冀东峪耳崖金矿区的闪长岩脉侵入到赋矿峪耳崖花岗岩及高于庄组地层中,花岗岩的年龄被确定为174～ 175 Ma.本次研究选择了峪耳崖金矿区中3件闪长岩脉样品进行锆石U-Pb年龄测定,样品的阴极发光图像显示锆石大部分为自形—半自形的粒状或短柱状,具有典型的岩浆振荡生长环带,锆石Th/U值几乎全部介于0.24 ～ 1.68,属岩浆结晶成因;测年结果显示,该区闪长岩脉于晚侏罗世侵位,其中沿着金矿体平行产出的黑云母石英闪长岩脉锆石U-Pb年龄为162.4 Ma±2.7 Ma,切穿金矿体的角闪闪长岩脉锆石U-Pb年龄为154.5 Ma±5.2 Ma,由此推测峪耳崖金矿床形成于154～162 Ma的晚侏罗世.
Diorite dikes of Yu'erya Gold District in eastern Hebei province intruded into Yu'erya Early Middle Jurassic gold-bearing granites,which are dated to be 174 Ma to 175 Ma,and Gaoyuzhuang formation strata.Zircon U-Pb dating are reported for 3 diorite dike samples in Yu'erya Gold District.The CL images show that the zircon is mostly euhedral-subhedral in shape and has typical magmatic oscillatory growth zoning;Almost all Th/U ratios are between 0.24 and 1.68,implying the magmatic crystallization origin of zircons.The dating results indicate that the intrusion of diorite dikes from Yu'erya Gold District took place in the Late Jurassic.The U-Pb age of zircons from the biotite quartz diorite dike parallel to gold-bearing ore bodies is 162.4 Ma ±2.7 Ma,while the U-Pb age of zircons from am phibolites diorite intersecting gold-bearing ore bodies is 154.5 Ma ± 5.2 Ma,suggesting that the gold mineralization took place in the Late Jurassic 154 Ma to 162 Ma age.
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