Download or read book Geochemical Mineralogical and Rock Magnetic Provenance Variation in Alaskan Abyssal Plain Sediments Gulf of Alaska written by Alexander David Ullrich and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Here, I address this hypothesis by developing preliminary source terrane signatures of fine-grained sediment and applying them to offshore sediments of the Surveyor Fan. This is done by employing multiple analytical tools shown to be effective in previous provenance studies, including trace and major elemental geochemistry, quantitative mineralogy, and environmental magnetic properties. Results of these analyses suggest that fine-grained sediments from the Orca and Valdez Groups of the Chugach-Prince William Terranes and the Kulthieth Formation of the Yakutat Terrane represent mafic and felsic compositional end members, respectively. Surveyor Fan samples are of an intermediate composition between these end members, with no apparent compositional distinction between upper and lower fan constituents. Variability in elemental composition, however, is significantly decreased in upper fan sediments supporting the hypothesis that transport pathways were isolated following the MPT at ca. 1 Ma.
Download or read book The Mineralogy of Suspended Sediment in Some Alaskan Glacial Streams and Lakes written by Allen R. Tice and published by . This book was released on 1972 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: Suspended sediments were collected from glacial streams and lakes close to the sources to determine if any physical or chemical weathering had occurred within them. The mineralogical composition and the major constituents were determined using X-ray diffraction. In almost all cases the composition of the samples paralleled that of the native parent materials, indicating that no chemical changes had occurred in the fine suspended material. (Author).
Download or read book A 37 000 year Record of Paleomagnetic and Environmental Magnetic Variability from Burial Lake Arctic Alaska written by Jason Michael Dorfman and published by . This book was released on 2013 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: Burial Lake sediments from the Noatak Basin in the northwest Brooks Range of Arctic Alaska (68.43°N, 159.17°W, 21.5 m water depth) provide the oldest continuous lacustrine record of paleo-environmental change and paleomagnetic secular variation (PSV) in eastern Beringia. A precise radiocarbon chronology, determined through accelerator mass spectrometry (AMS) allows us to independently constrain the region's climatic and geomagnetic evolution over the last ~37,000 years. Progressive alternating field (AF) demagnetization of u-channel samples and additionally acquired physical, geochemical, and rock-magnetic datasets, reveal three distinct lithologic subunits associated with the last glacial period (37.2 - 19.4 ka), the deglacial transition (19.4 - 9.8 ka), and the Holocene (9.8 ka - present). Rock magnetic variability suggests changes in sediment provenance associated with the transition from glacial to interglacial conditions. This is interpreted to result from a variable flux of aeolian derived sediment, and is supported by complimentary internal proxy data from Burial Lake. Other regional paleoclimate data, various glacial chronologies for the Brooks Range, and a relative sea level reconstruction facilitate a discussion of possible local, widespread, and far-field sources of dust, and the time-dependency of potential forcing mechanisms governing its production, availability, transport, and deposition. Results indicate an overall reduction in dust input from the glacial period to the Holocene that is largely attributed to increases in terrestrial and aquatic productivity, warming, and moisture availability, which limited widespread landscape deflation and production of dust. Subaerial continental shelves may have provided significant far-field sources of dust to interior Alaska during the glacial period, that were shut off by sea level inundation following the Last Glacial Maximum (LGM; 19 - 26.5 ka), further contributing to diminishing dust emissions. While glacial activity in the Brooks Range may provide local revenue of dust, activation of those deposits and timing of deposition in Burial Lake often appears to be more directly linked with general aridity, lack of vegetative cover, and increased windiness, rather than glacial advances or retreats. Despite this lithologic complexity, we isolate a stable, single-component characteristic remanent magnetization, carried predominately by low-coercivity (titano)magnetite in the pseudo single-domain (PSD) to multi-domain (MD) magnetic grain size range. We reconstruct directional paleomagnetic secular variation (PSV) over the full length of the record, and relative paleointensity (RPI) for the last ~14,700 years, which are consistent with available regional PSV records and continuous spherical harmonic model outputs. We observe only small deviations from geocentric axial dipole (GAD) predictions during the Holocene, while larger amplitude directional features are prevalent before 10 ka, and inclinations lay significantly shallower than GAD. While this may be related to lithology and the sediment magnetic acquisition process, regional records (including those derived from lava flows) indicate similar Holocene-Pleistocene discrepancies. Following on the "eccentric dipole" hypothesis, subdued secular variation and GAD-like behavior in the Pacific appears confined to the Holocene high-intensity state, showing greater variability as Pleistocene field strength diminishes, and/or the dipole axis is shifted away from the Pacific hemisphere. Long period trends in PSV from in the Alaskan Arctic are also similar in character to far-field sites (e.g., Hawaii and Siberia), suggesting large-scale coherent core-fluid flow regimes, expressed over surface geographical extents>5,000 km, and spanning Holocene-Pleistocene time intervals. The well-dated Burial Lake record fills a significant data gap in the growing Holocene paleomagnetic database, while allowing us to extend our understanding of PSV beyond the Holocene and into the Pleistocene, and continue the development of regional stratigraphic dating curves.
