Integrated geological and geophysical investigations for the discovery of deeply buried gold–polymetallic deposits in China

Abstract

Xiaoshan gold–polymetallic concentrated area is located in Henan Province, central China. The area is principally underlain by typical metamorphic core complexes (MCCs), along with essential components of the basins and ranges of western Henan. Mineralization occurs in the regions where the geochemical anomalies of Au and related elements are widely distributed and consist predominantly of mineralized altered rocks and auriferous quartz veins, both of which are hosted within shear zones or fractures of varying sizes and orientations. Several small‐ to medium‐sized gold–polymetallic ore deposits, along with numerous clustered occurrences, have been found in the area in recent years. However, despite the fact that the Xiaoshan District has traditionally been deemed as an excellent geological endowment area with enormous potential for large‐sized deposits, no significant discoveries have been made to date. It is suggested that the main reason responsible for the present exploration situation could be the scarcity of applications of deep‐penetration geophysical prospecting in the area. It is anticipated that integrating geological and geophysical data would be crucial to enhance the successful mineral explorations. In this contribution, a conceptual geological model for the study area was initially reviewed so that the corresponding electromagnetic responses could then be modelled, which would simulate a geophysical type of survey, with appropriate uncertainties added into the analyses. Then, based on such an integrated approach, the required precision of detecting deep‐buried deposits could then be evaluated. In addition, by employing supplementary geophysical data acquired over known deposits, it is possible to gain more instructive insights into the practical geological model. The viabilities of this approach were demonstrated through a case study in which a hidden gold deposit in the studied area was successfully detected. Geophysical surveys were carried out by employing a grounded‐wire short‐offset TEM (SOTEM) technique and revealed two new anomalies (one of which was subsequently tested by drilling). The drilling then confirmed that this anomaly was caused by an ore body 30 m in thickness occurring at about 550 m below surface.

Accretionary tectonics, deep structures and metallogeny of southern Altaids

“…Despite the fact that the Xiaoshan District has traditionally been deemed as an excellent geological endowment area with enormous potential for large‐sized deposits, no significant discoveries have been made to date. G. Xue et al (, this issue) undertake an in‐depth review on a conceptual geological model that integrates geological and geophysical data in Xiaoshan gold–polymetallic district, and efficiently model the corresponding electromagnetic responses by employing a grounded‐wire short‐offset TEM technique. The employment of this technique is crucial to enhance the successful mineral explorations and is confirmed by an ore body 30 m in thickness occurring at about 550 m below the surface.…”

Summary of technology for a comprehensive geophysical exploration of gold mine in North China Craton

“…) and energy resources (oil, petrol and coal) (Zhai et al, 2002;Sun et al, 2013;Zeng et al, 2021). Research regarding the destruction of the North China Craton (Du et al, 2008;Zhu et al, 2015;Xue et al, 2020) sheds light on its continental tectonics and is of assistance in locating mineral and energy resources (Sun, 2015).…”

Application of the AMT Method to Gold Deposits: A Case Study in the Qinling Metallogenic Belt of North China Craton

“…In the past decades years, geophysical exploration technology has made significant progress in China [8][9][10][11][12][13]. The resolution and inversion interpretation capabilities of middeep mineral exploration have greatly improved especially, providing technical support for the fine detection of metal ore in second depth space (500-2000 m) [14].…”