Geochemical data evaluation

Grunsky, E.C. 2007. Geochemical data evaluation and interpretation. In Coker, W.B. (ed) Exploration Geochemistry - Basic Principles and Concepts, Workshop 2, Exploration 07, Toronto, 13-17. 

RoUinson H. (1993) Using Geochemical Data Evaluation, Presentation, Interpretation. Longman, Singapore. 

Geochemical data consist of analyses of 485 pond sediment samples collected as part of the 1970s National Uranium Resource Evaluation (NURE) program (http //tin.er.usgs.gov/geochemO. 

This volume covers ongoing research and, thus, leaves many questions unanswered and many problems unsolved. The geochemistry of disposed radioactive wastes involves many complex issues that will require years of additional research to resolve. High-priority problems include integration of geochemical data with computer models of chemical interaction and transport, definition of environmental conditions that affect the behavior of radionuclides at specific disposal sites, evaluation of complex formation of dissolved radionuclides with inorganic and organic complexants, and determination of radionuclide solubilities in natural waters. 

Comparison of the physicochemical and geochemical data on the forms of transport and conditions of deposition of iron and silica with modern ideas concerning the particulars of sedimentation in the Precambrian makes it possible to evaluate critically and to some extent place constraints on the numerous versions of existing genetic hypotheses. After such reexamination, the scheme of formation for the Precambrian iron-formations that is best substantiated from the physicochemical standpoint can be presented. 

Hoffman, J. D., and Buttleman, K. (1994). National geochemical data base national uranium resource evaluation data for the conterminous United States, with MAPPER display software by R. A. Ambroziak and MAPPER documentation by C. A. Cook. U.S. Geological Survey digital data series DDS-0018-A CD-RQM. 

The evaluation of the geochemical data obtained from the exploration can be substantially speeded up by means of a suitable computation system. 

Table 20.4 presents the partition and transformation processes known to occur in the near-surface environment along with the special factors that should be considered when evaluating data in the context of the deep-well environment. Geochemical processes affecting hazardous wastes in deep-well environments have been studied much less than those occurring in near-surface environments (such as soils and shallow aquifers). Consequently, laboratory data and field studies for a particular substance may be available for near-surface conditions, but not for deep-well conditions. 

Government organisations are well placed to generate regional geochemical datasets, in that they are not subject to the time and cost constraints which form part of mineral exploration legislation. These data are usually multi-element and include QA-QC data which mean the data are well suited to multi-commodity exploration and evaluation in terms of data quality. The... 

The Koongarra U deposit in the Northern Territory of Australia has been studied to evaluate the processes and mechanisms involved in the geochemical alteration of the primary ore zone, and to model the formation of the secondary U ore zone and dispersion fan (Duerden 1991 Duerden Airey 1994). Studies of the distribution of the U in the dispersion fan (Murakami et al. 1991) have provided data on the fixation of U leached from the primary ore deposit. Their work has shown that, for this system, fractures are not only preferential pathways for ground-water movement but also contain secondary minerals with high sorption capacity for elements such as U. Even in the monsoonal climate, in which this deposit is located, a significant proportion of the uranium has not been released from the vicinity of the primary ore body. 

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