Download or read book Geochemical and rock magnetic records from sediments of the Cenozoic Pagodroma Group Prince Charles Mountains East Antarctica written by J. Bloemendal and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sedimentation and Heavy Mineral Distribution Northeastern Gulf of Alaska Continental Shelf written by Frederick Fenning Wright and published by . This book was released on 1969 with total page 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 1983 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sandstone Composition of the Valdez and Orca Groups Prince William Sound Alaska written by Julie A. Dumoulin and published by . This book was released on 1987 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Petroleum Abstracts written by and published by . This book was released on 1979 with total page 1268 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Petroleum Abstracts Literature and Patents written by and published by . This book was released on 1989 with total page 1528 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Marine Geochemistry written by Horst D. Schulz and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 463 pages. Available in PDF, EPUB and Kindle. Book excerpt: A summary of the latest research in this field. The topics comprise the sedimentological examination and physical properties of the sedimentary solid phase, pore water and pore water constituents, organic matter as the driving force of most microbiological processes, biotic and abiotic redox reactions, carbonates and stable isotopes as proxies for paleoclimate reconstruction, metal enrichments in ferromanganese nodules and crusts as well as in hot vents and cold seeps on the seafloor. The current model conceptions lead to the development of different types of computer models, allowing the global mass exchanges between oceans and sediments to be balanced.
Download or read book Marine Geology written by Jon Erickson and published by Infobase Publishing. This book was released on 2009 with total page 337 pages. Available in PDF, EPUB and Kindle. Book excerpt: This fully revised and expanded edition of "Marine Geology closely examines the interrelationship between water and its life forms and geologic structures. It looks at several ideas for the origins of the Earth
Download or read book Geologic Studies in Alaska by the U S Geological Survey During 1987 written by and published by . This book was released on 1988 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proxies in Late Cenozoic Paleoceanography written by C. Hillaire-Marcel and published by Elsevier. This book was released on 2007-05-25 with total page 863 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present volume is the first in a series of two books dedicated to the paleoceanography of the Late Cenozoic ocean. The need for an updated synthesis on paleoceanographic science is urgent, owing to the huge and very diversified progress made in this domain during the last decade. In addition, no comprehensive monography still exists in this domain. This is quite incomprehensible in view of the contribution of paleoceanographic research to our present understanding of the dynamics of the climate-ocean system. The focus on the Late Cenozoic ocean responds to two constraints. Firstly, most quantitative methods, notably those based on micropaleontological approaches, cannot be used back in time beyond a few million years at most. Secondly, the last few million years, with their strong climate oscillations, show specific high frequency changes of the ocean with a relatively reduced influcence of tectonics. The first volume addresses quantitative methodologies to reconstruct the dynamics of the ocean andthe second, major aspects of the ocean system (thermohaline circulation, carbon cycle, productivity, sea level etc.) and will also present regional synthesis about the paleoceanography of major the oceanic basins. In both cases, the focus is the “open ocean leaving aside nearshore processes that depend too much onlocal conditions. In this first volume, we have gathered up-to-date methodologies for the measurement and quantitative interpretation of tracers and proxies in deep sea sediments that allow reconstruction of a few key past-properties of the ocean( temperature, salinity, sea-ice cover, seasonal gradients, pH, ventilation, oceanic currents, thermohaline circulation, and paleoproductivity). Chapters encompass physical methods (conventional grain-size studies, tomodensitometry, magnetic and mineralogical properties), most current biological proxies (planktic and benthic foraminifers, deep sea corals, diatoms, coccoliths, dinocysts and biomarkers) and key geochemical tracers (trace elements, stable isotopes, radiogenic isotopes, and U-series). Contributors to the book and members of the review panel are among the best scientists in their specialty. They represent major European and North American laboratories and thus provide a priori guarantees to the quality and updat of the entire book. Scientists and graduate students in