沉积学报2025，Vol.43Issue(2)：467-480,14.DOI:10.14027/j.issn.1000-0550.2023.025
湘西北早寒武世热水活动对周缘沉积的影响
Effect of Early Cambrian Hydrothermal Activities on the Peripheral Deposition in Northwestern Hunan
摘要
Abstract
[Objective]The hydrothermal activities during the Early Cambrian in northwest Hunan significantly in-fluenced the sedimentary strata at that time.However,the specific influence of the hydrothermal activities on the sur-rounding area remains unclear.[Methods]Based on the analysis of total organic carbon(TOC),X-ray diffraction(XRD),major and trace elements,etc.,the differences in the sedimentary geochemistry at the bottom of lower Cam-brian Niutitang Formation in wells Huanye 1(HY1),Xiangan 1(XA1),and Xiangji 1(XJ1)in northwestern Hu-nan were compared and analyzed.[Results]Research shows that combined with the sedimentary setting and structur-al characteristics of the early Cambrian,the specific influence and extent of hydrothermal activities on the peripheral sediments were systematically revealed.These wells were far from the hydrothermal activities,and the contribution from the hydrothermal activities is small.However,certain geochemical indicators suggest that there are both normal and hydrothermal deposition characteristics at the bottom of the Niutitang Formation black shales.XJ1 was the most affected by the hydrothermal activity,XA1 was practically unaffected,and HY1 was moderately affected.Co/Zn,LaN/CeN,∑REE,and ∑ LREE/∑ HREE are indicators for showing hydrothermal activities.Ba,Mo,Ni,U and V are highly enriched in that stratum.The sedimentary environment of strong reducing or vulcanization may be the main factor for the enrichment of these elements.The abundance of organic matter within a certain range has a positive correlation with the enrichment degree of the different elements.XJ1,HY1 and XA1,which are affected by the hydrothermal activities in turn,differ in their response of sedimentary geochemistry characteristics.XJ1 in the deep-sea basin is more dependent on the supply from the deep internal source of the remote debris.[Conclusions]The hydrothermal activities provide a material basis that is rich in these elements by the contrast in different wells.Furthermore,the hydrothermal activities strengthen the reducibility of the surrounding sedimentary environment,which is conducive to the further enrichment of these elements and organic matter.This influence gradually decreases with the increase of the distance from the hydrothermal activities.However,the response of hydrothermal sediment is relatively confusing and vague owing to the complex factors on the content of elements in the black shales.关键词
湘西北地区/牛蹄塘组/热水活动/黑色岩系/元素富集/氧化还原条件Key words
northwestern Hunan/Niutitang Formation/hydrothermal activities/black shales/element enrichment/redox conditions分类
天文与地球科学引用本文复制引用
段宸章,黄俨然,罗满,高钧健..湘西北早寒武世热水活动对周缘沉积的影响[J].沉积学报,2025,43(2):467-480,14.基金项目
国家自然科学基金项目(41603046) （41603046）
湖南省自然科学基金项目(2023JJ30231)[National Natural Science Foundation of Chi-na,No.41603046 （2023JJ30231）
Natural Science Foundation of Hunan Province,No.2023JJ30231] （）
