巨晶普通辉石的M1位分裂

巨晶普通辉石的Ｍ１位分裂李一良，支霞臣，李玉芝，李铁，张裕恒（中国科学技术大学，合肥２３００２６）关键词巨晶辉石，Ｍ１位分裂，面积约束法，近邻边效应，Ｔ位铁单斜辉石的穆斯堡尔谱学研究历时已久。但由于其晶体结构和成份的复杂性、化学不均一性及出溶现象等［...     

Stratigraphy of the upper cretaceous and lower tertiary strata in the Tethyan Himalayas of Tibet (Tingri area,China)

The 1500-m-thick marine strata of the Tethys Himalaya of the Zhepure Mountain (Tingri, Tibet) comprise the Upper Albian to Eocene and represent the sedimentary development of the passive northern continental margin of the Indian plate. Investigations of foraminifera have led to a detailed biozonation which is compared with the west Tethyan record. Five stratigraphic units can be distinguished: The Gamba group (Upper Albian - Lower Santonian) represents the development from a basin and slope to an outer-shelf environment. In the following Zhepure Shanbei formation (Lower Santonian - Middle Maastrichtian), outer-shelf deposits continue. Pebbles in the top layers point to beginning redeposition on a continental slope. Intensified redeposition continues within the Zhepure Shanpo formation (Middle Maastrichtian - Lower Paleocene). The series is capped by sandstones of the Jidula formation (Danian) deposited from a seaward prograding delta plain. The overall succession of these units represents a sea-level high at the Cenomanian/Turonian boundary followed, from the Turonian to Danian, by an overall shallowing-upward megasequence. This is followed by a final transgression — regression cycle during the Paleocene and Eocene, documented in the Zhepure Shan formation (?Upper Danian - Lutetian) and by Upper Eocene continental deposits. The section represents the narrowing and closure of the Tethys as a result of the convergence between northward-drifting India and Eurasia. The plate collision started in the Lower Maastrichtian and caused rapid changes in sedimentation patterns affected by tectonic subsidence and uplift. Stronger subsidence and deposition took place from the Middle Maastrichtian to the Lower Paleocene. The final closure of remnant Tethys in the Tingri area took place in the Lutetian.     

帕米尔东北缘地区构造变形特征与盆山结构

帕米尔东北缘乌泊尔地区是正确认识帕米尔北缘盆山结构和构造变形特征非常关键的地区,本文利用连续电磁剖面(CEMP)资料和地震资料,并结合野外地质调查资料和钻井资料,对帕米尔东北缘乌泊尔地区的盆山结构和构造变形特征进行了研究。认为帕米尔东北缘及其以北地区的盆山结构表现为帕米尔造山带向北冲断和南天山向南冲断所形成的对冲结构; 帕米尔山前为基底卷入式构造,古生界—中生界沿高角度的逆冲断层推覆到新近系和第四系之上,形成山前的古生界—中生界逆冲推覆带; 北侧由受乌泊尔断裂控制的深部隐伏冲断体系和浅部的第四纪背驮盆地所构成。研究区的新生代构造变形时间开始于上新世晚期,并持续变形至今,形成了下更新统西域组（Q1x）与下伏上新统、Q2与Q1和Q3 4与Q2之间的不整合。研究区最小构造缩短量为486 km,缩短率为481％。     

从中下三叠统膏盐特征看中下扬子早印支运动

中下扬子早 中三叠世膏盐层是对早印支运动的沉积响应,本文从膏盐的成因、中下扬子膏盐层位的差异、沉积环境的变迁、膏盐的厚度变化和产状特征、沉积中心和沉降中心的分布等方面,分析早印支运动的表现形式。中下扬子早 中三叠世依次出现陆棚台地（碳酸盐岩）、潟湖—潮坪（白云岩与膏盐）和滨海（碎屑岩）,这种大规模海退,正是早印支运动表现为构造抬升的结果。抬升过程中,残留海水在炎热干燥的气候条件下蒸发形成膏盐层,而中扬子的膏盐层位比下扬子低,据此推测中扬子先于下扬子与华北板块碰撞而抬升。平面上,现今构造格局（主要由中印支—早燕山运动形成复向斜、复背斜和推覆构造）的坳陷区主要为白云岩与（硬）石膏互层或石膏夹少量白云岩或云质石膏,膏盐层厚度大,现今构造的隆坳过渡区主要为石膏假晶、含膏云岩、石膏质白云岩、白云岩夹石膏等,膏盐层厚度小,而膏盐的厚度和产状与沉积时的水深和地势直接相关; 另外,地层等厚图显示膏盐层主要分布于当时的沉降中心。这些沉积特征显示膏盐沉积时的地势与现今隆坳相间的构造地貌存在一定程度的吻合,说明膏盐沉积时的地层已经发生了轻微的褶皱变形（未见角度不整合和地层缺失）。     

