[1]翟文建,郭君功,杨俊峰.2018.北秦岭双龙-夏馆地区大面积榴闪岩的发现及锆石U-Pb年代学研究.大地构造与成矿学,优先出版:001-17.doi:10.16539/j.ddgzyckx.2019.04.017
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北秦岭双龙-夏馆地区大面积榴闪岩的发现及锆石U-Pb年代学研究
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《大地构造与成矿学》[ISSN:ISSN 1001-1552/CN:CN 44-1595/P]

卷:
期数:
2018年优先出版
页码:
001-17
栏目:
出版日期:
2020-12-30

文章信息/Info

Title:
The Discovery of Widespread Garnet Amphibolite in Shuanglong- XiaguanArea, North Qinling: Zircon U-Pb Geochronology
作者:
翟文建1 2 郭君功3 杨俊峰1 何 凯1 赵韵文4 翟文芳1 李兰兰1 王小娟1
(1.河南省地质调查院, 河南 郑州 450001; 2.河南省金属矿产成矿地质过程与资源利用重点实验室, 河南 郑州 450001; 3.河南省地质科学研究所, 河南 郑州 450001; 4.河南省地矿信息中心, 河南 郑州 450012)
Author(s):
(1. Henan Institute of Geological Survey, Zhengzhou 450001, Henan, China; 2. Henan Key Laboratory For Metallogenetie Process of Metal Mineral Resource and Resource Utilization, Zhengzhou 450001, Henan, China; 3. Henan Geological Science Research Institute, Zhengzhou 450001, Henan, China; 4. Information Center of Geology and Minerals of Henan Province, Zhengzhou 450012, Henan, China)
关键词:
北秦岭 双龙?馆地区 榴闪岩 秦岭岩群 郭庄岩组 高压?高压岩石 锆石U-Pb测年
Keywords:
North Qinling Shuanglong-Xiaguan area garnetamphibolite Qinling Complex Guozhang Formation HP-UHP rock zircon U-Pb dating
分类号:
P597
DOI:
10.16539/j.ddgzyckx.2019.04.017
文献标志码:
A
摘要:
通过详细的野外地质调查, 在北秦岭双龙?馆地区精确圈定出大面积榴闪岩, 榴闪岩常以似层状、条带状、豆荚状和透镜状产于秦岭岩群郭庄岩组一套混合片麻岩内, 空间上可划分三个带: 南带与松树沟一带的麻粒岩构成一个较宽的高压?高压变质带, 北带则与官坡?槐树一带的榴辉岩构成一线, 而中带向西可能延伸至丹凤大寺沟一带。区内榴闪岩主体受秦岭岩群郭庄岩组的展布形态控制, 呈面状遍布于整个郭庄岩组内, 非局限于某一侧或两侧, 暗示秦岭岩群可能整体卷入早古生代的俯冲和碰撞作用。野外宏观特征、岩相学及锆石U-Pb年代学研究表明榴闪岩原岩为辉长岩, 成岩年龄为654.1±5.6 Ma、656.1±6.7 Ma, 获得峰期高压麻粒岩相变质年龄为472.9±6.0 Ma、485.0±33.0 Ma, 其后分别在455.4±9.0 Ma、416.7±1.9 Ma和401.1±6.2 Ma遭受了多期次退变作用的叠加; 结合区域研究成果, 初步认为北秦岭高压?高压基性岩石的原岩至少存在于新元古代中期和晚期, 其成岩时代分别与扬子地块北缘新元古代中、晚期的镁铁?镁铁质岩床群一致, 并具有相似的地球化学特征, 意味着两者是否为统一大地构造背景下的同期侵位的产物, 尚待进一步研究。
Abstract:
Based on the detailed field geological survey, widespread garnet amphibolite, which is mainly distributed in the melanosome of migmatitic gneiss in Guozhuang Formation of Qinling Complex with the stratoid, podiform and lentoid shapes, was precisely identified in the Shuanglong-Xiaguan Area of Northern Qinling Mountain, and can be divided into three SE-NW trending belts: The southern belt is located in the north of Shangxian-Danfeng fault belt and lies on the southern margin of Qinling Complex. The garnet amphibolite in this belt, together with the granulite in the Songshugou Area, constitute a broad high pressure-ultrahigh pressure(HP-UHP)metamorphic belt; The northern belt, located in the south of Zhuyangguan-Xiaguan fault belt and lying on the northern margin of Qinling Complex, connects with the eclogite from Guanpo-Shuanghuaishu Area to form a narrow HP-UHP metamorphic belt; The middle belt, located in the centre of Qinling Complex, together with the garnet pyroxenite from Zhaigen area and the coesite-bearing amphibolites from Dagousi Area, are considered as the third HP-UHP metamorphic belt, which may extend westwards to the north of Dagousi Area in Danfeng. The garnet amphibolite, primarily controlled by Guozhuang Formation of Qinling Complex, is distributed planarly in the whole Guozhuang Formation and is not limited to only one-side or two sides, suggesting that Qinling Complex was totally involved into the deep subduction and collision during the early Paleozoic. Their general field features, petrography and zircon U-Pb chronology collectively demonstrate that the protolith of garnet amphibolite is gabbro with the crystallization age of 654.1±5.6 Ma and 656.1±6.7 Ma, which experienced the peak metamorphism of high-pressure granulite facies at 472.9±6.0 Ma and 485.0±33.0 Ma, and subsequently was overprinted with multistage retrogressive metamorphism of amphibolite facies at 455.4±9.0 Ma, 416.7±1.9 Ma and 401.1±6.2 Ma, respectively. Combined with the results of regional study, we preliminarily suggest that the protoliths of HP-UHP basic rocks in Northern Qinling Mountain have at least two phases at mid- and late Neoproterozoic, respectively. The diagenetic age and geochemical characteristics of HP-UHP basic rocks are similar to these of the mid- to late Neoproterozoic mafic-ultramafic sill swarms in the northern margin of the Yangtze Block, suggesting that they may be of syn-emplacement products under the united geotcetonic background. However, this interpretation needs to be further investigated.

相似文献/References:

[1]孙卫东,李曙光,肖益林.北秦岭黑河丹凤群岛弧火山岩建造的发现及其构造意义.大地构造与成矿学,1995.19(3):227.
[2]翟文建.北秦岭双龙-夏馆地区大面积榴闪岩的发现及锆石U-Pb年代学研究.大地构造与成矿学,2019.43(5):1052.doi:10.16539/j.ddgzyckx.2019.04.017
 ZHAI Wenjian,GUO Jungong.Discovery and Zircon U-Pb Dating of Garnet Amphibolite in Shuanglong- Xiaguan Area, North Qinling.Geotectonica et Metallogenia,2019.优先出版:1052.doi:10.16539/j.ddgzyckx.2019.04.017

备注/Memo

备注/Memo:
收稿日期: 2018-07-03; 改回日期: 2019-03-11
项目资助: 河南1∶50000郎坪幅等三幅区域地质矿产调查项目(DD20160043-03)、中条?耳山成矿区地质矿产调查(DD20160043)、河南区域地质调查片区总结与服务产品开发项目(DD20160345-06)联合资助。
第一作者简介: 翟文建(1983–), 男, 硕士, 工程师, 主要从事区域基础地质研究。Email: zhaiwenjian@163.com
更新日期/Last Update: 2019-08-29