辽东地区硫铁矿床中电气石岩热水沉积剖面结构序列

Occurring Order of Tourmaline Rocks Associated with Pyrite Deposits in East Liaoning: An Indicator of Hot Water Deposition at Sea Bottom

电气石岩在辽东元古宙裂谷内的硫铁矿床中广泛发育，辽河群高家峪含矿建造中，富电气石岩主要与硫铁矿体成矿关系密切。这种富电气石岩产出层位稳定，在成因上具有特殊的纹层状、条带状、块状剖面结构序列。这种由纹层状电气石岩逐渐过渡到块状电气石磁黄铁矿石（层）的演变特征，是海底喷流成矿作用的典型代表。经对比研究，辽东地区的电气石岩与世界许多超大型块状硫化物矿床，尤其是沉积岩中的（ＳＥＤＥＸ）矿床中的电气石岩特征十分相似。本文通过电气石岩韵律层的自组织成因，电气石的ＦｅＯ／（ＭｇＯ＋ＦｅＯ）比值、氢氧同位素、稀土元素组成等的研究，建立了热水沉积电气石岩的序列找矿模式。提出了电气石岩是元古代克拉通裂谷环境中海底喷流作用形成的。纹层状电气石岩与块状电气石磁黄铁矿石（层）的这种成因联系具有重要找矿标志意义。它的出现可以指示热液通道，喷口的位置及热水沉积盆地的范围。从而为确立矿体的分布规律提供信息。依据这一成矿标志。

Tourmaline rocks widely occur within the pyrite deposits of the Proterozoic rift in the eastern part of Liaoning province, particularly in the pyritized sequences of the Gaojiayu formation of the Liaohe group. Genetically closely linked with pyrite mineralization, they not only rest on specialized stratigraphic levels, but also constitute a characteristic spatial order of occurrence from laminar tourmaline to banded tourmaline to massive tourmaline, an orderly orientation typical of minerlization through sea floor spouting. Comparative studies reveal that the tourmaline rocks in the eastern Liaoning have almost the same occurring features as do those associated with some superlarge pyrite deposits, mostly of sedimentary genesis, in the other parts of the world. Following systematic researches on the eastern Liaoning’s tourmaline rocks in terms of self structuring in rhythmic layers, ratios of FeO/(MgO+FeO), oxygen and hydrogen isotopes and REE pattern, a model for their hot water depositional orders was proposed for locoting the related pyrite deposits. And it was pointed out that all these tourmaline rocks should be attributed to sea floor, hot water spouting in intracraton basins. They, particularly laminar tourmaline rock tend to coexist with pyrrhotite layers, thereby serving as an important guide to hunting ores. Moreover, their occurring orders can underline what channels the hydrothermal solution flowed through, where the spouting vents were situated and how much the range of the depositional basins cover, thus providing a great deal of information about how to identify the locations of pyrite orebodies. In fact, the application of these practices to those mines which will soon be mined out has led to discovery of new orebodies in their peripheral areas.