地质与勘探2011，Vol.47Issue(6)：982-993,12.
湖北宜昌白果园陡山沱组磷块岩地球化学特征研究
Geochemical Characteristics of Phosphorites in the Doushantuo Formation at Baiguoyuan, Yichang, Hubei Province
摘要
Abstract
Phosphatic series of Baiguoyuan in Yichang is located in the northwest of the Huangling anticline, which is a part of Yichang phosphate. The phosphorite was formed in the transgression of the Sinian Doushantuo period. The emrichment phosphorus lies in the Zhang cun-ping layer of Doushantuo Formation. From geochemical study on the profile of Baiguoyuan, we obtained the following conclusions ： （ 1 ）. The rich layer of phosphorite in Baiguoyuan is mainly composed of phosphate mineral, which is constituted by P2O5 and CaO, carbonate minerals characterized by CaO and CO2, clay minerals and silica minerals made up of A1203and SiO2. The content of A12O3and SiO2 is higher than other areas. But the content of P2O5 is lass than the average content. （2）. The enrichment of Cu, Pb, Ba, Zn, As, U and Mo in phosphorus are associated with biological activity. The content of Co and Ni is relatively low, and the content of Sr is 655×10^-6. （3）. The content of LREE is highest, and HREE is lowest, ∑REE is very low. The distribution pattern of phosphorite＇s REE in Baiguoyuan is close to the distribution pattern of biological phosphorite＇s REE. The Ce_anom of phosphorite in the Zhaug cun-ping layer is -0. 091 ,and other phosphatic layers Ce is all more than-0.1 ,which reflects a reduced sedimentary environment. This feature may be caused by closed sedimentary environment and stran- ded water, or biological activity leading to the value of Eh＇s declining in the local water. （5）. The trend of δ13C_carb in Doushantuo Formation of Baiguoyuatl could be compared to that of elsewhere around the world. It is found that the δ13C_carb bValues showed the trend of positive excursion at the early - middle stage of Doushantuo period. It related to biological recovery and sedimentary of phosphorite. The δ13C_carb value was highest at the middle stage of Doushantuo period, which shows a higher biological productivity and a higher burial rate of organic carbon. The δ13C_carb Value decreased at the late stage of Doushantuo period,关键词
震旦系/陡山沱组磷块岩成因/地球化学特征湖北宜昌Key words
Sinian Doushantuo Formation/genesis of phosphorite/geochemical characteristics/Yichang/Hubei分类
天文与地球科学引用本文复制引用
密文天,李德亮,范昱..湖北宜昌白果园陡山沱组磷块岩地球化学特征研究[J].地质与勘探,2011,47(6):982-993,12.基金项目
教育部高等学校博士点基金“寒武系牛蹄塘组热水沉积中的微生物群的研究”（编号：20095122110013）资助. （）
