摘要: |
奥陶纪—泥盆纪时期,受加里东构造活动的影响,北祁连洋盆经历了俯冲消亡至造山的复杂转换。其中,志留纪是记录了盆山转换的重要大地构造过渡阶段,然而北祁连造山带在该时期的盆地性质一直存在争议。本文对北祁连地区志留系沉积地层开展了详细的野外地质调查及室内测试分析,通过岩性、沉积构造和古生物化石组合等方面的研究,共识别出潮坪相、浅海陆棚相及半深海相三种沉积相类型。此外,基于前人的研究成果和本研究的新资料,编制了全新的北祁连地区志留纪沉积构造格架、沉积盆地类型及空间配置关系图。在此基础上,通过区域地层对比,以及岩相古地理编图研究,重建了北祁连造山带志留纪沉积盆地充填序列,并采用造山带岩相古地理编图方法编制了全新的研究区志留纪岩相古地理图。 |
关键词: 北祁连造山带 志留纪 造山带岩相古地理 |
DOI:10.19826/j.cnki.1009-3850.2020.07004 |
附件 |
投稿时间:2020-03-12修订日期:2020-04-27 |
基金项目:国家自然科学基金(编号:NO.41772113)资助 |
|
Sedimentary facies and palaeogeography of the Northern Qilian orogenic during the Silurian |
Mou Chuan-long, Hou Qian, Zheng Bin-song, Ge Xiangying, Zan Bo-wen |
(1. Chengdu Center, China Geological Survey, Chengdu 610081, Sichuan, China; 2. Shandong University of Science and Technology, Qingdao 266590, Shandong, China; 3. Key Laboratory of Sedimentary Basin and Oil and Gas Resources, Ministry of Natural Resource, Chengdu 610081, Sichuan, China) |
Abstract: |
During the Ordovician-Silurian, the northern Qilian orogenic belt underwent a complex transition from subduction to orogeny which influenced by Caledonian tectonic activity.Its Silurian is an important tectonic transition stage of basin-mountain conversion, but the nature and tectonic setting of its Silurian deposition has been controversial. The palaeogeographic analysis in this paper is based on the field and laboratory examination in integration with lithology, textures and structures, and fossil assemblages. Three sedimentary facies,including tidal-flat facies, shallow shelf facies and bathyal facies are discriminated.In addition, based on the previous research and the new data of this study, the new relation map of Silurian sedimentary structure framework, sedimentary basin types and spatial configuration in North Qilian area is compiled. Furthermore, sedimentary basin filling sequence and paleogeographic evolution of the study area are restored on the basis of the regional stratigraphic correlation and lithofacies paleogeographic mapping. |
Key words: Northern Qilian Orogenic Silurian sedimentary facies and palaeogeography of orogenic belts |