变质沉积岩区岩石地层（广义）的划分与研究

变质沉积岩区岩石地层（广义）的划分与研究熊家镛，胡建军（云南地勘局区调所）１变质地层研究历史的回顾长期以来，人们对变质岩区地层的研究，由于认为变质岩石中发育的透入性面状构造总是与变质岩区内岩层间的界线平行（Ｓ；／／ＳＯ），在实际工作中则普遍将其作为原...     

根据无机地球化学组分分析女川硅质沉积岩的沉积物组分和古海洋环境

为了评价中新统恩纳河沿岸硅质沉积岩的生烃潜力，研究了青森市和秋田七个点的露头样品的主要和次要分布的分布。根据多变量统计分析，筛选出能形成好的生烃岩的三个最佳因子，即生物源物质的供应，陆源碎屑混入的影响及缺氧的底水条件。这些因子的空间分布表明，生烃岩相发育在盆地中央的深部，在１０－９百万年期间，由于发生局部上涌，古海洋条件发生了急剧的变化。     

Nd Isotopic Composition and Material Source of Pre—and Post—Sinian Sedimentary Rocks in Xiushui Area,Jiangxi Province

Reported in this paper are the Nd isotopic compositions of the pre-Sinian and Sinian-Cambrian sedimentary rocks in the Xiushui area,Jiangxi Province.Significant differences are noticed between them in their Nd isotopic dompositions.As for the pre-Sinian lightly metmorphozed sedimentary rocks,^143Nd/^144Nd=0.512000-0.512214,CNd(T)=-8.04-9.99,and TDM=18332426Ma are suggested for the Sinian-Cambrian sedimentary rocks .These differences would reflect the diversity of material source for the sedimentary rocks deposited before and after the Sinian period.Mantle material ap-pears to have been involved in the formation of the pre-Sinian sedimentary rocks while the post-Sinian sedimentary rocks are composed mainly of recycled detritus from the continental crust.     

Biogeochemical Study of Tamarix Aphylla from Lasbela Area and Its Application in Prospecting of Ore Deposits

Biogeochemical investigation of Tamarix aphylla,a plant species, of the Las-bela area has been made.This area mainly consists of ophiolites associated with sed-imentary rocks of Jurassic and Cretaceous age .Quantitative estimations of important biogenic trace elements such as Fe,Mn,Pb,Zn,Cu,Cr,Ni, and Co have been carried out .Anomalous concentrations of these elements in plant species of certain regions can be used to locate possible occurrences of ore deposits in the area.The comparative strdy also reveals appreciable variations in the composition of trace elements in plants.The possible causes of variation in the constitrents of Tamarix aphylla from different localities have been discussed in the light of bed rock nature, mo-bility of element and average abundance in the plant.     

Diagenesis of the Sedimentary Rocks Enclosing Coaly Layers in Gavatha Area,Lesvos Island,Based on Silica Polymorph‘s Transformations

A Tertiary non-marine stratigraphic sequence composed of carbonates(limestone),siliceous carbonates,coaly layers overlain by pyroclastic rocks and lavas,outcrops in the Gavatha area of northwestern Lesvos Island.Pure earbonates eonsist almost completely of calcite,the siliceous carbonate sediments of quartz,opal-CT and calcite,the shales of quartz,opal CT, K-feldspar,smecite-illite and ealcite,and the coaly layers of organic matter,quartz,opal-CT,feldspars and pyrite,Geochemical data indicate that smectite-illite,feldspars and associated elements(La,Zr,Y,Ba,Ce)are the products of alteration of volcanic rocks in a subtropical area A combination of sources in suggested for the formation of silica polymorphs:(a) biogenic or non-biogenic silica(opal-A) that was originally present in the form of diatiom frustules of in the form of inorganically prccipitated silica;(b)transformation o opall-A to opal-CT and quartz opal-C from alteration of volcanic glass of intercalated tuffites and overlying volcanics;and(c)opal-CT deposited primarily from hydrothermal solutions.     

硅岩研究的进展

回顾了国外硅岩的研究历史，概述了当今的研究现状和未来的发展趋势，并与我国同一领域的研究状况作了对比分析，提出了改变国内硅岩研究落后现状的几点建议。     

矿石,沉积岩年龄的直接测定

为了直接测定成矿作用和沉积地层的年龄，本文总结出１１个新的同位素年龄测定对象，其中包括硫化物矿石、铁矿石、脉石英和斑脱岩等。     

细粒沉积岩显微镜鉴定的重要性

七十年代以来对沉积岩的研究日益受到重视,尤其是对与石油矿产有关的砂岩和碳酸盐岩的研究有显著的进展,但对粘土岩和其他细粒沉积岩仍然缺少镜下鉴定工作。 一、定错名称的岩石实例 现将笔者用显微镜方法发现定错名称的岩石和对“鲕状页岩”一词的意见分述如下: 1.古风化壳型粘土岩:在沈阳北部的煤田基底玄武岩的顶部有一层古风化壳型高岭石粘土岩,其外貌为紫红色带有白色斑块,硬度低(2—3),Al_2O_3含量为30％左右(据勘探报     

湖北省郧西县武当山群变沉积岩组微古植物群及其地层意义

在湖北省郧西县武当山群变沉积岩组中共发现微古植物１５属３０种。在微古植物组合中以球状藻类为主并出现膜壳表面纹饰较复杂的分子如：Ｌｏｐｈｏｍｉｎｕｓｃｕｌａ,Ｌｏｐｈｏｓｐｈａｅｒｉｄｉｕｎ和Ｍｉｃｒｈｙｓｔｒｉｄｉｕｍ。以上微古植物组合特征充分显示了我国震旦系的特色。     

鄂尔多斯盆地中生代沉积岩中微量元素的分布

研究沉积岩中分散元素在地史上的演化,对于认识沉积岩的形成条件、恢复岩相古地理以及指导寻找沉积矿产具有重要的理论和实际意义。目前,该项研究课题已引起沉积岩地球化学工作者的重视,并成为主要的研究内容之一。作者基于上述目的,研究了中生代各时期沉积岩中钒、钴、镍、铜、铅、锶、钡、铬等微量元素的分布。文中所用岩样,全系选自钻井中的岩心。微量元素系光谱定量分析。     

以沉积岩为主岩的金矿床：岩浆—热水体系末端的产物

以沉积岩为主岩的金矿床或Carlin型金矿床，目前一般认为形成于地热系统的浅部，金由大气降水热液流体将其从赋存的沉积岩中提取出来。与上述观点不同，我们提出金来源于岩浆水热流体，并沉积在贱金属和贵金属区的边缘，距原始侵入体达几公里。在马来西亚东部的Bau及犹他州的Bingham，结合内华达州内3条线性排列的含金矿带的地质、年代学和成矿作用的观察结果证实了这一模式。此模式对勘探很有用，可进行检验。