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Detrital zircon records of late Paleoproterozoic to early Neoproterozoic northern North China Craton drainage reorganization: Implications for supercontinent cycles
GSA Bulletin ( IF 3.9 ) Pub Date : 2020-09-01 , DOI: 10.1130/b35506.1
Chaohui Liu 1 , Guochun Zhao 2, 3 , Fulai Liu 1 , Jianrong Shi 4 , Lei Ji 1
Affiliation  

Statherian through Tonian strata of the Langshan–Zha’ertai–Bayan Obo–Huade rift zone (LZBH) at the northern margin of the North China Craton provide an excellent record of changes in sediment provenance related to the supercontinent dispersal and amalgamation. During the late Paleoproterozoic to early Neoproterozoic, the LZBH developed over the Yinshan Block and was flanked by the Khondalite Belt to the south, the Trans–North China Orogen and Yanliao rift zone to the east, ultimately preserving a >7000-m-sequence of fluvial, marginal marine, and offshore marine sediments. In order to decipher the influence of these tectonic features on sediment delivery to the area, we evaluated 4955 U-Pb and 1616 Lu-Hf analyses from 66 samples across the entire LZBH, of which 1002 U-Pb and 271 Lu-Hf analyses from 12 samples are newly reported herein. The detrital zircon results indicate three stratigraphic intervals with internally consistent age peaks: (1) Changcheng to lower Jixian system (Statherian–lower Calymmian), (2) upper Jixian system (upper Calymmian), and (3) Qingbaikou system (Tonian). Statistical analysis of the detrital zircon results reveals two distinct changes in sediment provenance. The first transition, between the lower and upper Calymmian, reflects a provenance change from the basement of the Yinshan Block and the Khondalite Belt to a mixed signature, indicating derivation from both basement and Statherian rift-related magmatic products. Such a transition implies establishment of east–west drainage systems traversing the Paleoproterozoic Trans–North China Orogen caused by continued rifting since Statherian and pre-magmatic uplift during breakup of the North China Craton from the Columbia supercontinent. The second transition is indicated by the presence of Mesoproterozoic detrital zircons with juvenile Hf isotopic features since Tonian time and the up-section and northward increase of Mesoproterozoic detrital zircons. Their provenance is interpreted to be the Fennoscandian shield by a pancontinental drainage system related to aggregation of the Rodinia supercontinent. Thus, the detrital zircon spectra in the LZBH document the transition from initial unroofing of local uplifted basement of the Yinshan Block and Khondalite Belt to the distant Yanliao rift zone, then to the more distant Fennoscandian shield.

中文翻译:

华北北部新元古代晚期至新元古代早期碎屑锆石记录:超大陆循环的意义

华北克拉通北部边缘的郎山—扎哈尔泰—巴彦奥伯—华德裂谷带(LZBH)的斯太尔期至通尼地层,提供了与超大陆扩散和合并有关的沉积物来源变化的出色记录。在古元古代晚期至新元古代早期,LZBH发育于银山地块之上,并在其南侧是高棉岩带,东侧是华北-华北造山带和延辽裂谷带,最终保留了> 7000 m的层序。河流,边缘海洋和近海海洋沉积物。为了解释这些构造特征对沉积物向该区域输送的影响,我们评估了整个LZBH中66个样品的4955 U-Pb和1616 Lu-Hf分析,其中1002 U-Pb和271 Lu-Hf分析来自本文新报告了12个样品。碎屑锆石的结果表明,三个地层间隔具有内部一致的年龄峰值:(1)长城至下蓟县系统(施塔期-下卡里蒙),(2)上蓟县系统(上卡里蒙)和(3)青柏口系统(通年)。碎屑锆石结果的统计分析揭示了沉积物来源的两个明显变化。上,下卡里米亚之间的第一个过渡反映了从阴山地块和宽达岭带的基底到混合特征的物源变化,这表明基底和史黛西裂谷相关的岩浆产品均是衍生的。这种过渡意味着东西向排水系统的建立,横贯古元古代跨华北造山带,这是由于自华南克拉通从哥伦比亚超大陆解体以来的史达特期和岩浆前隆升以来的持续裂谷引起的。第二个转变是自通尼时代以来存在具有幼年Hf同位素特征的中生代碎屑锆石,以及中生代碎屑锆石的向上和向北增加。他们的起源被与罗迪尼亚超大陆聚集有关的全大陆排水系统解释为芬诺斯堪的亚盾。因此,LZBH中的碎屑锆石光谱记录了从银山块体和宽达岭带的局部隆起基底的初始解顶到远处的延辽裂谷带的转变,
更新日期:2020-09-01
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