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Metallogenic Fingerprints of the Tectonic Domains of China
Author(s) -
WANG Yang
Publication year - 2014
Publication title -
acta geologica sinica ‐ english edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.444
H-Index - 61
eISSN - 1755-6724
pISSN - 1000-9515
DOI - 10.1111/1755-6724.12367_23
Subject(s) - beijing , china , library science , citation , chinese academy of sciences , directory , history , computer science , geology , archaeology , operating system
Tectonic domains are metallogenically distinct in that their mineral deposits contain different mixtures of metallic elements from domain to domain (de Wit and Thiart, 2005). Metallogenic provinces represent regional geochemical heterogeneities in the crust, evidence for which remains encoded on each province as unique metallogenic “fingerprints”. The geological and mineral deposit data used for this study are compiled from the atlases of the China Geological Map and the Metal Resources of China. According to their geochemical affinities, six element groups were selected for analyses. The six element groups, and the total number of deposits in which these groups occur on each tectonic domain of China continent are tabulated. In total there are 3572 deposits spread over six tectonic domains of China. The metallogenic fingerprints of fragments of continental crust can be calculated through their spatial association with a combination of six element groups (e.g., Au, CrNiPGETi, CuPbZnBa, SnSb, W, and UThREE), using the spatial coefficient (rij) proposed by de Wit and Thiart (2005). The spatial coefficient (rij) represents the proportion of deposits that occur in the specified tectonic domain per unit area. The value of the spatial coefficient ranges from 0 to infinity; it is equal to 1 if there is no spatial association between a tectonic domain and an element group. There is a positive association between mineral j and tectonic domain i for values of natural log of rij, ln(rij) > 0; and a negative association was represented by ln(rij) < 0. The mineralization in the less-developed regions, especially in western China, may not be adequately represented in the atlases of metal resources. This problem is tackled by weighting the spatial coefficient, with an “exploration index”. The definition and calculation method of “exploration index” and “weighted” spatial coefficient (rij) are taken from Thiart and de Wit (2006). In this study, the population density data from National Bureau of Statistics of China database are estimated to calculated exploration index using the Southeastern China as a benchmark (e.g., the SE China has an exploration index of 1). The interpretation of rij is the same as in that of the unweighted spatial coefficient. Positive values of ln (rij) is a measure of the positive spatial association between the i tectonic domain and the j element group, and negative values of ln(rij) is a measure of the negative association.