Interpretation of geochemical data

Year Three Complete analysis of trace elements by ICP-MS at Lawrence University analysis of major elements by XRF at Macalester College (up to 100 samples) determination of Sr, Nd, and Pb isotopic ratios of a selection of Wolf and Darwin samples by TIMS at Cornell (up to 30 samples). Interpretation of geochemical data, modeling of melting parameters. Presentation of results at Fall AGU meeting by undergraduate student(s). Preparation for fieldwork. 

It is not clear what is the best model to describe the variability of soil metal concentrations. Ahrens (1954, 1966) has proposed that the distribution of elements in igneous rocks approximates to a log-normal distribution. This model does not necessarily apply to soils but the available evidence suggests it may. Its applicability underlies the interpretation of geochemical data in mineral exploration. 

Le Maitre R.W., 1982, Numerical petrology statistical interpretation of geochemical data, Elsevier, Amsterdam. 

Good introductions to factor analysis were given by Koch and Link, Klovan and Joreskog and co-workers. Nichol and co-workers were pioneer practitioners in the use of factor analysis for the interpretation of geochemical data and wrote a milestone paper on its application to stream sediments. ... 

Characteristics that complicate the interpretation of geochemical and radiometric data for uranium deposits include 1) variable oxidation state of uranium and associated elements 2) the variety of aqueous species possible 3) the tendency for soluble uranium and... 

Arnorsson, S. 1996. Interpretation of Geochemical and Isotopic Data from Well Discharges in the Momotombo Geothermal Field, Nicaragua With Recommendations on Monitoring Studies. International Atomic Energy Agency Report (Project NIC/8/008-03), May 1996, 24 pp. 

Ducea MN, Saleeby JB (1996) Buoyancy sources for a large unrooted mountain range, the Sierra Nevada, California Evidence from xenolith thermobarometry. J Geophys Res 101 8229-8241 Ehlers TA (2005) Crustal thermal processes and the interpretation of thermochronometer data. Rev Mineral Geochem 58 315-350... 

Spatial interpolation of geochemical data has greatly improved the quality of geochemical data presentation and subsequent interpretation over the past 20 years or so. 

Mathematical treatment of geochemical data cannot, of course, improve their quality but does ensure proper interpretation of the data and the procedures used to obtain them. Multivariate analysis can bring a mass of data into manageable form and reveal relationships between variables which graphical analysis would not (Middleton, 1963). 

Emphasis has also been placed on the fundamental principles of surface seepage, and the interpretation of the data. It is the opinion of the authors that the overall acceptance of microseep technology in the West has been hindered not only by the emphasis and success of seismic methods but also because of the lack of a comprehensive and public surface geochemistry database. There are, by comparison, more publications on geochemical survey data and basic concepts in the Soviet and Russian literature. As a consequence, many of our discussions rely on experience gained in the private sector in the West, supplemented by literature published in the East. 

Milltown Supefund Site supplemental data interpretation of geochemical release mechanisms and arsenic fate and transport Helena, Montana, USEPA. 

Understanding the rate at which fluids move and mix in the subsurface is crucial for correctly interpreting reservoir geochemical data, and is particularly important for extracting business value from such data. One of the main ways in which reservoir fluid data (here including fluid pressure, fluid physical properties, fluid chemical properties and fluid contacts) are applied is in the detection of reservoir compartmentalization, something that is key for optimizing reservoir development. 

It must be noted, however, that whilst the correlation matrix is a very useful device and correlation coefficients are useful statistical descriptors, we must be cautious about their use in geochemistry because of the very special nature of geochemical data (see Section 2.6). As I shall show more fully below, the value of a correlation coefiident may not be in doubt but the petrogenetic meaning ascribed to that value is open to interpretation. 

Shibue, Y. (1991) Mixing diagrams for hydrothermal solutions Applications to interpretation of fluid inclusion data of hydrothermal ore deposits in Japan. Geochem. J., 25, 75-93. 

PCs with high eigenvalues are assumed to best represent the geochemical variability and characteristics of the data. Components 4 and higher returned Eigenvalues below 1.0 and were excluded from further interpretation, as discussed by Mandal et al. (2008). 

This study describes the results of the formation water monitoring and the interpretation of the physical and geochemical processes from that data,... 

Detailed interpretation of kinetic test data collected for environmental purposes has allowed criteria for ground and surface water geochemical exploration to be selected. Parameters predicted from kinetic testing to be anomalous in both ground and surface waters were observed to occur reflecting the presence of both molybdenum mineralization and natural acid rock drainage. Kinetic testing is very expensive and careful use of the acquired... 

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