Regional heterogeneous temporal–spatial distribution of gold deposits in the North China Craton: A review

Abstract

The gold mineralization of the North China Craton (NCC) is characterized by regional heterogeneous distribution. Such a feature is mainly reflected by the spatial dispersity and local concentration, as well as multiperiods of gold‐forming events. Gold deposits are principally converged in the Jiaodong, Xiaoqinling‐Xiong'er Mountain, Jidong, Liaodong, and Taihang Mountain regions. The northern margin of the NCC is strongly enriched in Au, Mo, and Cu elements, whereas its southern and eastern margins trend to show significant enrichment of Au–Mo and Au, respectively. Among them, the early period of Mesozoic mineralization is Au–Mo–Pb–Zn combination, the peak is Au, and the late period is Au–Ag combination. The Early Cretaceous is the main gold metallogenic epoch of the NCC followed by the Middle–Late Triassic and Jurassic. Generally, gold mineralization time of the Xiaoqinling‐Xiong'er Mountain and Taihang Mountain is a little earlier than those of Jiaodong gold deposits; some of Jidong (Jinchangyu, Yuerya, and Niuxinshan) and the Liaodong (Baiyun and Maoling) gold deposits were formed in the Triassic–Jurassic. Overall, the uneven distribution of gold deposits in the NCC is generally controlled by the tectonic evolution and interaction of the regional geological blocks, the hydrothermal alteration and gold activation in the metamorphic basement, and the Mesozoic magma activity. In the Middle Jurassic and before, the tectonic evolution of the NCC was mainly influenced by the Central Asian Orogenic Belt and the Qinling Orogenic Belt. Tectonic system transition from extrusion to extension, locally developed mantle upwelling and lithospheric thinning, as well as a series of Middle Triassic–Jurassic magmatic activities, and even the presence of alkaline rocks along the east–west direction occurred on the northern margin of the NCC, which generated a series of Au–Mo deposits. This is the first craton destruction and gold mineralization event that occurred in the northern margin of the NCC after its formation. In the Cretaceous and after, the geological evolution of the NCC was mainly controlled by the ancient Pacific Plate. The NCC was subjected to extensive lithospheric thinning, which in turn led to a more large‐scale gold mineralization. In addition, it is found that these ore‐forming materials sourced from the metamorphic rock are not entirely dependent on the gold content but also affected by one or more geological processes, which activate and extract gold from the wall rock and upgrade it in suitable tectonic environments. The influence of granitoids and intermediate–basic dikes in these gold deposits seems like a “hot machine,” which is the source of metallogenic hydrothermal fluid, and it is also a possible source of some ore‐forming minerals.