Download or read book A Petrological and Geochemical Study of Mantle and Crustal Xenoliths from Lanzarote Canary Islands written by Caitlin Mary Traver and published by . This book was released on 2013 with total page 85 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study aims to evaluate the processes by which ocean island basalt-derived mantle xenoliths are depleted and, in some cases, subsequently re-fertilized using extremely depleted mantle xenoliths from Lanzarote, Canary Islands. New petrography, mineral-chemistry and whole-rock data are reported for>40 Lanzarote xenoliths, ranging from ultra-depleted harzburgites to re-fertilized lherzolites and gabbroic crustal samples. Previous studies of mantle xenoliths from Lanzarote report whole rock and mineral chemistries for only general categories of mantle peridotites, e.g. dunites, protogranular harzburgites and lherzolites, and melt-influenced textured xenoliths. In these studies, there are few detailed textural and chemical sample-specific connections reported. This study investigates and reports on chemistries and textures of individual samples, as they prove to be intrinsically related. These samples come from a total of six separate sampling sites on Lanzarote, representing one of the most comprehensive petrological studies yet performed on xenoliths from any oceanic island. This study focuses on identifying levels of melt depletion and later melt infiltration into mantle xenoliths and to provide a framework for understanding processes acting on the mantle beneath the Canary Islands.
Download or read book Petrology and Geochemistry of Upper Mantle and Lower Crustal Xenoliths from Thailand written by Prinya Promprated and published by . This book was released on 2001 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mantle Xenoliths written by Peter H. Nixon and published by John Wiley & Sons. This book was released on 1987 with total page 900 pages. Available in PDF, EPUB and Kindle. Book excerpt: The eruption of deep-seated xenoliths in basaltic, alnoitic, kimberlitic, etc volcanoes provides the geologist with an important direct means of examining the fragments of the earth's mantle and lower crust.
Download or read book Petrological Evolution of the European Lithospheric Mantle written by Massimo Coltorti and published by Geological Society of London. This book was released on 2010 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: Selected conference papers from the European Mantle Workshop, EMAW, held Ferrara, 2007.
Download or read book The Geochemistry and Petrography of Crustal Xenoliths from La Olivina Mexico written by James V. Robinson and published by . This book was released on 1988 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mantle Convection and Surface Expressions written by Hauke Marquardt and published by John Wiley & Sons. This book was released on 2021-07-07 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: A multidisciplinary perspective on the dynamic processes occurring in Earth's mantle The convective motion of material in Earth's mantle, powered by heat from the deep interior of our planet, drives plate tectonics at the surface, generating earthquakes and volcanic activity. It shapes our familiar surface landscapes, and also stabilizes the oceans and atmosphere on geologic timescales. Mantle Convection and Surface Expressions brings together perspectives from observational geophysics, numerical modelling, geochemistry, and mineral physics to build a holistic picture of the deep Earth. It explores the dynamic processes occurring in the mantle as well as the associated heat and material cycles. Volume highlights include: Perspectives from different scientific disciplines with an emphasis on exploring synergies Current state of the mantle, its physical properties, compositional structure, and dynamic evolution Transport of heat and material through the mantle as constrained by geophysical observations, geochemical data and geodynamic model predictions Surface expressions of mantle dynamics and its control on planetary evolution and habitability The American Geophysical Union promotes discovery in Earth and space science for the benefit of humanity. Its publications disseminate scientific knowledge and provide resources for researchers, students, and professionals.
Download or read book The Petrology and Geochemistry of Diverse Crustal Xenoliths Tatara San Pedro Volcanic Complex Chilean Andes written by Fidel Costa Rodriguez and published by . This book was released on 2000 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: Deux groupes de xénolites ont été échantillonnés dans une lave dacitique du Volcán Holocène San Pedro (Andes du Chili ; 36°S, 71°51'W). Le groupe I est constituté de mélanorites à olivine qui sont co-magmatiques au volcanisme Holocène. Le groupe II consiste en des leuconorites à clinopyroxène et hornblende qui représentent des fragments du soubassement pré-quarternaire du volcan. Malgré leur différence d'âge et d'origine, ces deux groupes de xénolites ont enregistré des processus de migration de liquides riches en Si02 et H2O ou de fluides aqueux qui ont réagit avec l'olivine, le spinelle, les pyroxènes ou le plagioclase pour former d'importantes quantités de horblende (50%) et phlogopite (12%), expliquant ainsi l'abondance de hornblende dans les plutons gabbroïques calco-alcalins, comparée aux laves basaltiques ou basaltiques andésitiques présentes dans les zones de subduction.
