用正交函数拟合方法揭示新疆阿舍勒铜锌矿区构造

THE GEOLOGIC STRUCTURE IN THE ASHELE COPPER-ZINC DISTRICT, XINJIANG, AS REVEALED BY THE METHOD OF ORTHOGONAL FUNCTION FITTING

正在勘探中的新疆哈巴河县阿舍勒铜锌矿床,属海相火山喷气-沉积成因。矿体呈厚大扁豆状,具层控特征,且矿体和围岩密度差别较大。为了更好地解决矿区构造背景,探索、研究深部找矿信息与标志,本文采用数学地质-正交函数拟合方法及多次拟合技术,对具有空间形态特征的地质信息进行处理。结果将成矿层的局部重力异常从实测布伽异常值中分离出来。在分离出的局部重力异常等值线图上,显示出了三条南北向的重力高异常带、构造转折带及地表不易观察得到的北西向、东西向断裂构造。据此,成功地揭示了矿区构造成矿带的轮廓,指出了找矿方向。

The Ashele copper zinc deposit that is under exploration in Habahe County, Xinjiang, is of marine volcanic exhalation-sedimentary origin. Thick, large and lenticular orebodies exhibit the stratabound charater, and there is appreciable difference in density between orebodies and country rocks. In order to have a better understanding of the structural setting of the ore district and study and gain the information and indications of mineral prospecting at depths, the method of mathematic geology-orthogonal function fitting-and the quandratic fitting technique were used in processing the geological infromation about the morphological features in space. The local gravity anomalies due to the ore horizons were separated from the measured Bouguer anomalies according to the results of the processing. Thus three N-S-trending gravity high anomaly belts , structural turning zones and the N-W- and E-W-trending fracture structures, which are not easy to observe on the ground surface, are clearly displayed on the processed local gravity anomaly contour map. On that basis, the authors have outlined successfully a tectono-metallogenic belt, unveiled the structures in the ore district and pointed to the direction in ore prospecting.