نتایج جستجو برای: geochemical tracers

تعداد نتایج: 20295  

Abstract Most conventional statistical methods aiming at defining geochemical concentration thresholds for separating anomalies from background have limited effectiveness in areas with complex geological settings and variable lithology. In this paper, median+2MAD as a method of exploratory data analysis (EDA) and concentration-area (C-A) fractal model as two effective approaches in separation g...

2002
A. S. Barabash

A comparison is made of the probability of the process of two neutrino double beta decay for Se in direct (counter) and geochemical experiments. It is shown that the probability is systematically lower in geochemical experiments, which characterize the probability of ββ(2ν) decay a few billions years ago. The experimental data for Te are also analyzed. It is shown that geochemical measurements ...

Journal: :Geochemistry Geophysics Geosystems 2022

Earth's mantle nitrogen (N) content is comparable to that found in its N-rich atmosphere. Mantle N has been proposed be primordial or sourced by later subduction, yet origin not elucidated. Here we model partitioning during the magma ocean stage following planet formation and subsequent cycling between surface over Earth history using argon (Ar) isotopes as tracers. The model, constrained Ar, s...

2005
Katrin Grünfeld

Geochemical mapping programs carried out by the Geological Survey of Sweden (SGU) have generated large databases containing information on the concentrations of chemical elements in rocks, surface sediments and biogeochemical materials. Regional geochemical data being imprecise, multivariate, spatially auto-correlated and non-normally distributed pose specific problems to the choice of data ana...

Journal: :Environmental pollution 2006
G B Pasternack K J Brown

The geochemical history of an upper deltaic plain pending tidal wetland restoration was reconstructed to assess remobilization of redox-sensitive constituents in sediment, identify depositional processes promoting geochemical retention, and determine the extent of contamination with Hg, As, Pb, Cu, and Zn. Three 12-14-m sediment cores were analyzed for bulk sediment geochemistry using ICP-AES. ...

2007
Kathleen S. Smith

This report presents some strategies to predict metal mobility at mining sites. These strategies are based on chemical, physical, and geochemical information about metals and their interactions with the environment. An overview of conceptual models, metal sources, and relative mobility of metals under different geochemical conditions is presented, followed by a discussion of some important phys...

Journal: :Geochemical Transactions 2006
Martin AA Schoonen Ken B Anderson Scott A Wood

Editorial Geochemical Transactions, the first online-only journal in geochemistry and environmental chemistry, is now the first major open access journal in this subject area. All issues of Geochemical Transactions, including the back content, will be fully and permanently available online to all, without a subscription charge. Copyright of all future articles will be retained by the authors. G...

Introduction: Reduction of sediment supply requires the implementation of soil conservation and sediment control programs in the form of watershed management plans. Sediment control programs require identifying the relative importance of sediment sources, their quantitative ascription and identification of critical areas within the watersheds. The sediment source ascription is involves two...

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