2. In contrast to the 3S system, differentiation proceeded beyond 66% SiO2 because rhyolitic magma was mixed into a more evolved ([approximately] 60%-65% SiO2) system. The observed temporal and spatial variations in petrogenesis were not controlled by regional changes in tectonic setting, crustal thickness or crustal composition. However, small-scale changes in the magnitude of crustal extension occurred in this area, and are thought to have controlled petrogenesis by localizing mid-crustal mafic magmatism and thus crustal heat flow.
Download or read book The Origin of Composition Gaps at South Sister Volcano High Cascades Central Oregon written by Scott Travis Dreher and published by . This book was released on 1996 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quaternary Magmatism in the Cascades written by Wes Hildreth and published by . This book was released on 2007 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Natural System of Volcanic Rocks written by Ferdinand Freiherr von Richthofen and published by . This book was released on 1868 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Volcanoes written by John P. Lockwood and published by John Wiley & Sons. This book was released on 2013-04-26 with total page 677 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volcanoes are essential elements in the delicate global balance of elemental forces that govern both the dynamic evolution of the Earth and the nature of Life itself. Without volcanic activity, life as we know it would not exist on our planet. Although beautiful to behold, volcanoes are also potentially destructive, and understanding their nature is critical to prevent major loss of life in the future. Richly illustrated with over 300 original color photographs and diagrams the book is written in an informal manner, with minimum use of jargon, and relies heavily on first-person, eye-witness accounts of eruptive activity at both "red" (effusive) and "grey" (explosive) volcanoes to illustrate the full spectrum of volcanic processes and their products. Decades of teaching in university classrooms and fieldwork on active volcanoes throughout the world have provided the authors with unique experiences that they have distilled into a highly readable textbook of lasting value. Questions for Thought, Study, and Discussion, Suggestions for Further Reading, and a comprehensive list of source references make this work a major resource for further study of volcanology. Volcanoes maintains three core foci: Global perspectives explain volcanoes in terms of their tectonic positions on Earth and their roles in earth history Environmental perspectives describe the essential role of volcanism in the moderation of terrestrial climate and atmosphere Humanitarian perspectives discuss the major influences of volcanoes on human societies. This latter is especially important as resource scarcities and environmental issues loom over our world, and as increasing numbers of people are threatened by volcanic hazards Readership Volcanologists, advanced undergraduate, and graduate students in earth science and related degree courses, and volcano enthusiasts worldwide. A companion website is also available for this title at www.wiley.com/go/lockwood/volcanoes
Download or read book The Origin of Secondary Silica in Volcanic Rocks Superstition Mountains Arizona written by Gerald D. Pollack and published by . This book was released on 2001 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Geologic Field trip Guide to the Volcanic and Hydrothermal Landscape of the Yellowstone Plateau written by Lisa A. Morgan and published by Government Printing Office. This book was released on 2017 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Petrology of Par cutin Volcano Mexico written by Ray Everett Wilcox and published by . This book was released on 1954 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Magmatic Systems written by Michael P. Ryan and published by Academic Press. This book was released on 1994-08-26 with total page 427 pages. Available in PDF, EPUB and Kindle. Book excerpt: With its integrated and cohesive coverage of the current research, Magmatic Systems skillfully explores the physical processes, mechanics, and dynamics of volcanism. The text utilizes a synthesized perspective--theoretical, experimental, and observational--to address the powerful regulatory mechanisms controlling the movement of melts and cooling, with emphasis on mantle plumes, mid-ocean ridges, and intraplate magmatism. Further coverage of subduction zone magmatism includes:Fluid mechanics of mixed magma migrationInternal structure of active systemsGrain-scale melt flowRheology of partial meltsNumerical simulation of porous media melt migrationNonlinear (chaotic and fractal) processes in magma transportIn all, Magmatic Systems will prove invaluable reading to those in search of an interdisciplinary perspective on this active topic. Key Features* Fluid mechanics of magma migration from surface region to eruption site* Internal structure of active magmatic systems* Grain-scale melt flow in mantle plumes and beneath mid-ocean ridges* Physics of magmatic systems and magma dynamics
