湖北大洪山打鼓石群沉积时限——来自碎屑锆石U-Pb年龄的证据

发布时间：2018-03-04 19:11

本文选题：大洪山　切入点：打鼓石群　出处：《地质通报》2017年05期 　论文类型：期刊论文

【摘要】：出露于扬子北缘大洪山地区的打鼓石群是扬子地区保留比较完整的中元古代地层,其上被青白口系花山群不整合覆盖。通常认为其与神农架群时代相当,但缺乏物源及同位素地质年代学证据。首次报导了打鼓石群底部太阳寺组砂岩的碎屑锆石U-Pb年龄。测年结果显示,该砂岩中碎屑锆石最古老的年龄为3.1~3.2Ga,最年轻年龄为1124Ma,并在2.65Ga和2.75Ga出现统计峰值,且年龄组成与崆岭杂岩区和杨坡杂岩区的多期岩浆活动具有较好的可比性。而鄂西地区神农架群沉积于1.1~1.4Ga,主要统计峰值年龄为1.6Ga、2~2.1Ga、2.7~2.8Ga。因此,打鼓石群沉积时间晚于神农架群,两者非同物异名。
[Abstract]:In the northern margin of the Yangtze plate in the greater Hongshan area is the Yangtze area group of stone drums to retain complete middle Proterozoic strata, which is Qingbaikouan Huashan group unconformity. It is generally believed that the Shennongjia group with considerable time, but the lack of provenance and isotopic geochronology evidence. First reported the detrital zircon U-Pb age group of stone drums the bottom of the temple of sandstone. The dating results show that, the oldest detrital zircon age of 3.1~3.2Ga in the sandstone, the young age of 1124Ma, and the statistical peak at 2.65Ga and 2.75Ga, and the age and composition of the Kongling complex area and Yang Po metamorphic complex multi period magmatic activity has good comparability Shennongjia west area of Hubei. While the group was deposited in 1.1~1.4Ga, the main statistical peak age of 1.6Ga, 2~2.1Ga, 2.7~2.8Ga. and Ta Shi Qun deposition time later than the Shennongjia group, the two non synonyms.

【作者单位】：中国地质调查局武汉地质调查中心;中国地质调查局古生物与生命-环境协同演化重点实验室;
【基金】：中国地质调查局项目《湘西-鄂西成矿带关键地区地质调查》(编号:12120113061700)、《武当-桐柏-大别成矿带关键地区地质调查》(编号:12120113067900)
【分类号】：P512.2;P597.3

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