典型矿集区深部地球物理探测技术示范报告数据（2021）

以甲玛-驱龙矿集区为例的典型矿集区，依据实际地质问题，构建了一套适合于3千米以浅的深部找矿的主被动源电磁/地震学联合探测技术体系。主被动源电磁学探测结果得到了钻孔岩芯物性、3千米科钻测井及巷道激电等手段资料验证。此外，在甲玛矿集区则古浪岩体前期验证的基础上，初步标定莫古朗目标靶区1处和隐伏矿体区1处。利用被动源电磁学探测与短周期密集台阵噪音面波层析成像共同揭示甲玛-驱龙矿集区间存在一个超过甲玛矿集区地球物理异常规模的高阻高速异常体（暂定义为为牧场岩体）。结合上游项目成果，以及甲玛、驱龙矿集区与岩石地球物理模型，具备斑岩型成矿的特点。驱龙与甲玛及之间在深部5km以下发现的多个高导体，它为上部岩体提供了成矿物质来源。因此，甲玛-驱龙矿集区具备一个大型资源基地潜力条件。由被动源地震学观测获得的浅部、地壳尺度S波速度结构以及接收函数综合分析，甲玛、牧场和驱龙三个大型岩体具有共同的深部成矿背景条件。即以北纬29.5°为界，南部地壳结构复杂，莫霍倾角较大，双莫霍现象明显；北部地壳内部结构简单，莫霍较为平坦。南部由于受到碰撞作用强烈，壳内结构变化明显。在北部区域莫霍下方有明显一个界面。结合已有的资料综合推测甲玛-驱龙矿集区位于印度岩石圈地幔与其地壳差异解耦的关键部位。

Taking the Jiama-Qulong ore concentration district as a typical case study, a joint active- and passive-source electromagnetic/seismic detection technology system suitable for deep ore prospecting within 3 km depth has been established based on practical geological issues. The results of active- and passive-source electromagnetic detection have been verified by data from drill core physical property measurements, 3-km scientific drilling logging, tunnel induced polarization (IP) surveys, and other methods. Additionally, based on the prior validation of the Zegulang rock mass in the Jiama ore concentration district, one Mogulang target area and one concealed ore body area have been preliminarily delineated. Using passive-source electromagnetic detection and short-period dense array noise surface wave tomography, it is revealed that there exists a high-resistivity and high-velocity anomalous body (temporarily defined as the Muchang rock mass) in the Jiama-Qulong ore concentration district, whose scale exceeds the geophysical anomaly size of the Jiama ore concentration district. Combined with the results of upstream projects and the petrophysical models of the Jiama and Qulong ore concentration districts, the area exhibits characteristics of porphyry-type mineralization. Multiple high-conductivity bodies discovered below 5 km depth in Qulong, Jiama and their interjacent areas provide metallogenic material sources for the upper rock masses. Therefore, the Jiama-Qulong ore concentration district has the potential to become a large-scale resource base. Based on the shallow and crustal-scale S-wave velocity structures obtained from passive-source seismic observations and comprehensive receiver function analysis, the three large rock masses of Jiama, Muchang and Qulong share the same deep metallogenic background conditions. Specifically, bounded by 29.5°N, the southern crust has a complex structure with a steep Moho dip and obvious double Moho discontinuities; the northern crust has a simple internal structure with a relatively flat Moho. The southern part is subjected to intense collision, resulting in significant intra-crustal structural variations. A distinct interface exists below the Moho in the northern region. Combining existing data, it is comprehensively inferred that the Jiama-Qulong ore concentration district is located at the key position of differential decoupling between the Indian lithospheric mantle and its crust.