甘肃北山红山铁矿地质—地球物理找矿模型预测隐伏矿

红山铁矿床产于青白口系变质岩中,属低品位大型沉积—变质型磁铁矿床。此类矿床的岩矿石组合中磁铁矿石具有较强磁性,围岩几乎无磁性。矿床的航(地)磁异常一般呈条带状展布,延伸范围较大,且与铁矿层的走向基本一致。当矿体出露或埋深浅时,磁异常连续性好、梯度陡、强度高的单峰异常,并伴有一定的负值异常,当矿床埋藏深度大时,表现为强度不大的低缓异常,是磁测找隐伏矿的地质—地球物理标志。经系统研究矿区以往磁测和勘探资料,提出预测隐伏矿及其赋存的构造有利部位。

GEOLOGICAL-GEOPHYSICAL PROSPECTING MODEL OF HONGSHAN IRON DEPOSIT IN BEISHAN REGION OF GANSU PROVINCE AND PREDICTION OF BURIED DEPOSIT

Hongshan iron deposit is a low grade, large sedimentary-metamorphic magnetite deposit which occurred within metamorphic rock of Qingbaikou Series. The ore of such kind of deposit show the intensive mag- netic, but little of country rock. The aeromagnetic （magnetic） anomaly of the deposit usually has the feature of a stripped distribution with the large expansion in the same direction as the strike of ore bed. It is an obvious continuous, steep gradient and intensive anomaly single peak, which is usually accompanied with a certain negative anomaly if the deposit is outcrop or shallow-buried, but a weak and gentle anomaly while the deposit is deep burial.