高校地质学报2018，Vol.24Issue(2)：233-245,13.DOI:10.16108/j.issn1006-7493.2017092
河南南召盆地上三叠统碎屑岩地球化学特征及物源示踪
Geochemistry of the Upper Triassic Clastic Rocks in the Nanzhao Basin of Henan Province and Its Implications for Provenance
摘要
Abstract
The Triassic is the critical period when the Qinling Orogenic Belt was marked by a completely collisional orogeny.With the amalgamation of the Yangtze and Qingling blocks and the North China Block along the Mianlue and Shangdan sutures,respectively,the Qinling Orogenic Belt started to form and transformed from plate tectonic systems to intracontinental orogenic systems. The active orogenies controlled the formation and evolution of the basins adjacent to the orogenic belt.Based on the geochemistry of clastic rocks, the provenance and tectonic setting of the Upper Triassic from the Nanzhao Basin were investigated in this study.Results show that the composition of provenance was mainly felsic igneous rocks of the upper crust. The source rocks experienced a moderate chemical weathering, and the corrected chemical index of alternation (CIAcorr) values indicated that the provenance was formed in warm and humid climate and in relatively active tectonic environments. Tectonic setting of the provenance in the Taishanmiao Formation was mainly continental island arc and active continental margin, while the Taizishan Formation was continental island arc and passive continental margin.According to the near-source depositional characteristics of the Nanzhao Basin and the evolutionary process of the Qinling Orogenic Belt,we suggest that the Qinling Orogenic Belt and the southern margin of the North China Block are the important provenances of the Nanzhao Basin during the Late Triassic.The provenance of the Taishanmiao Formation is mainly provided by the basement of the North Qinling Belt,and the provenance of the Taizishan Formation is probably derived from the South Qinling Belt, North Qinling Belt and the southern margin of the North China Block, with the recycling of sediments. The transition of the Upper Triassic provenance from the Nanzhao Basin is the response to the gradually enhanced thrusting of the Qinling Orogenic Belt during the Late Triassic.This has a crucial significance to reconstruct the process of mountain building and uplifting of the Qinling Orogenic Belt and the evolutionary process of basin-orogeny systems in adjacent basins.关键词
物源分析/构造背景/秦岭造山带/南召盆地/上三叠统Key words
provenance analysis/tectonic setting/Qinling Orogenic Belt/Nanzhao Basin/Upper Triassic分类
天文与地球科学引用本文复制引用
王艳鹏,杨文涛,郑德顺..河南南召盆地上三叠统碎屑岩地球化学特征及物源示踪[J].高校地质学报,2018,24(2):233-245,13.基金项目
国家自然科学基金项目(41702106) （41702106）
河南省基础与前沿技术研究计划项目(152300410211) （152300410211）
