地质与勘探2025，Vol.61Issue(3)：487-498,12.DOI:10.12134/j.dzykt.2025.03.005
成都平原全新世砾石层地球化学特征及其物源区构造环境判别
Geochemical Characteristics of Holocene Gravel Layers in the Chengdu Plain and Discrimination of Tectonic Setting of Provenance
摘要
Abstract
To investigate the primary provenance areas and tectonic setting of the Holocene deposits in the Chengdu Plain,this study focused on the gravels of the Ziyang Formation in the Chengdu Plain.By collecting profile samples from drillholes(D1,D2,D3,D4),the geochemical characteristics(major elements,trace elements,and rare earth elements),grain size,and mineral composition were analyzed.The results reveal that:(1)The characteristics of major elements indicate iron enrichment in the study area.(2)Poor sorting and high hydrodynamic conditions of the Holocene sediments suggest that the sediments were originated from distant source areas.(3)The sediments were rich in minerals such as muscovite,phlogopite,polylithionite,and ferropargasite,indicating their derivation from the weathering and transport of magmatic rocks.(4)The gravels were mainly originated from slightly to moderately weathered source areas(50.69<CIA<86.10).(5)The Ni-TiO2 diagram,La/Sc-Co/Th diagram,and Al2O3-TiO2 discriminant diagram suggest diverse source areas,dominated by granodiorite and granite,with some felsic volcanic rocks.(6)The TFe2O3+MgO-TiO2 diagram,La-Th-Sc diagram,and previous studies indicate that the provenance was primarily associated with a continental island arc tectonic setting.Integrating previous research on the composition of Holocene gravels in the southwestern margin of the Sichuan Basin,this study concludes that the Longmenshan tectonic belt was the main provenance area for the Chengdu Plain during the deposition of the Ziyang Formation.关键词
全新世/物源区/构造环境/地球化学/砾石/资阳组/成都平原Key words
Holocene/provenance/tectonic setting/geochemistry/gravel/Ziyang Formation/Chengdu Plain分类
天文与地球科学引用本文复制引用
李涵,施泽明,廖容,赵丛,黄曦辉..成都平原全新世砾石层地球化学特征及其物源区构造环境判别[J].地质与勘探,2025,61(3):487-498,12.基金项目
中国地质调查局成都多要素城市地质调查项目(编号:WKZB1811SCM910328)和成都市典型地区地下空间综合评价1∶5万土地质量调查化探子题(编号:DD20189210-04)联合资助. （编号:WKZB1811SCM910328）
