Mesozoic intrusive magamtism-related metallogenetic system in Beichagoumen area

TIMS U-Pb ages are presented for the distinctive Mesozoic hypabyssal intrusions occurred in Beichagoumen area in northern region of Hebei province, and the metallogenetic significances of these intrusive rocks are also discussed here. These Mesozoic hypabyssal intrusions consist of dioritic porphyrite, monzonitic porphyry, amphibole biotite monzonite and granodiorite porphyry, and the latter three intrusive rocks among which yield TIMS U-Pb ages of 147.6 ± 1.6 Ma, 146.2 ±1.4 Ma and 146.2 ± 3.9 Ma, respectively, representing the forming ages of them. The formation of Beichagoumen gold, silver-bearing polymetal ore deposit is closely related to the development of these hypabyssal intrusions in time, space and genesis, which comprises the typical metallogenetic system of Mesozoic hypabyssal intrusive magmatism in northern margin of North China platform. (authors)