沉积学报2024，Vol.42Issue(4)：1342-1353,12.DOI:10.14027/j.issn.1000-0550.2022.093
辽东湾海域新元古界长龙山组石英砂岩物源特征及其地质意义
Characteristics by Provenance of Quartz Sandstone from the Neoproterozoic Changlongshan Formation in the Offshore Liaodong Bay and Its Geological Significance
摘要
Abstract
[Objective]The quartz sandstone of the Changlongshan Formation in the Qingbaikou system from the Neoproterozoic was encountered during drilling in the southwestern Liaodong Bay,Bohai Sea.The in-depth study of its provenance characteristics is of great significance to the anatomy of major geological events from the Archean to Proterozoic in the North China Craton.[Methods]Five quartz sandstone samples collected from around 2482 meters in well BD4-1a were analyzed for whole-rock geochemistry and detrital zircon U-Pb geochronology.[Results]The quartz sandstones had high SiO2 content(88.53%-93.06%),the chemical index of alteration(CIA)value was 69.5～71.6,the index of compositional variability(ICV)value was 0.69-3.99,and the samples displayed high composition-al maturity,structural maturity,and moderate weathering.The Th/U ratio ranged from 3.46-4.92,the Cr/Zr ratio of 0.17～0.35.The sum of the rare earth elements(ΣREE)is(8.26-24.12)×10-6,the low/heavy rare earth element ratio(LREE/HREE)was 6.28～10.21,and the δEu was 0.77-1.04,which shows a weak negative anomaly.The U-Pb ages of detrital zircons ranged from 2744-1581 Ma;the main age peak was～1845 Ma,and the subordinate age peaks were～2225,～2340,～2600,～2725 Ma,respectively.[Conclusions]Whole-rock geochemistry indicates that the provenance mainly comes from felsic rocks of the upper crust.The 2.7-2.5 Ga detrital zircons record the growth and tectonothermal events of the continental crust in the North China Craton.The 2.2-1.8 Ga detrital zircons correspond to the crystalline basement formation during the amalgamation of the eastern and western blocks of the North China Craton,recording the geological events of the Columbia supercontinent's assembly.The 1.8-1.6 Ga detrital zircon ages likely record the breakup of the Columbia supercontinent.关键词
渤海/碎屑锆石/地球化学/物源/哥伦比亚超大陆Key words
Bohai Sea/detrital zircons/geochemistry/provenance/Columbia supercontinent分类
天文与地球科学引用本文复制引用
赵子霖,周雪威,李夔洲,郭涛,彭靖松,侯明才..辽东湾海域新元古界长龙山组石英砂岩物源特征及其地质意义[J].沉积学报,2024,42(4):1342-1353,12.基金项目
国家自然科学基金项目(42102141) （42102141）
中国博士后科学基金(2022T150076) （2022T150076）
中海石油(中国)有限公司科研项目(CCL2014TIXZSS0870) （中国）
成都理工大学油气藏地质及开发工程国家重点实验室项目(40200-02021301)[National Natural Science Foundation of China No.42102141 （40200-02021301）
China Postdoctoral Science Foundation,No.2022T150076 （）
Research Porjects of China National Offshore Oil(China)Co.,Ltd.,No.CCL2014TIXZSS0870 （China）
Project of State Key Laboratory of Reservoir Geology and Development Engineering,Chengdu University of Technology,No.40200-02021301] （）