Download or read book Quantification of the Modification of Cratonic Lithospheric Mantle by Major Tectono magmatic Events written by and published by . This book was released on 2018 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sixth Hutton Symposium on the Origin of Granites and Related Rocks written by John D. Clemens and published by Geological Society of America. This book was released on 2010 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Petrology Geochemistry and Geochronology of Lower crustal Xenoliths Central Mexico written by Gregory Barrington Pool and published by . This book was released on 1990 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Geology of the Canary Islands written by Valentin R. Troll and published by Elsevier. This book was released on 2016-05-26 with total page 637 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Geology of the Canary Islands provides a concise overview of the geology and volcanology of the Canary Islands, along with 27 carefully planned day excursions comprising trips on all of the islands. Each stop includes a description on how to approach a site and where to park with GPS locations provided. The book covers all the spectacular features of the islands, including active ocean island volcanoes whose origins are linked to a hot spot or plume causing anomalously hot mantle material to intrude the African plate, submarine volcanic sequences uplifted inside the islands, sub- aerial shield volcanoes, and the remains of giant lateral collapses. Through its clearly written and richly color-illustrated introduction and field guide, this book is essential reading for geologists who visit the Canary Islands, one of the largest and most fascinating active volcanic systems in Europe. - Includes a forward by Prof. C. J. Stillman (Trinity College Dublin), a leading expert on the volcanology and geology of the Canary Islands - Features 500 full color images, coupled with in-depth introductory text and a chapter on each island, followed by 27 guided excursions that include all of the seven islands of the archipelago - Familiarizes the reader with the variety of volcanic landforms and eruptive products in the Canary Islands and provides practical support in recognition, recording, and interpretation - Develops understanding of growth, evolution, and destruction of ocean island volcanoes, promoting temporal and spatial thinking within a given geological framework
Download or read book Ascent Rates of Magmas and Genesis Transport and Reactions of Mantle and Crustal Xenoliths of the 1949 Eruption on La Palma Canary Islands written by Andreas Klügel and published by . This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 2005 Joint Assembly written by American Geophysical Union. Joint Assembly and published by . This book was released on 2005 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Xenoliths written by Adrienne Melissa Long and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The word xenolith is Latin for strange (xeno) rock (lith). Mantle xenoliths are egg-shaped rocks comprised of olivine (ol) and orthopyroxene (opx) ± clinopyroxene (cpx), spinel (sp) and garnet (gt), and other trace minerals. Xenoliths are most frequently exhumed by explosive volcanoes. Worldwide, xenoliths show variations in petrology (e.g. Mercier and Nicholas, 1974, Kopylova et al., 2004), trace elements (Shaw et al., 2004) and P-T conditions (e.g. Macgregor, 1974, Nickel and Green, 1985, Finnerty and Boyd, 1987, Brey and Kohler, 1990). Interpretation of the variations in xenoliths worldwide greatly enhances our understanding of mantle processes. Xenoliths from two different sites are considered in this thesis. The site considered in Chapter One, Jericho Pipe in Northern Canada, is the diatreme of a diamondiferous kimberlite pipe containing mantle xenoliths from depths between ~45-220 km (Kopylova et al., 2004). Chapter Two is a study of xenoliths from Meerfelder Maar in the West Eifel Volcanic Field, Germany. Meerfelder Maar is the remnant of a phreatic eruption triggered by the encounter of hot magma with the water table that exhumed mantle xenoliths from ~70-80 km depth (Schmincke, 1983, Witt-Eichsceh, 2007). Chapter One describes our Matlab model of the paleo-geotherm below the North American Craton. We analyzed P-T data obtained using three geothermometers (Macgregor, 1974, Wells, 1977, Brey and Kohler, 1990) and three geobarometers (Nickel and Green, 1985, Finnerty and Boyd, 1987, Brey and Kohler, 1990) on xenoliths from Jericho Pipe in the Slave Craton area of Canada to generate possible geotherms for the Jericho Pipe region. Our geophysical model compares published heat flux data and surface heat production values with geothermobarometry conducted on Jericho xenoliths. Geothermometers and geobarometers respectively are compared and analyzed for accuracy and precision relative to the petrology of the Jericho region. Each geotherm shows a scatter in the data and change of slope of the best-fit line to the data between depths ~160 km and ~220 km (see Figures 1.7, 1.8, 1.11, 1.12, 1.15, 1.16). We hypothesize that this change of slope is resultant of mantle plume impingement at the basal Canadian Shield prior to the eruption of Jericho Pipe and other regional kimberlites. We use a Matlab-generated 1D thermal model based on code developed by Depine et al., (2008) to explore this hypothesis. Implied in this hypothesis and seen in the model (see Figures 1.7, 1.8, 1.11, 1.12, 1.15, 1.16) is that continental cratons do not cause underlying mantle to appreciably warm on a ~200 Ma timescale by acting as effective insulators for mantle material. Furthermore, the basal heating event must be geologically short-lived, spanning ~50 Myr (see Figures 1.7, 1.8, 1.11, 1.12, 1.15, 1.16). Chapter Two is an empirical FTIR study of water content in Meerfelder Maar xenoliths. The amount of water present in the mantle affects melt geochemistry (e.g. Shaw et al., 2005, Bolfan-Casanova, 2007) and subsequently mantle viscosity (Grant et al., 2007). Chapter Two considers water partitioning in the mantle below the Eifel region of Germany by looking at maps of water concentration within minerals and along grain boundaries as well as single spectra graphs of H2 O and OH[-] at specific points within minerals. Meerfelder Maar xenoliths contain a high amount of molecular water in olivine and clinopyroxene and below average amount of molecular water in orthopyroxene (see Table 2.2) with respect to other xenoliths worldwide (Grant et al., 2007).
