Geochemical classification of the elements based on the ratios of their contents in four natural systems - the Sun - O·, chondrites - Ch, basalts - v, in clays and shales - c (Shcherbakov, 1979, 1994, 1995) allows to reveal some regularities in their ore concentrating.
The non volatile elements (Ch/O·>>1) are devided into two types : the femic (f=c/v<1) and the sialic (s=c/v>1). Each of them consist of heterophyle elements (h) and oxiphyle (o) ones, groupped in sequences according to the order reducing of concentrating of elements in ore deposits (shown below). The degree of element concentrating is normed by the average between v and c and is reflected with amount of signs (both points and commas near to the element sign). The point means the order of concentrating in own minerals and the comma - in the isomorphed form. Left position of signs shows the rest concentrating of elements in root face and the right one - in an apical part of ore hydrothermal system.
fh - /Hg::/.Au::/.Co:./.Zn:./.Cu:/,,Re,/;Pd/:Pt/;Rh/;Ru/;Os
fo - /.:Cr/:Mn/Na:/.P:/.V:/,Sr;/.Ca./.Mg/.Ti/,Sc
sh - /.Sb::/Te:./Bi:./Ag:./Pb:./Tl,,/In,,/Cd,,/Ga,,/.S:/:Sn:
/Eu;/Gd;/Tb; /Dy,/Ho, /Er,/Tm, /Yb,/Lu,/Th;.
/Ta:./Ba: /Hf,, /W:. / Nb:. /.Zr: /.Al /.Si
1) The maximum degree of element's concentrating as much as 104 times or more is found only on the basis of source geochemically adequate to ore composition and is typical for low-abundant heterophyles (Hg, Au, Sb, Bi, Te and others, see the table).
2) For most cases the form of elements' concentration is controlled according to their litho-, chalco-, and siderophyle moduli and by the redox potential of minerogenic system. The role of element concentrating mineral forms in hydrothermal systems increases as both oxiphyle moduls and abundance of element decrease. Rise of isomorphic content of rare element in ores can be related to increase of their oxiphyle and lithophyle moduli.
3) In endogenic ore deposits the sequence of precipitation and geochemical zonation of non-volatile elements tend to be similar to the typical rows shown in the table or become complicated conforming to the law of masses. Thus in hydrothermal process under femic conditions the prevailing zink precipitates earlier and at greater depth then lead, while increase of sialic component of the system reverses this order.
The fundamental factor of concentrating non-volatile elements that forms the basis of the geochemical classification is the element's behaviour is dominated by their quantitive relationships of natural systems. The approach allows to elucidate their evolution better then any discrete physico-chemical parameters.
Shcherbakov, Yu.G., Origin and distribution of the elements, 689-695 (1979).
Shcherbakov ,Yu.G., Miner. Magazine 58A, 821-822 (1994).
Shcherbakov, Yu.G., Russian Geology and Geophysics 2, 69-78 (1995) Geologia i Geofizika, 80-91 (russian).