Giant ore deposits related to deep structure in and around the North China Block
published: Jan 1, 1998
ArtNo. ESP136000603003, Price: 19.00 €
The North China Continental Block (NCB) is the oldest craton in China. Its complex tectonic framework and geological evolution have resulted in a series of petro-tectonic assemblages with associated mineral deposits. The NCB and other blocks were sutured together along orogenic belts at different geological times. Frequent tectonic-magmatic activity along these belts provided favorable geological environments for the differentiation and concentration of ore-forming components. As a result, major mineral deposits in the NCB mainly occur along its margins. Archean rocks in the NCB are mostly metamorphosed and are covered by Phanerozoic sediments. The oldest isotopic age for Archean basement rocks is 3.8 Ga (Lin et al., 1994). Mineral deposits of Archean age are few, and only the BIF of Algoma type, such as the Anshan Fe orefield in Liaoning Province has important economic significance (Yao, 1994). Different from some other cratons in the world, Archean Ni(Cu, Au) deposits in komatite series rocks have not been found in the NCB. During the Early Proterozoic, aulacogens and rifts were developed in the interior parts and along some margins of the NCB. In these environments, Cu deposits of VMS-type and banded Pb-Zn deposits hosted by carbonate rocks were formed (Song, 1992). Giant mineral deposits include the Hongtoushan Cu-Zn deposit (2566 Ma), Kuandian boron deposit (2167 Ma), Dashiqiao magnesite deposit (> 1900 Ma) and Qinchengzi Pb-Zn deposit, all situated in the Central Liaoning Early Proterozoic Aulacogen of the NCB. About at the same time, the Hujiayu and Tongkuanyu Cu deposits (2300-1800 Ma) were formed in the Zongtiao rift valley along the southern margin of the NCB.