Download or read book An Examination of Trace Element Concentrations Across Calcite aragonite Transitions in a Madagascan Stalagmite written by Kaylee Brent and published by . This book was released on 2017 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: Calcite and aragonite speleothems have been used for the past few decades to provide paleoclimate information, but in speleothems of mixed mineralogy the signal of mineral changes can complicate understanding of climate signals also present. This mineral signal must therefore be examined and controlled for. In this work, ICP-MS (inductively-coupled plasma mass spectrometry) analysis of trace element (strontium and magnesium) incorporation into calcium carbonate provides additional evidence for a shift in CaCO3 polymorphs identified via XRD (xray diffraction) analysis of speleothem AB-2 from Anjohibe Cave, Madgascar. The ICP-MS Sr/Ca data qualitatively supports the Sr/Ca data collected by the XRF core scanner, exhibiting a sharp decrease in value across the identified mineral transition. A corresponding increase in Mg/Ca revealed by the ICP-MS provides further evidence for a change from aragonite to calcite at this location. This mineralogical change occurred between 870-880 CE (+/- 13 years) is nearly concurrent with a shift in [delta]13C isotopes that was identified in previous work on this speleothem and attributed to an ecological shift in dominant photosynthetic pathways (Bums et al 2016). A second, control section was identified as pure calcite by XRD analysis, but revealed Mg/Ca and Sr/Ca ratios characteristic of mineralogical transitions, suggesting that there may have been layers of aragonite that have recrystallized to calcite since deposition.
Download or read book Analysis of Trace Elements for Determining the Stability of Calcite and Aragonite written by J. Eian Harm and published by . This book was released on 1997 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Environmental and Growth Rate Effects on Trace Element Incorporation to Calcite and Aragonite written by Jeremy M. Weremeichik and published by . This book was released on 2016 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: The subsumed work of this dissertation is comprised of three independent but interrelated studies which seek to further the understanding of processes which govern the coprecipitation of trace elements with calcite and aragonite minerals. These studies investigate the effects of: 1) pressure on crystal morphology and trace element incorporation to aragonite; 2) growth rate on uranium partitioning between calcite and fluid; 3) aqueous Mg/Ca on the magnesium partitioning to low-magnesium calcite. The importance of this work is to determine how the environment of formation and growth rate influences the geochemistry of CaCO3 in order to improve existing paleoproxies and develop new ones. In the first study a series of experiments were conducted at 1, 25, 75, 100, and 345 bars of nitrogen – this range covers pressures at the oceanic floor. Aragonite precipitation was induced by the one-time addition of a Na2CO3 solution to an artificial seawater. Results suggest that oceanic floor pressures could affect the crystallization of CaCO3 by altering mineralogical composition and aragonite crystal size. In the second study calcite crystallized from NH4Cl-CaCl2-U solution by diffusion of CO2. The calcite growth rate was monitored by sequential spiking of the calciteprecipitating fluids with REE dopants. The resulting crystals were analyzed using Secondary Ion Mass Spectrometry (SIMS). Results showed that the partitioning of uranium increases with increasing growth rate. Growth entrapment model (GEM) and unified uptake kinetics model (UUKM) explain the obtained data. In the third study CaCO3 precipitated in NaCl solution by continuous addition of CaCl2, MgCl2, and either Na2CO3 or NaHCO3. The Mg/Ca of the fluid was adjusted in an attempt to produce calcite where Mg/Ca would match Mg/Ca in foraminifera shells. It was observed that multiple CaCO3 polymorphs precipitated from fluids at high pH (Na2CO3 doping experiments). This result underscores the potential control of pH and/or supersaturation state on CaCO3 polymorph precipitated from low Mg/Ca solutions. Calcite was the only mineral crystallized at low pH (NaHCO3 doping experiments). It was determined that Mg partition coefficient between calcite and fluid (KMg) negatively correlates with Mg/Ca(Fluid) when it exceeds 0.5 mol/mol; no systematic correlation was observed when 0.05
Download or read book Isotopes in Palaeoenvironmental Research written by Melanie J. Leng and published by Springer Science & Business Media. This book was released on 2006-03-09 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thorough reference shows how stable isotopes can be applied to understanding the palaeoenvironment, with chapters on the interpretation of isotopes in water, tree rings, bones and teeth, lake sediments, speleothems and marine sediments. The book offers detailed advice on calibration, including a multi-proxy approach, using isotope signals from different materials or combined with other palaeoenvironmental techniques, to enhance the reliability of readings.
Download or read book Surface Temperature Reconstructions for the Last 2 000 Years written by National Research Council and published by National Academies Press. This book was released on 2007-01-05 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: In response to a request from Congress, Surface Temperature Reconstructions for the Last 2,000 Years assesses the state of scientific efforts to reconstruct surface temperature records for Earth during approximately the last 2,000 years and the implications of these efforts for our understanding of global climate change. Because widespread, reliable temperature records are available only for the last 150 years, scientists estimate temperatures in the more distant past by analyzing "proxy evidence," which includes tree rings, corals, ocean and lake sediments, cave deposits, ice cores, boreholes, and glaciers. Starting in the late 1990s, scientists began using sophisticated methods to combine proxy evidence from many different locations in an effort to estimate surface temperature changes during the last few hundred to few thousand years. This book is an important resource in helping to understand the intricacies of global climate change.