paleoclimatology, paleoceanography, climate modeling, and undergraduate and graduate students in marine geology represent the target audience. This volume should be of interest for scientists involved in several international programs, such as those linked to the IPCC (IODP – Integrated Ocean Drilling Program; PAGES – Past Global Changes; IMAGES – Marine Global Changes; PMIP: Paleoclimate Intercomparison Project; several IGCP projects etc.), That is, all programs that require access to time series illustrating changes in the climate-ocean system. Presents updated techniques and methods in paleoceanography Reviews the state-of-the-art interpretation of proxies used for quantitative reconstruction of the climate-ocean system Acts as a supplement for undergraduate and graduate courses in paleoceanography and marine geology
Download or read book Rock Magnetism written by David J. Dunlop and published by Cambridge University Press. This book was released on 1997 with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a comprehensive treatment of fine particle magnetism and the magnetic properties of rocks. Starting from atomic magnetism and magneotistic principles, the authors explain why domains and micromagnetic structures form in ferrmagnetic crystals and how these lead to magnetic memory in the form of thermal, chemical and other remanent magnetizations. This book will be of value to graduate students and researchers in geophysics and geology, particularly in palemagnetism and rock magnetism, as well as physicists and electrical engineers interested in fine-particle magnetism and magnetic recording.
Download or read book Quaternary Climates Environments and Magnetism written by Barbara A. Maher and published by Cambridge University Press. This book was released on 2010-11-25 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Quaternary has been a period of major climatic and environmental oscillations, and our knowledge of these past variations is important for our understanding of the possible impact of human activity on the present-day environment. Quaternary Climates, Environments and Magnetism presents an up-to-date account of the rich variety of uses of magnetic measurements in the environmental geosciences. Ten chapters by leading world authorities describe the highlights of environmental magnetic work during the past decade and identify directions for future research. This comprehensive and multidisciplinary coverage leads to a more thorough understanding of the environmental processes involved. This volume will be of interest to research scientists from a wide range of disciplines working on Quaternary environments, including earth and environmental sciences, physical geology, geography, and palaeoclimatology. It will also be valuable as a supplementary text for graduates and advanced undergraduates.
Download or read book Comprehensive Index of the Publications of the Association written by American Association of Petroleum Geologists and published by . This book was released on 1966 with total page 624 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Statistical Data Analysis Explained written by Clemens Reimann and published by John Wiley & Sons. This book was released on 2011-08-31 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt: Few books on statistical data analysis in the natural sciences are written at a level that a non-statistician will easily understand. This is a book written in colloquial language, avoiding mathematical formulae as much as possible, trying to explain statistical methods using examples and graphics instead. To use the book efficiently, readers should have some computer experience. The book starts with the simplest of statistical concepts and carries readers forward to a deeper and more extensive understanding of the use of statistics in environmental sciences. The book concerns the application of statistical and other computer methods to the management, analysis and display of spatial data. These data are characterised by including locations (geographic coordinates), which leads to the necessity of using maps to display the data and the results of the statistical methods. Although the book uses examples from applied geochemistry, and a large geochemical survey in particular, the principles and ideas equally well apply to other natural sciences, e.g., environmental sciences, pedology, hydrology, geography, forestry, ecology, and health sciences/epidemiology. The book is unique because it supplies direct access to software solutions (based on R, the Open Source version of the S-language for statistics) for applied environmental statistics. For all graphics and tables presented in the book, the R-scripts are provided in the form of executable R-scripts. In addition, a graphical user interface for R, called DAS+R, was developed for convenient, fast and interactive data analysis. Statistical Data Analysis Explained: Applied Environmental Statistics with R provides, on an accompanying website, the software to undertake all the procedures discussed, and the data employed for their description in the book.
