宽甸北部早元古宙铅锌矿地质特征及成因讨论

GENESIS AND GEOLOGICAL CHARACTERS OF THE EARLY PROTEROZOIC CARBONATE-HOSTED Pb-Zn DEPOSITS IN THE NORTHERN KUANDIAN AREA.LIAONING PROVINCE

辽宁宽甸北部早元古宙铅锌矿位于辽东青城子—吉林荒沟山—朝鲜检德铅锌矿带上。赋存于辽东优、冒地槽的过渡带,靠近优地槽一侧的碳酸盐岩建造中。矿体受岩相、岩性控制明显,属层控矿床。吕梁构造旋回的变质变形作用对矿带的改造不明显。矿带的同位素特征表明,张家堡子铅锌矿形成于封闭盆地环境,矿质来源于大陆边缘深部液态矿源层;而高丽墓子铅锌矿带则形成于正常海洋环境,表现了明显的原始沉积矿床的特点。

Carbonates and clastic rocks are well developed in the second-order basins of anEarly Proterozoic aulacogen in the northern Kuandian area,Liaoning Province.Thecarbonates in the area consist of two parts:the upper and the lower carbonate for-mations.The clastic rocks occured between the two formations.Two Pb-Zn ore belts existin both of the upper and lower carbonate formations and are called B and A-beltrespectively.Several tens of Pb-Zn ore bodies are found in A-belt.Some Pb-Zn orebodies are apparent in vertical zoning in a sequence of Fe-Zn-Pb-Ba from lower tothe upper.Geological and geochemical research show that the ore components in theA-belt was exhalated from the liquid source bed deeply underneath the margin (?)f thecontinent and was precipitated in a closed second-order basins while those in theB-belt was derived from the upper crust and was deposited in a normal oceanic enviorn-ments for apparent and continous lamellars in the ores.The second-order basins inLiaodong-Jinan-North Korean Peninsular aulacogen at the margin of the Archean cratonare promising sites for looking For the deposits formed by exhalation of the liquidsource bed deeply underneath the continent.