Download or read book Isotope Methods for Dating Old Groundwater written by International Atomic Energy Agency and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This guidebook provides theoretical and practical information for using a variety of isotope tracers for dating old groundwater, i.e. water stored in geological formations for periods ranging from about 1000 to one million years. Theoretical underpinnings of the methods and guidelines for their use in different hydrogeological environments are described. The guidebook also presents a number of case studies providing insight into how various isotopes have been used in aquifers around the world. The methods, findings and conclusions presented in this publication will enable students and practicing groundwater scientists to evaluate the use of isotope dating tools for specific issues related to the assessment and management of groundwater resources. In addition, the guidebook will be of use to the scientific community interested in issues related to radioactive waste disposal in geological repositories.
Download or read book An Introduction to Archaeological Chemistry written by T. Douglas Price and published by Springer Science & Business Media. This book was released on 2010-10-17 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: Archaeological chemistry is a subject of great importance to the study and methodology of archaeology. This comprehensive text covers the subject with a full range of case studies, materials, and research methods. With twenty years of experience teaching the subject, the authors offer straightforward coverage of archaeological chemistry, a subject that can be intimidating for many archaeologists who do not already have a background in the hard sciences. With clear explanations and informative illustrations, the authors have created a highly approachable text, which will help readers overcome that intimidation. Topics covered included: Materials (rock, pottery, bone, charcoal, soils, metals, and others), Instruments (microscopes, NAA, spectrometers, mass spectrometers, GC/MS, XRF & XRD, Case Studies (Provinience, Sediments, Diet Reconstruction, Past Human Movement, Organic Residues). The detailed coverage and clear language will make this useful as an introduction to the study of archaeological chemistry, as well as a useful resource for years after that introduction.
Download or read book Travertine written by Allan Pentecost and published by Springer Science & Business Media. This book was released on 2005-07-22 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt: uring the spring of 1960, an uncle showed me a ‘petrifying spring’ near Plaxtol in Kent Dwhere twigs had been encased in a calcareous jacket. A twig was collected and having - cently been given I. Evan’s Observer’s Book of Geology by my parents, I found a photograph of another petrifying spring and an explanation of its origin. In those days, Derbyshire was too far for a holiday destination, and I took little further interest until a research studentship with Professor G. E. Fogg became available in 1971. Tony Fogg had recently moved to the University College of North Wales, Bangor and the research was to be into cyanobacterium mats, with fieldwork along the Red Sea coast. The fieldwork never materialised but my interest in algal mats had been aroused. A chance stroll along the Bangor shore revealed beautifully calcified cya- bacterium mats, and Tony generously allowed me to investigate these instead. The old Plaxtol collection was retrieved and yielded abundant cyanobacteria. It became apparent that here was a wealth of information about a rock whose formation was so rapid, that the process could be studied in days rather than years – an exceptional state of affairs. A search of the literature also revealed that the rock, a form of travertine, had other unusual features.
Download or read book Crystals written by Ichiro Sunagawa and published by Cambridge University Press. This book was released on 2007-08-13 with total page 309 pages. Available in PDF, EPUB and Kindle. Book excerpt: How do crystals nucleate and grow? Why and how do crystals form such a wide variety of morphologies, from polyhedral to dendritic and spherulitic forms? These are questions that have been posed since the seventeenth century, and are still of vital importance today both for modern technology, and to understand the Earth's interior and the formation of minerals by living organisms. In this book, Ichiro Sunagawa sets out clearly the atomic processes behind crystal growth, and describes case studies of complex systems from diamond, calcite and pyrite, to crystals formed through biomineralization, such as the aragonite of shells, and apatite of teeth. Essential reading for advanced graduates and researchers in mineralogy and materials science.
