Zircon SHRIMP U-Pb dating and geological significance from granite bodies in Tangzhangzi and Niuxinshan, eastern Hebei Province, China

The eastern Hebei Province is well known for prospective gold deposits, while unlike other famous foreign gold deposits region, not yet any significant Au deposits are discovered, the reason can be that some regional ore exploration indicators have not been recognized so far. Through recent studies, zircon SHRIMP dating from granite rocks related to gold formation in Tangzhangzi and Yuerya granites complex are conducted, the author obtain two U-Pb ages, respectively 173±2Ma for porphyry granite in Tangzhangzi and 173±2Ma for red granite in Niuxinshan, which are in accordance to the result of red granite in Yuerya(174±3Ma), belonging to early or middle Mesozoic Yanshanian. It′s estimated that they are formed during the same magmatic activity. If the gold deposits are related to this magmatic event, then all these three deposited are probably formed by mineralization differentiation from same thermal-center and then underwent multi-phase crustal tectonic movement.