徐州黄龙山豹皮灰岩地球化学特征及其古环境意义

Geochemical Characteristics and its Paleoenvironment Significance of the Leopard Limestone in Huanglongshan, Xuzhou

通过对徐州黄龙山中寒武统张夏组豹皮灰岩进行岩石学和地球化学分析,探讨了寒武纪时期苏北地区的古海洋沉积环境特征。研究结果表明,黄龙山豹皮灰岩主要由方解石组成,并受白云石化作用影响。豹皮灰岩中微量元素及稀土元素变化趋势具一致性特征,表明沉积环境相对较稳定。综合地球化学判别指标,认为黄龙山豹皮灰岩形成于炎热干旱、氧化局限海相沉积环境,成矿物质来源于古海水,并受陆源碎屑的混染。

Through petrological and geochemical analysis of the leopard limestone of the middle Cambrian Zhangxia formation in Huanglongshan, Xuzhou, the characteristics of the paleo-ocean sedimentary environment in northern Jiangsu during the Cambrian were discussed. The results show that the Huanglongshan leopard limestone is mainly composed of calcite and is affected by dolomitization. The variation trend of trace and rare earth elements in the leopard limestone is consistent, indicating that the depositional environment is relatively stable. The comprehensive geochemical discriminant indicators suggest that the Huanglongshan leopard limestone was formed in a hot and arid oxidative limited marine sedimentary environment, and its source of material originates from ancient seawater,which is contaminated by terrigenous detritus.