Download or read book Origin and Mixing of Silicic and Mafic Magmas on Nisyros Volcano Greece written by Austin Reed and published by . This book was released on 2012 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Tertiary Volcanic Rocks of the Mt Daniel Area Central Washington Cascades written by Eric Robb Simonson and published by . This book was released on 1981 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Structures Origin and Nomenclature of the Acid Volcanic Rocks of South Mountain written by Florence Bascom (géologue).) and published by . This book was released on 1893 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Origin and Geochemical Evolution of Mafic Magmas from Mount Baker in the Northern Cascade Arc Washington written by Nicole E. Moore and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Five mafic lava flows located on the southern flank of Mount Baker are among the most primitive in the volcanic field. A comprehensive whole rock and mineral chemistry dataset (including major, trace, REE and isotopic abundances as well as petrography and mineral chemistry) reveals the diversity between these mafic lavas, which come from distinct sources and have been variably affected by ascent through the crust. Disequilibrium textures present in all of the lavas indicate that crustal processes have affected the magmas. Despite this evidence, mantle source characteristics have been retained, demonstrated by a lack of variation in the most highly incompatible elements, insignificant addition of crustal material, lack of an obvious crustal radiogenic source, and minimal chemical differences between lavas that are the result of mixing and their mafic endmembers. In evaluating mantle sources, four endmember lava types are represented. These include modified low-K tholeiitic basalt (LKOT-like), typical calc-alkaline (CA) lavas, high- Mg basaltic andesite (HMBA), and a second but distinct basaltic andesite. The first type, the basalt of Park Butte (49.3-50.3 wt.% SiO2, Mg# 64-65), is classified as low-K, and has major element chemistry similar to LKOT found elsewhere in the Cascades. Park Butte also has the lowest overall abundances of trace elements (with the exception of the HREE), indicating it is either derived from the most depleted mantle source or has undergone the largest degree of partial melting. A second lava type is represented by the basalts of Lake Shannon (50.7- 52.6 wt.% SiO2, Mg# 58-62) and Sulphur Creek (51.2-54.6 wt.% SiO2, Mg# 56-57). These two lavas are comparable to calc-alkaline rocks found in arcs worldwide, and have similar trace element patterns; however, they differ in abundances of REE, indicating variation in degree of partial melting or fractionation. The third lava type is represented by the basaltic andesite of Tarn Plateau (51.8-54.0 wt.% SiO2, Mg# 68-70), which has characteristics similar to high-Mg andesite worldwide. The second basaltic andesite unit, Cathedral Crag (52.2- 52.6 wt.% SiO2, Mg# 55-58), can be distinguished from the HMBA endmember because it has much lower MgO, Mg#, Ni and Cr, and is the least primitive of all the lavas in this study. The strongly depleted HREE nature of both basaltic andesite units suggests fractionation from a high-Mg basaltic parent (to a greater extent in the less primitive Cathedral Crag lavas) derived from a source with residual garnet is responsible for their generation. Assessment of the relative enrichment of a slab component in the lavas reveals that the calc-alkaline units are least enriched, the HMBA and basaltic andesite are intermediate, and the LKOT-like unit is most enriched in slab fluids. Petrogenetic indicators point to sediment as the primary slab fluid contributor, with a small role for altered oceanic crust fluids in the LKOT-like unit. Modeled fluid compositions support this assertion. Melt modeling indicates the LKOT-like and calc-alkaline lavas were generated by partial melting of a depleted spinel harzburgite, while the results for modeling HMBA and basaltic andesite units suggest a depleted garnet harzburgite source. Differences in primitiveness (i.e. MgO, Ni and Cr content) among the units are the result of differences in depth and degree of fractionation in the crust. A summary model is presented where 1) varying degrees of a primarily sediment-derived slab component infiltrate the mantle wedge; 2) slab flux assists in melting two distinct mantle sources; 3) melting occurs at various fractions, and the resulting melts stall at different levels in the crust; and 4) differentiation at a range of pressures to different degrees produces mafic magmas with diverse chemistry.
Download or read book Mafic Inclusions in Silicic Rocks in Santorini Greece written by Seyed-Mohsen Mortazavi-Ravari and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Essentials of Paleomagnetism written by Lisa Tauxe and published by Univ of California Press. This book was released on 2010-03-19 with total page 505 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This book by Lisa Tauxe and others is a marvelous tool for education and research in Paleomagnetism. Many students in the U.S. and around the world will welcome this publication, which was previously only available via the Internet. Professor Tauxe has performed a service for teaching and research that is utterly unique."—Neil D. Opdyke, University of Florida
