Using major element data

Roser, B.P. Korsch, R.J. 1988. Provenance signatures of sandstone-mudstone suites determined using discriminant function analysis of major-element data. Chemical Geology, 67, 119-139. 

A normal percentage array of major element data is described by Chayes (1960) as closed (Aitchison, 1986 and elsewhere, uses the term composition ) and a... 

This chapter will examine the ways in which major element data axe used in geochemistry. The discussion will be restricted to the ten elements traditionally listed as oxides in a major element chemical analysis — Si, Ti, Al, Fe, Mn, Mg, Ca, Na, K and P. Geochemists make use of major element data in three principal ways — in rock classification, in the construction of variation diagrams and as a means of comparison with experimentally determined rock compositions, whose conditions of formation are known. Each of these uses will be discussed in a separate section of this chapter. In addition, major elements are used, often together with trace elements, in the identification of the original tectonic setting of igneous and some sedimentary rocks. This topic will be discussed in Chapter 5. 

With the advent of automated XRF analysis, most geochemical investigations produce a large volume of major element data. Thus, increasingly it is both useful and in some cases necessary to attempt to classify rocks on the basis of their chemical composition. This section reviews the classification schemes in current use... 

The REE data, combined with alteration minerals and concentration of major elements in hydrothermally altered rocks, could be used to reconstruct the structure and evolution of a submarine geothermal system accompanied by Kuroko mineralization (Shikazono, 1999a). 

Table 3 describes the main parts of an environmental risk assessment (ERA) that are based on the two major elements characterisation of exposure and characterisation of effects [27, 51]. ERA uses a combination of exposure and effects data as a basis for assessing the likelihood and severity of adverse effects (risks) and feeds this into the decision-making process for managing risks. The process of assessing risk ranges from the simple calculation of hazard ratios to complex utilisation of probabilistic methods based on models and/or measured data sets. Setting of thresholds such as EQS and quality norms (QN) [27] relies primarily on... 

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