Multi-disciplinary ore deposit exploration in Sonqor, northwest Iran

Multi-disciplinary exploration methods are used to explore for possible ore deposits in the Sonqor area, Iran, which lies within the Sanandaj-Sirjan Zone, and contains significant iron, copper and gold mineralisation. Hydrothermal alteration was mapped using field, remotely sensed, geophysical and geochemical data as well as Landsat-8 Operational Land Imager, Landsat Enhanced Thematic Mapper plus, and two Advanced Space Borne Thermal Emission and Reflection Radiometer images. Image processing techniques, viz band ratio, principal component analysis (PCA), and various spectral analysis methods were applied to map the distribution of hydrothermally altered rocks (geochemical halos) associated with porphyry (e.g. Cu–Au) mineralisation. The geochemical halos enabled vectoring to mineralised zones with mapping of advance argillic, argillic, carbonates, Fe-oxides, phyllic, propylitic and silicification using minerals such as alunite (K/Na), muscovite, kaolinite, illite, chlorite, goethite, hematite, jarosite, calcite and silica/quartz. The band ratio combination of sensors for mapping altered areas show promising results, similar to other more advanced methods. PCA exposed variations in the spatial distribution of more hydroxyl-based minerals like alunite/jarosite, whereas the geophysical magnetic survey identified the main lineaments, possible faults and magmatic intrusion boundaries. While geochemical methods show the potential occurrence of elements like Fe, Au and Fe-bearing Ti in the southeast and southern parts, and skarn-type anomalies in the northern part of Sonqor, leaking of specific geochemical elements (such as Fe, Au and Fe-bearing Ti) produce false anomalies. Copper, Pb and Zn anomalies in the central part show the possibility of sulfide-based mineralisation.KEY POINTSSpace-based satellite technologies were used to identify mineral prospects in the Sonqor area, within the iron, copper and gold-rich Sanandaj-Sirjan Zone, Iran.The Sonqor area, part of the Zagros Orogen, is within the extensive Alpine–Himalayan orogenic belt formed by collision of the Arabian continent with the Iranian microcontinent in the Late Cretaceous to Cenozoic.The western part of the Sonqor area has first rank Hg, Au, Ag, Ta and Sb anomalies with abundant detachment faults. Dacite domes with surrounding alteration have potential for Au epithermal mineralisation (Dashkasan type); the central part may yield Cu, Zn and Pb sulfide mineralisation.The Sonqor geological map suggests good potential for Au, Fe and Fe–Ti mineralisation at the contact between limestones in the eastern and southeastern parts, but greenschist and amphibolite facies metamorphism necessitates caution in interpretation of geochemical anomalies. Space-based satellite technologies were used to identify mineral prospects in the Sonqor area, within the iron, copper and gold-rich Sanandaj-Sirjan Zone, Iran. The Sonqor area, part of the Zagros Orogen, is within the extensive Alpine–Himalayan orogenic belt formed by collision of the Arabian continent with the Iranian microcontinent in the Late Cretaceous to Cenozoic. The western part of the Sonqor area has first rank Hg, Au, Ag, Ta and Sb anomalies with abundant detachment faults. Dacite domes with surrounding alteration have potential for Au epithermal mineralisation (Dashkasan type); the central part may yield Cu, Zn and Pb sulfide mineralisation. The Sonqor geological map suggests good potential for Au, Fe and Fe–Ti mineralisation at the contact between limestones in the eastern and southeastern parts, but greenschist and amphibolite facies metamorphism necessitates caution in interpretation of geochemical anomalies.

本研究采用多学科勘查方法，对伊朗桑贾尔-西尔詹带（Sanandaj-Sirjan Zone）内的松戈尔（Sonqor）地区开展潜在矿床勘查，该区域赋存规模可观的铁、铜及金矿产化。研究依托野外调查、遥感、地球物理与地球化学数据，结合Landsat-8陆地成像仪（Operational Land Imager）、Landsat增强型专题制图仪Plus（Enhanced Thematic Mapper plus）以及2幅先进星载热发射和反射辐射计（Advanced Space Borne Thermal Emission and Reflection Radiometer）影像，完成热液蚀变填图。采用波段比值法、主成分分析（PCA）及多种光谱分析技术，对与斑岩型（如铜金型）矿化相关的热液蚀变岩石（地球化学晕）分布进行填图。通过识别明矾石（K/Na）、白云母、高岭石、伊利石、绿泥石、针铁矿、赤铁矿、黄钾铁矾、方解石及石英/二氧化硅等指示矿物，完成高级泥化、泥化、碳酸盐化、氧化铁化、绢英岩化、青磐岩化及硅化等蚀变带填图，借此借助地球化学晕可定向追踪矿化区段。多传感器波段比值组合法在蚀变区填图中展现出良好效果，可与其他更先进的技术相媲美。主成分分析可揭示以羟基为主要官能团的矿物（如明矾石/黄钾铁矾）的空间分布差异，而地球物理磁法测量则可识别区域主要线性构造、潜在断裂及岩浆侵入体边界。地球化学测量结果显示，松戈尔地区东南部及南部存在铁、金及含铁钛等元素的潜在矿化线索，北部则发育矽卡岩型异常，但特定地球化学元素（如铁、金及含铁钛）的淋滤迁移会引发假异常。中部地区的铜、铅、锌异常则指示存在硫化物型矿化的可能性。

核心要点：
依托天基卫星技术，在伊朗富铁、铜、金的桑贾尔-西尔詹带内的松戈尔地区开展矿产远景调查。松戈尔地区隶属于扎格罗斯造山带（Zagros Orogen），地处由阿拉伯大陆与伊朗微大陆在晚白垩世至新生代碰撞形成的广袤阿尔卑斯-喜马拉雅造山带内。松戈尔地区西部发育顶级汞、金、银、钽及锑异常，且伴随大量拆离断层。周边发育蚀变的英安岩穹窿具备形成浅成低温热液型金矿床（达什卡桑型）的潜力；中部地区则可能产出铜、锌、铅硫化物型矿化。松戈尔地区地质图显示，东部及东南部的石灰岩接触带具备良好的金、铁及铁钛矿化潜力，但该区域发育绿片岩相及角闪岩相变质作用，因此在解释地球化学异常时需格外谨慎。
依托天基卫星技术，在伊朗富铁、铜、金的桑贾尔-西尔詹带内的松戈尔地区开展矿产远景调查。松戈尔地区隶属于扎格罗斯造山带（Zagros Orogen），地处由阿拉伯大陆与伊朗微大陆在晚白垩世至新生代碰撞形成的广袤阿尔卑斯-喜马拉雅造山带内。松戈尔地区西部发育顶级汞、金、银、钽及锑异常，且伴随大量拆离断层。周边发育蚀变的英安岩穹窿具备形成浅成低温热液型金矿床（达什卡桑型）的潜力；中部地区则可能产出铜、锌、铅硫化物型矿化。松戈尔地区地质图显示，东部及东南部的石灰岩接触带具备良好的金、铁及铁钛矿化潜力，但该区域发育绿片岩相及角闪岩相变质作用，因此在解释地球化学异常时需格外谨慎。