On typomorphic indicator elements of the Semiluzhenskoye antimony ore occurrence (Tomsk Region)
Abstract Generated abstract
This paper evaluates typomorphic indicator elements for prospecting antimony and mercury mineralization at the Semiluzhenskoye ore occurrence in Tomsk Region. Using semiquantitative spectral analyses of about 2,000 rock samples from drill cores, outcrops, and areal sampling, the authors applied rank correlation methods suited to non-normal analytical data to assess associations among ore and trace elements. The study identifies barium, arsenic, molybdenum, strontium, mercury, antimony, and to a lesser extent zinc as useful prospecting indicators, with the strongest reported relationships involving antimony with barium and molybdenum, mercury with barium, and inverse relations of strontium with mercury and antimony.
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ON TYPOMORPHIC INDICATOR ELEMENTS OF THE SEMILUZHENSKOYE ANTIMONY ORE OCCURRENCE
(TOMSK REGION)
G. M. IVANOVA, G. N. APUFPIEVA
(Presented by the scientific seminar of the Department of Petrography)
Experience in the study of antimony–mercury deposits has shown that, in the course of prospecting, typomorphic indicator elements are of great assistance (V. P. Fedorchuk, 1964; N. A. Ozerova, 1962). But at each specific deposit the regular relationship between these elements and the ore components manifests itself differently: in some cases it is clearly expressed for the given elements, in others more weakly. In view of this, using the method of mathematical statistics, we had to identify in the area of the Semiluzhenskoye antimony ore occurrence the most reliable complex of indicator elements. For this purpose, up to 2,000 rock samples were subjected to spectral analysis for all the elements mentioned above, both from drill cores and from outcrops. After this, the corresponding calculations were carried out.
Since the analysis of the samples was performed by a semiquantitative spectral method, and the data of such an analysis do not obey a normal (lognormal) law, we had to use the procedure for calculating the coefficient of so-called ordinal, or rank, correlation, which in the final analysis made it possible to draw the definite conclusions set forth below.
As a result of calculating rank correlation for samples from boreholes 17 and 29 (they were sampled most completely), as well as from the materials of areal sampling (outcrops and by means of a prospecting pick), certain coefficients of rank correlation were obtained. The coefficient was determined from the nomogram of Mitchfield and Wilcoxon. Then, from the corresponding table, a direct dependence was established for the following elements using the rank-correlation coefficient: mercury—barium (correlation coefficient +0.37, probability 95%); antimony—barium (correlation coefficient +0.50, probability 99%); antimony—molybdenum (correlation coefficient +0.48, probability 99%); inverse dependence: mercury—strontium (correlation coefficient +0.51, probability 99%), antimony—strontium (correlation coefficient +0.46, probability 98%). A direct dependence with a somewhat smaller degree of probability was established for the following pairs of elements: antimony—arsenic (correlation coefficient +0.29, probability 74%); mercury—molybdenum (correlation coefficient +0.24, probability 62%); mercury—antimony (correlation coefficient
+0.27, probability 70%); mercury—zinc (correlation coefficient +0.23, probability 62%). The relationship between antimony and mercury is manifested more strongly in analyses of heavy fractions than in analyses of rock samples, as V. P. Fedorchuk also indicated in his studies.
No relationship was found between antimony and copper, mercury and nickel, mercury and vanadium, or antimony and nickel. Rather contradictory and unreliable data were obtained for the following pairs: antimony—lead, mercury—copper.
From the foregoing, the following conclusions may be drawn: the elements barium, arsenic, molybdenum, strontium, mercury, antimony, and, to a lesser extent, zinc may serve as prospecting indicator elements for antimony–mercury mineralization in the area of the Semiluzhenskoye ore occurrence.