Relationships between Alluvial Facies/Depositional Environments, Detrital Zircon U‐Pb Geochronology, and Bulk‐Rock Geochemistry in the Cretaceous Neungju Basin (Southwest Korea)

Minerals

MinGyu Kwon¹  Hyojong Lee¹  Taejin Choi¹  Hyeongseong Cho²  Jong‐Sun Kim³  Min Huh⁴  Yul Roh⁴  Seungwon Shin⁵ 

[1] Department of Energy and Resources Engineering, Chosun University, Gwangju 61452, Korea;Department of Geology, Gyeongsang National University, Jinju 52828, Korea;Ecological Survey Division, National Park Research Institute, Korea National Park Service, Wonju 26466, Korea;Faculty of Earth Systems and Environmental Sciences, Chonnam University, Gwangju 61186, Korea;Geological Research Center, Geology Division, KIGAM, Daejeon 34132, Korea;

关键词: provenance;    compositional heterogeneity;    major element;    detrital zircon;    nonmarine basin;   

DOI  :  10.3390/min10111023

来源: DOAJ

【 摘 要 】

Zircon U-Pb geochronology and bulk-rock geochemistry analyses were carried out to investigate their relationship with depositional environments of the non-marine Neungju Basin sediments in South Korea. The Neungju Basin was formed in an active continental margin setting during the Late Cretaceous with associated volcanism. Detrital zircon age distributions of the Neungju Basin reveal that the source rocks surrounding the basin supplied sediments into the basin from all directions, making different zircon age populations according to the depositional environments. Mudstone geochemistry with support of detrital zircon U-Pb age data reveals how the heterogeneity affects the geochemical characteristics of tectonic setting and weathering intensity. The sediments in the proximal (alluvial fan to sandflat) and distal (playa lake) environments differ compositionally because sediment mixing occurred exclusively in the distal environment. The proximal deposits show a passive margin signature, reflecting their derivation from the adjacent metamorphic and granitic basement rocks. The distal deposits properly indicate an active continental margin setting due to the additional supply of reworked volcaniclastic sediments. The proximal deposits indicate a minor degree of chemical weathering corresponding to fossil and sedimentological records of the basin, whereas the distal deposits show lower weathering intensity by reworking of unaltered volcaniclastic detritus from unstable volcanic and volcaniclastic terranes. Overall, this study highlights that compositional data obtained from a specific location and depositional environments may not describe the overall characteristic of the basin.

【 授权许可】

Unknown