Download or read book Geochemistry and Petrology of Crustal Xenoliths from Xalapasco de la Joya State of San Luis Potosi Mexico written by Concepcion Gomez-Moran and published by . This book was released on 1986 with total page 618 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Geochemical and Isotopic Studies of Mantle derived Ultrabasic Xenoliths written by Simon Beswetherick and published by . This book was released on 1983 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Evolution of the Oceanic Lithospheric Mantle written by Archana Shejwalkar and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The oceanic lithosphere forms as a residue of partial melting of the mantle beneath the mid-ocean ridge axis. Subduction of this residual layer has a profound impact on the Earth's thermal and geochemical cycles as the recycling of this layer facilitates heat loss from the Earth's interior and induces geochemical heterogeneities in the mantle. The goal of this study is to understand the thermal and geochemical evolution of the oceanic lithospheric mantle from a petrological perspective. An empirical geobarometer is calibrated for ocean island xenoliths in order to understand the thermal structure of the oceanic lithospheric mantle. The results of 0.1 MPa experiments from this study and high-pressure experiments from previous studies are used in the calibration. The uncertainties on pressures derived using the above geobarometer are high and hence could not be tested against thermal models for the oceanic lithosphere. The geochemical evolution of the oceanic lithospheric mantle involves post-melting geochemical modifications such as metasomatism. The geochemical evolution of the uppermost oceanic lithospheric mantle is studied using harzburgites from Hess Deep ODP Site 895, which are depleted in moderately incompatible elements relative to the global suite of abyssal peridotites. A comparison between Yb-abundances in Hess Deep harzburgitesiiiivand those of a model depleted MORB mantle (DMM) residue reveals that the harzburgites have undergone up to 25% melting, assuming 0.5% melt porosity. Higher light and middle rare earth elements in the Hess Deep harzburgites than the model DMM melting residue are interpreted as the result of plagioclase crystallisation from melts being extracted by diffuse porous flow through the upper mantle. The effect of plagioclase crystallisation does not affect the chemistry of residual mineral phases as evidenced from the depleted light rare earth element abundances in clinopyroxene relative to the bulk rock. Ocean island xenoliths are studied to understand when and where metasomatism occurs in the deeper portion of the oceanic lithosphere. The median values of measured and reconstructed bulk concentration of Al2O3 in most ocean island xenoliths is lower than in abyssal peridotites, which generally would be interpreted as indicating a higher extent of melting in the former. However, a comparison between Yb- abundances in ocean island xenoliths and abyssal peridotites with a model DMM melting residue suggests that the extents of melting in the suites of rocks are broadly similar. Although fewer in number than ocean island xenoliths, abyssal peridotites from several locations have low concentrations of moderately incompatible elements. Metasomatism is observed in both, ocean island xenoliths and abyssal peridotites in the form of higher bulk rock Ce and Nd concentration than the model DMM melting residue but the extent of metasomatism is higher in ocean island xenoliths. There is no correlation between the concentrations of bulk rock Ce, Nd, Sm and Eu of ocean island xenoliths and age of the oceanic lithosphere from which the xenoliths originate. It is interpreted that metasomatism in the lower oceanic lithospheric mantle occurs near the ridge axis above the wings of the melting column.
