湖北省三峡库区秭巴公路聚集坊大桥桥头崩塌危岩体成因及防治浅析

聚集坊崩塌危岩体的治理工程已纳入《三峡库区地质灾害防治总体规划》的近期勘查、治理项目。本通过该项目的可行性研究与设计，浅析崩塌危岩体的成因及防治。     

REE geochemical characteristics and depositional environment of the black shale-hosted Baiguoyuan Ag-V deposit in Xingshan,Hubei Province,China

By means of techniques such as inductively coupled plasma-mass spectrometry (ICP-MS) and X-ray fluorescence spectrometry (XRF),REE geochemical characteristics and depositional environment of the black shales in Baiguoyuan Ag-V deposit,Xingshan,Hubei Province,were studied in this work. The black shales in a typical TC5 profile of Doushantuo Formation of upper Sinian period were obviously enriched in REE,especially in LREE. The REE patterns of the investigated samples normalized by Post Archean Australian Shale (PAAS) showed a flat or slight rightward inclination. The characteristic elements,their ratio and correlation diagrams showed that it should be hot-water deposit and the black shale in the study area was of a sedimentary origin. Redox sensitive metal elements pattern,trace elements index measurement in anoxic environment,Ce anomaly and δEu negative anomaly showed that the deposit environment of the black shales was a reducing and anoxic one and a slight change of the sea level could be identified. The samples relatively focused on the superimposed area of sedimentary rock and basalt in the diagram of La/Yb-ΣREE and La/Yb-Ce/La. So there might be accession of hot-water sedimentation during the period of the formation of the black rock series,mostly in normal terrigenous sedimentation with the participation of deep hot-water deposit.