Download or read book Introduction to Mineralogy and Petrology written by Swapan Kumar Haldar and published by Elsevier. This book was released on 2020-07-29 with total page 437 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introduction to Mineralogy and Petrology, second edition, presents the essentials of both disciplines through an approach accessible to industry professionals, academic researchers, and students alike. This new edition emphasizes the relationship between rocks and minerals, right from the structures created during rock formation through the economics of mineral deposits. While petrology is classified on the lines of geological evolution and rock formation, mineralogy speaks to the physical and chemical properties, uses, and global occurrences for each mineral, emphasizing the need for the growth of human development. The primary goal is for the reader to identify minerals in all respects, including host-rocks, and mineral deposits, with additional knowledge of mineral-exploration, resource, extraction, process, and ultimate use. To help provide a comprehensive analysis across ethical and socio-economic dimensions, a separate chapter describes the hazards associated with minerals, rocks, and mineral industries, and the consequences to humanity along with remedies and case studies. New to the second edition: includes coverage of minerals and petrology in extra-terrestrial environments as well as case studies on the hazards of the mining industry. Addresses the full scope of core concepts of mineralogy and petrology, including crystal structure, formation and grouping of minerals and soils, definition, origin, structure and classification of igneous, sedimentary and metamorphic rocks Features more than 250 figures, illustrations and color photographs to vividly explore the fundamental principles of mineralogy and petrology Offers a holistic approach to both subjects, beginning with the formation of geologic structures that is followed by the hosting of mineral deposits and the exploration and extraction of lucrative, usable products that improve the health of global economies Includes new content on minerals and petrology in extraterrestrial environments and case studies on hazards in the mining industry
Download or read book Studies of Cave Sediments written by Ira D. Sasowsky and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt: John E. Mylroie and Ira D. Sasowsky' Caves occupy incongruous positions in both our culture and our science. The oldest records of modem human culture are the vivid cave paintings from southern France and northern Spain, which are in some cases more than 30,000 years old (Chauvet, et ai, 1996). Yet, to call someone a "caveman" is to declare them primitive and ignorant. Caves, being cryptic and mysterious, occupied important roles in many cultures. For example, Greece, a country with abundant karst, had the oracle at Delphi and Hades the god of death working from caves. People are both drawn to and mortified by caves. Written records ofcave exploration exist from as early as 852 BC (Shaw, 1992). In the decade of the 1920's, which was rich in news events, the second biggest story (as measured by column inches of newsprint) was the entrapment of Floyd Collins in Sand Cave, Kentucky, USA. This was surpassed only by Lindbergh's flight across the Atlantic (Murray and Brucker, 1979).
Download or read book Encyclopedia of Caves and Karst Science written by John Gunn and published by Routledge. This book was released on 2004-08-02 with total page 1971 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Encyclopedia of Caves and Karst Science contains 350 alphabetically arranged entries. The topics include cave and karst geoscience, cave archaeology and human use of caves, art in caves, hydrology and groundwater, cave and karst history, and conservation and management. The Encyclopedia is extensively illustrated with photographs, maps, diagrams, and tables, and has thematic content lists and a comprehensive index to facilitate searching and browsing.
Download or read book Micro XRF Studies of Sediment Cores written by Ian W. Croudace and published by Springer. This book was released on 2015-07-21 with total page 668 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume presents papers on the use of micro-XRF core scanners in palaeoenvironmental research. It contains a broad ranging view of instrument capability and points to future developments that will help contribute to higher precision elemental data and faster core analysis. Readers will find a diverse range of research by leading experts that have used micro-XRF core scanners in a wide range of scientific applications. The book includes specific application papers reporting on the use of XRF core scanners in a variety of marine, lacustrine, and pollution studies. In addition, coverage also examines practical aspects of core scanner usage, data optimisation and data calibration and interpretation. In a little over a decade, micro-XRF sediment core scanners have made a substantive contribution to palaeoenvironmental research. Their impact is based on their ability to rapidly, non-destructively and automatically scan sediment cores. Not only do they rapidly provide important proxy data without damaging samples, but they can obtain environmental data at decadal, annual and even sub-annual scales. This volume will help both experienced and new users of these non-destructive core scanners take full advantage of one of the most powerful geochemical screening tools in the environmental scientist's toolbox.
Download or read book Lectures in Isotope Geology written by E. Jäger and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 507 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our colleagues from the French-speaking parts of Switzerland - the Suisses romands - and above all the committee of the 3rd Cycle, e Earth Sciences (3 Cycle, Sciences de la Terre) honored us by asking us to give a course on Isotope Geology for the year 1977. The course, entitled Evaluation et Interpretation des Donnees Isotopiques (eval uation and Interpretation of Isotopic Data), was intended to inform earth scientists, graduate and postgraduate, from the western Swiss Universities on the subject of Isotope Geology. Such courses usually consist of two parts: lectures and excursions. Thus, in March 1977, we gave such a two-week course at the Miner alogical Institute of the University of Berne. The first week was devoted essentially to the methods of dating, the second week to the behavior of stable isotopes. In July 1977, on the occasion of an excursion to the Central and Western Alps, we were able to demonstrate our results. Guest professors were invited to make contributions to the course.
Download or read book Preliminary Determination of Epicenters written by and published by . This book was released on 2006 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The New Geology written by George McCready Price and published by . This book was released on 1923 with total page 742 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Past Climate Variability through Europe and Africa written by Richard W. Battarbee and published by Springer Science & Business Media. This book was released on 2007-11-06 with total page 653 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on two complementary time-scales, the Holocene (approximately the last 11,500 years) and the last glacial-interglacial cycle (approximately the last 130,000 years) to synthesize evidence of climate variability at the regional and continental scale across Europe and Africa. This is the first examination of historical climate variations at such a scale, and thus sets a benchmark for future research.
