Abstract:The problem of stratabound deposits has aroused heated controversy over the past decade of years. Some tentative ideas concerning the ore-forming mechanism of this sort of deposits are put forward in this paper on the basis of statistics of mercury and lead-zinc deposits in Guizhou Province, sedimentary facies of carbonate rocks, isotopes, inclusions and ore-forming experimental data. Mercury deposits in Guizhou are distributed mainly in Cambrianl Sinian and Triassic strata. An examination of the sedimentary facies of carbonate rocks indicates that those deposits occur unexceptionally in marginal facies of platform and depressions of tidal flat whereas lead-zinc deposits are found mostly inside the reef limestone facies at the subaqueous uplifts of the platform and are governed by the sedimentary microfacies. Ore substances were absorbed by clay, organic materials, carbonate rocks and deposited under the action of living things. Sulfur was derived chiefly from sea water; fluid inclusions contain large quantities of chlorine and some organic inclusions. Based on these facts, the presumption is made that mercury, lead and zinc were transported mainly in the form of chlorides, hydrosulfides, organic complexes, etc, belonging to eothermal brine ore-forming process of deep circulation. The deposits, therefore, bear the characteristics of sedimentary-transformation. Three stages for ore-forming mechanism could be recognized: (1) metallic substances first came from island arc volcanic formation, (2) during the middle and late phases of the greatest marine transgression, sea water evaporated and condensed, temgenous mercury was brought to the marginal facies of platform and tidal flat while lead and zinc to the reef facies to precipitate; (3) during the tectonic event, underground hot brine circulated at depth and, then deposited ore materials in weakly structural activily zones. The Wanshan mercury deposit is dominated by the following factors: (l) position-ore-bearing strata; (2) facies-microfacies of sedimentation; (3) structure-deep-seated fractures combined with faults transecting folds; (4) multiple ore-occurring levels-ore-bodies are mostly in en echelon arrangement overlapping each other.
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傅良佐.1984.贵州汞、铅-锌层控矿床成矿机制的初步探讨[J].矿床地质,3(1):83~92.1984.A Preliminary Investigation Into The Ore-Forming Mechanism Of Mercury And Lead-Zinc Strata-Bound Deposits In Guizhou Province[J].Mineral Deposits3(1):83~92
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