Download or read book Preparation and Certification of IRMM 3636 IRMM 3636a and IRMM 3636b written by and published by . This book was released on 2008 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Isotope reference materials IRMM-3636 was prepared by gravimetrically mixing of solutions from highly enriched 99.96% 233U (IRMM-3630) and highly enriched 99.97% 236U (IRMM-3660) in order to obtain an isotopic ratio n(233U)/n(236U) close to unity. IRMM-3636a and IRMM-3636b were prepared from IRMM-3636 by gravimetrical dilution. The primary solution, IRMM-3636 is for the time being not yet available for external users. The certified isotope content values for IRMM-3636a of 4.27988(54)Å"0-7 mol U per g of solution and for IRMM-3636b of 2.21802(61)Å"0-8 mol U per g of solution and the certified isotope amount ratios have been established by mass metrology, subsequently the primary solution IRMM-3636 was verified by isotope mass spectrometry. The methodology used in the preparation and certification was similar to that of comparable uranium mixtures made in the past. The uncertainties contributing to the final uncertainties of the isotopic ratios are the weighing errors, the measured impurities in each starting material, the stoichiometry of the oxides and the isotopic abundances of each of the starting materials. The method for the preparation and mixing is described and the certification and verification procedures are reported. Verification of IRMM-3636 was performed by TRITON TIMS measurements using Faraday collectors and secondary electron multiplier in combination with an RPQ energy filter for improved abundance sensitivity. The results agreed well with the certified values obtained from the mixing calculations. By mixing the n(233U)/n(236U) double spike with a sample and applying internal mass fractionation correction, the n(235U)/n(238U) ratio of a given sample can be determined with the highest possible accuracy. The Isotopic Reference Materials IRMM-3636a and IRMM-3636b are part of a systematic IRMM programme to supply Isotopic Reference Materials of various isotopes at different concentrations The Isotopic Reference Material is supplied in a sealed quartz ampoule containing 1 mL of a 1 M nitric acid solution

Download or read book Preparation and Certification of IRMM 1000a 20 Mg and IRMM 1000b 50 Mg written by and published by . This book was released on 2015 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes the production and certification of IRMM-1000a and IRMM-1000b, uranium reference materials certified for the production date based on the 230Th/234U radiochronometer, which corresponds to the last chemical separation, i.e. the removal of any 230Th from the material to the maximum extent achievable. The starting material was low-enriched uranium with a relative mass fraction, m(235U)/m(U) of 3.6 %. The targeted completeness for the last chemical separation of the 230Th decay product from its parent nuclide 234U was achieved. The certified production date was assigned following ISO Guide 34:2009. The between unit-homogeneity and the stability of the certified value were assessed in accordance with ISO Guide 35:2006. The uncertainty of the certified value was estimated in compliance with the Guide to the Expression of Uncertainty in Measurement (GUM) and includes uncertainties related to characterisation, possible inhomogeneity and instability. The material is mainly intended for calibration of methods, quality control, and assessment of method performance with isotope mass spectrometry and radiometry techniques. As any reference material, it can also be used for control charts or validation studies. The certified reference material is available in two sizes: 20 mg (IRMM-1000a) and 50 mg uranium (IRMM-1000b) as dried uranyl nitrate in screw-cap TeflonÒ (PFA) vials.

Download or read book Uranium series Geochemistry written by Bernard Bourdon and published by Walter de Gruyter GmbH & Co KG. This book was released on 2018-12-17 with total page 676 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volume 52 of Reviews in Mineralogy and Geochemistry updates our knowledge of U-series geochemistry, offer an opportunity for non-specialists to understand its basic principles, and give us a view of the future of this active field of research. In this volume, for the first time, all the methods for determining the uranium and thorium decay chain nuclides in Earth materials are discussed. It was prepared in advance of a two-day short course (April 3-4, 2003) on U-series geochemistry, jointly sponsored by GS and MSA and presented in Paris, France prior to the joint EGS/AGU/EUG meeting in Nice.

Download or read book The Jehol Biota written by Miman Zhang and published by . This book was released on 2003 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Applications of Microanalytical Techniques to Understanding Mineralizing Processes written by Michael A. McKibben and published by . This book was released on 1998 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Geological Record of Neoproterozoic Glaciations written by Emmanuelle Arnaud and published by Geological Society of London. This book was released on 2011 with total page 750 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, interest in Neoproterozoic glaciations has grown as their pivotal role in Earth system evolution has become increasingly clear. One of the main goals of the IGCP Project number 512 was to produce a synthesis of newly available information on Neoproterozoic successions worldwide. This Memoir consists of a series of overview chapters followed by site-specific chapters. The overviews cover key topics including the history of research on Neoproterozoic glaciations, identification of glacial deposits, chemostratigraphic techniques and datasets, palaeomagnetism, biostratigraphy, geochronology and climate modelling. The site specific chapters include reviews of the history of research on these rocks and up-to-date syntheses of the structural framework, tectonic setting, palaeomagnetic & geochronological constraints, physical, biological, and chemical stratigraphy, and descriptions of the glaciogenic and associated strata, including economic deposits.