剪切波速判别地震液化势的适用性研究

本文阐述了剪切波速判别地震液化势的可行性, 对目前国内外各种剪切波速判别地震液化势的方法进行了分析对比, 指出公式(6)是一实用、可靠的判别方法。     

湘南地区稀土矿产资源开发经济意义探讨

湘南地区风化壳型稀土资源丰富，对其开发的采、选工艺和流程简单，投入资金较少，产出颇丰、经济、社会效益明显，是湘南盆困山区脱贫致富的重要途径。本文就开发湘南稀土矿的成本、效益等进行了初步测算，可供参考。     

全国地质灾害趋势预测及预测图编制

区域地质灾害预测是地质灾害研究的难题。本文运用基于地理信息系统的风险评价方法对这一问题进行了探讨。将全国剖分为2700个单元,对地质灾害进行现状评价,并与已数字化的地质灾害图件进行单要素叠加,编制了全国地质现状等值线图,在现状评价基础上,对地质灾害进行趋势预测,将降雨条件、区域地震活动、区域地壳稳定程度、区域岩组条件和人类工程活动等作为区域地质灾害演变的因素,运用模糊综合评判模型进行综合评判,编制了1:600万中国地质灾害趋势预测图。     

北极巴罗Elson湖过去450年气候与环境变化记录

北极阿拉斯加巴罗地区Ｅｌｓｏｎ湖长６０ｃｍＡＢ—６７钻孔岩芯提供了过去４５０年连续的高分辨环境变化记录。综合分析２１０Ｐｂ测年、沉积物粒度、有机质、化学元素和微体古生物化石等资料，一致反映出巴罗地区过去４５０年的气候、环境变化过程存在如下３个阶段：１）大约１５４０～１７４０年，为低海面寒冷时期；２）１７４０～１８２７年，为气候转暖－海侵过渡时期；３）１８２７年至今，为继续海侵－气候波动变暖时期。其中１８００年前后和１９４０年前后，气温较高。１９２１～１９９３年巴罗的气温记录说明，北极地区气温不仅有明显的１０ａ和６０ａ周期变化，而且年平均温度变幅极大，达４．５℃。显示极地气候变化特别强烈并不反映大幅度升温。近２０年来的变暖趋势是１８２７年以来自然的气候波动变暖的继续。     

云南东川铜矿田白锡腊铜矿床岩浆岩岩石地球化学特征

根据化学组成、稀土元素、微量元素等特征对白锡腊矿区岩浆岩进行了系统研究。结果表明：该区岩浆岩是由来自深部的碱性－超碱性玄武岩浆分异结晶而成，晚期向富碱、富硅演化，形成了与富铜矿化关系密切的基性脉岩。     

A Study on Organic Inclusions in Clastic Reservoir Rocks and Their Application to the Assessment of Oil and Gas Accumulations

Terrigenous clastic reservoir rocks are widespread in China,and nearly all the industrial oil and gas accumulations in eastern China occur in the clastic rocks.The study shows that organic inclusions are mostly distributed in the secondary fissures and pores which were ormed in the process of oil-rock interaction,rather than in the cements or secondary enlargements. The organic inclusions are dominantly organic gas-rich or are composed of pure hydrocarbons.Homogenization temperatures range mainly from 120℃ to 130℃，which shows a relatively high maturity of organic matter.Vertical and horizontal temperature changes provide the grounds for the investigation of basin evolution and thermal fluid-kinetics-model.Fluorescence spectral characteristics o the organic inclusions indicate that oils and gases in the area studied probably have experienced two-stage or two-time migration.Micro-fluorescence rescearch is one of the effective approaches to oil/source correlation and oil migration-stage determination.The abundance and occurrence of organic inclusions is one of the indicators of oil and gas abundance and accumulation in rock layers.With the help of other informatio,organic inclusions can provide the basis for the prospective assessment of oil and gas in clastic reservoir rocks.