Abstract Based on systematic sampling and analysis along the vertical profiles of two skarn (diopside-vesuvianite skarn and
fluorite-diopside skarn) eluvial weathering crusts on the exocontact zone of the granite in the Cuomolong tin-polymetallic ore
district with an environment of high mountain and sparse bush meadow, the authors detected the supergene activity sequence of the
elements in the skarn eluvial weathering crust of the high and cold lake area and investigated their common and specific supergene
geochemical characteristics as well as the major ore-controlling factors. CaO and F have been drastically leached out, whereas K
2O, Na2O, SiO2, P2O5, Sr and TFe are obviously accumulated. Bi, Cu and As, which are very high in parent rocks, have been
leached out in most weathering crusts. TFe has been leached out from organic-rich weathering crusts and separated out from organic-
low weathering crusts through oxidation. Al2O3, TiO2, Sn and Be are very active in the supergene zone, and Sn has been
strongly leached out. Al2O3, MgO, Zn, B and Hg have been either leached out or accumulated, assuming different supergene
behaviors. Ag and Mo, which are abundant in parent rocks, show much less activity capacity in the organiclow overlying eluvial
weathering crust than in the organic-high overlying eluvial weathering crust.
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