Download or read book Geochemistry of Sedimentary Carbonates written by J.W. Morse and published by Elsevier. This book was released on 1990-08-27 with total page 725 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the more basic aspects of carbonate minerals and their interaction with aqueous solutions; modern marine carbonate formation and sediments; carbonate diagenesis (early marine, meteoric and burial); the global cycle of carbon and human intervention; and the role of sedimentary carbonates as indicators of stability and changes in the Earth's surface environment. The selected subjects are presented with sufficient background information to enable the non-specialist to understand the basic chemistry involved. Tested on classes taught by the authors, and approved by the students, this comprehensive volume will prove itself to be a valuable reference source to students, researchers and professionals in the fields of oceanography, geochemistry, petrology, environmental science and petroleum geology.

Download or read book Continental Shelf Limits written by Peter J. Cook and published by Oxford University Press. This book was released on 2000-10-19 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt: Article 76 of the United Nations Convention on the Law of the Sea lays down the rules and regulations governing claims to a continental shelf beyond 200 nautical miles for the 130 coastal States and entities that have ratified or acceded to it. This book is designed to help those coastal States implement the provisions of Article 76, covering the technical issues involved and explaining the interface between the legal concepts contained within the article. It covers all aspects that will have to be considered by a coastal State if it wishes to make a claim under the Convention, including the characteristics of continental margins, distance determination, bathymetric data collection. geological and geophysical techniques, and boundary conditions.

Download or read book Subsurface Geology of a Prograding Carbonate Platform Margin Great Bahama Bank written by Robert N. Ginsburg and published by SEPM (Society for Sedimentary Geology). This book was released on 2001 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume will be of special interest to carbonate sedimentologists, geochemists, petroleum geologists, engineers, and seismologists. It addresses fundamental aspects of prograding carbonate platforms in a Neogene example from Great Bahama Bank. A remarkable seismic profile, which imaged the prograding margin, provided the seismic stratigraphic framework. Two continuouslycored and logged borings on the profile produced the ground truth for testing and characterizing processes: lithologies and ages of sequence boundaries; influence of sea level fluctuations on progradation, controls on impedance contrasts in carbonates; fluid flow through the submerged margin; log responses of different lithologies; and the origin, ages and depositional environments of the platform top and prograding clinothems. The new findings on diagenesis are of special interest, including complete mineral stabilization in seawater, early burial dolomitization related to sequence boundaries and how diagenesis controls sonic velocity and permeability.

Download or read book Stable Isotopes in High Temperature Geological Processes written by John W. Valley and published by Walter de Gruyter GmbH & Co KG. This book was released on 2018-12-17 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volume 16 of Reviews in Mineralogy inroduces to high-temperature stable isotope geochemistry and should provide an entry into the pertinent literature, as well as some understanding of the basic concepts and potential applications. The first three chapters focus on the theory and experimental data base for equilibrium, disequilibrium, and kinetics of stable isotope exchange reactions among geologically important minerals and fluids. The fourth chapter discusses the primordial oxygen isotope variations in the solar system prior to formation of the Earth, along with a discussion of isotopic anomalies in meteorites. The fifth chapter discusses isotopic variations in the Earth's mantle and the sixth chapter reviews the variations in the isotopic compositions of natural waters on our planet. In Chapters 7, 8, 9 and 10, these isotopic constraints and concepts are applied to various facets of the origin and evolution of igneous rocks, bringing in much material on radiogenic isotopes as well, because these problems require a multi-dimensional attack for their solution. In Chapters 11 and 12, the problems of hydrothermal alteration by meteoric waters and ocean water are considered, together with discussions of the physics and chemistry of hydrothermal systems and the 18O/16O history of ocean water. Finally, in Chapters 13 and 14, these concepts are applied to problems of metamorphic petrology and ore deposits, particularly with respect to the origins of the fluids involved in those processes.

Download or read book Use of Proxies in Paleoceanography written by Gerhard Fischer and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 768 pages. Available in PDF, EPUB and Kindle. Book excerpt: Paleoceanographic proxies provide infonnation for reconstructions of the past, including climate changes, global and regional oceanography, and the cycles of biochemical components in the ocean. These prox ies are measurable descriptors for desired but unobservable environmental variables such as tempera ture, salinity, primary productivity, nutrient content, or surface-water carbon dioxide concentrations. The proxies are employed in a manner analogous to oceanographic methods. The water masses are first characterized according to their specific physical and chemical properties, and then related to particular assemblages of certain organisms or to particular element or isotope distributions. We have a long-standing series of proven proxies available. Marine microfossil assemblages, for instance, are employed to reconstruct surface-water temperatures. The calcareous shells of planktonic and benthic microorgan isms contain a wealth of paleoceanographic information in their isotopic and elemental compositions. Stable oxygen isotope measurements are used to detennine ice volume, and MglCa ratios are related to water temperatures, to cite a few examples. Organic material may also provide valuable infonnation, e. g. , about past productivity conditions. Studying the stable carbon isotope composition of bulk organic matter or individual marine organic components may provide a measure of past surface-water CO 2 conditions within the bounds of certain assumptions. Within the scope of paleoceanographic investigations, the existing proxies are continuously evolving and improving, while new proxies are being studied and developed. The methodology is improved by analysis of samples from the water column and surface sediments, and through laboratory experiments.

Download or read book The Changing Carbon Cycle written by John R. Trabalka and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 615 pages. Available in PDF, EPUB and Kindle. Book excerpt: The United States Government, cognizant of its responsibilities to future generations, has been sponsoring research for nine years into the causes, effects, and potential impacts of increased concentrations of carbon dioxide (C0 ) in the atmosphere. Agencies such as the National Science Foun 2 dation, National Oceanic and Atmospheric Administration, and the U.S. Department of Energy (DOE) cooperatively spent about $100 million from FY 1978 through FY 1984 directly on the study of CO • The DOE, as the 2 lead government agency for coordinating the government' s research ef forts, has been responsible for about 60% of these research efforts. William James succinctly defined our purpose when he stated science must be based upon " ... irreducible and stubborn facts." Scientific knowledge can and will reduce the present significant uncertainty sur rounding our understanding of the causes, effects, and potential impacts of increasing atmospheric CO2• We have come far during the past seven years in resolving some underlyinig doubts and in narrowing the ranges of disagreement. Basic concepts have become less murky. Yet, much more must be accomplished; more irreducible and stubborn facts are needed to reduce the uncertainties so that we can improve our knowledge base. Uncertainty can never be reduced to zero. However, with a much improved knowledge base, we will be able to learn, under stand, and be in a position to make decisions.

Download or read book Carbonates written by Richard J. Reeder and published by Walter de Gruyter GmbH & Co KG. This book was released on 2018-12-17 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volume 11 of Reviews in Mineralogy attempts to synthesize our present understanding of certain aspects of the mineralogy and chemistry of the rock-forming carbonates. This review follows, by ten years, a major assessment of (sedimentary) carbonate minerals by Lippmann (1973). There is only minor overlap of subject material, and I hope that this difference reflects fairly how this field has developed. In this volume, some of the papers are general (i.e., those addressing crystal chemistry and phase relations), and they provide overviews of a fundamental nature and are of interest to many. Others are more specialized in coverage and generally reflect the different approaches used in carbonate geochemistry. The final chapter introduces transmission electron microscopy, a relatively new and powerful technique for mineralogical research that has great potential in carbonate research.

Download or read book Global Events and Event Stratigraphy in the Phanerozoic written by Otto H. Walliser and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 455 pages. Available in PDF, EPUB and Kindle. Book excerpt: The existence of rapid and even catastrophic turnovers within the Phanerozoic ecosystems has been discussed controversially for more than 170 years. Since 1980 this discussion has become even more intensive after the hypothesis of Alvarez, explaining the end-Cretaceous mass extinction as the result of a huge asteroid impact on the Earth. This theory stimulated several thousand papers and is still controversial. The international research programme on "Global Biological Events in Earth History" attempts to bring the discussion back to the facts by using multidisciplinary investigations of the major Phanerozoic events. The results of an international group of experts are presented giving a wealth of information and a thorough discussion of the causes of the various global events.

Download or read book An Australian Phanerozoic Timescale written by Gavin C. Young and published by Oxford University Press, USA. This book was released on 1996 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gives a new global perspective on the Phanerozoic timescale, by bringing together extensive Australian and overseas research on biostratigraphy, geochronology, and magnetostratigraphy. For the first time, correlations are established between Australian and European biozonal schemes for the entire Phanerozoic, by integrating local and international biozones, isotopic ages, and magnetic polarity intervals. Tie points are based on tightly constrained isotopic and biostrastigraphic ages, and this is the first compilation for the whole of the Phanerozoic to apply results from the latest isotopic dating techniques, including the high resolution ion microprobe (SHRIMP) and variants of the (superscript 40)Ar/(superscript 39)Ar method. These have radically rescaled some parts of the geological column. An Australian Phanerozoic Timescale gives the essential framework for resource exploration, geologic modelling, and reconstruction of past environments and land-sea configurations during the last 545 million years of earth history.

Download or read book Continental Scientific Drilling written by Ulrich Harms and published by Springer. This book was released on 2010-10-14 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume provides a review and synthesizes the accomplishments of the past decade of the International Continental Scientific Drilling Program. More importantly, it defines opportunities for scientific advancement through future drilling projects addressing a broad range of disciplines in the Earth Sciences. In addition there is a review of all past projects that were supported by the ICDP, as well as of technical aspects associated with continental drilling.

Download or read book Cambrian Neogene Plate Tectonic Maps written by Jan Golonka and published by . This book was released on 2000 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt: