垂直断层附近三维不均匀体点源电场的边界单元法

本文将给出垂直断层附近三维不均匀体电阻率法的数值解，所用方法是边界单元法，但基本解的选择与以往的边界单元法不同。     

土的边界面本构模型研究进展

简述了土的边界面本构模型国内外研究状况，阐述了其基本思想。对边界面模型作了简要评述，提出了边界面模型研究的发展趋向。     

Screening Effect of the Diffusive Boundary Layer in Sediments of Lake Aha in the Suburbs of Guiyang City,Guizhou Province

The redox cycle of iron and manganese is a major geochemica process at the boundary layers of lake sediments.Lake Aha,which lies in the suburbs of Guiyang City,Guizhou Province,China,is a medium-sized artificial reservoir with seasonally anoxic hypolimnion,Long-term sedimentary accumulation of iron and manganese resulted in their enrichment in the upper sediments,In the anoxic season,Fe^2 and Mn^2 ,formed by diological oxidation,would diffuse up to overlying waters from sediments.However,the concentration of oxidation,would diffuse up to overlying waters from sediments,However,the concentration of Fe^2 increased later and decreased earlier than that of Mn^2 .Generally,sulfate reduction occurred at 6 cm below the sediment-water interface.Whereas,in the anoxic season.the reduction reached upper sediments,inhibiting the release of Fe^2 ,The Fe concentration of anoxic water is quickly decreased from high to low as a result of reduction of the suplhur system.     

鄂尔多斯地区南部与东秦岭早古生代的关系和演化——以中层序(mesosequence)观点述之

鄂尔多斯地区南部和东秦岭北部是华北稳定陆块与秦岭海槽之间的过渡带．早古生代可划分为５个中层序（ｍｅｓｏｓｅｑｕｅｎｃｅ）．ＭＳ－１．包括下寒武统及中寒武统徐庄组，为混水台地沉积体系，时间跨度在３５Ｍａ；ＭＳ－２．包括下寒武统张夏组、上寒武统和下奥陶统冶里—亮甲山组，为清水台地沉积体系，时间跨度近３７．９Ｍａ；ＭＳ－３．包括下奥陶统马家沟组和峰峰组，为蒸发型台地沉积体系，时间跨度近３１Ｍａ．三者组成显生宙第一大层序（ｍｅｇａｓｅｑｕｅｎｃｅ），形成一巨大沉积旋回，为地壳动力伸张所成；ＭＳ－４．包括赵老峪组，为弧后盆地形成的斜坡沉积体系和盆地沉积体系，时间跨度１７Ｍａ；ＭＳ－５．系上奥陶统，包括背锅山组、上店组、两岔口组等，为残留海台地型沉积体系．这两个中层序形成显生宙第二大层序的主体，形成一巨大沉积旋回，为地壳动力挤压所成．     

Numerical modeling of 3-D terrain effect on MT field

Using the boundary element method, the numerical modeling problem of three-dimensional terrain effect on magnetotelluric (MT) field is solved. This modeling technique can be run on PC in the case of adopting special net division. The result of modeling test for 2-D terrain by this modeling technique is basically coincident with that by 2-D modeling technique, but there is a great difference between the results of 3-D and 2-D modeling for 3-D terrain. Project supported by the National Natural Science Foundation of China.     

中国东部寒武系与奥陶系界线地层的碳氧同位素研究

对我国东部不同地层区一些代表性的寒武系-奥陶系界线层位开展了碳?氧同位素研究?结果表明,由于沉积环境差异和成岩蚀变影响,界线层位的δ18O值变化较大,规律性不明显,δ13C值变化虽小,但在界线处均发生不同程度漂移?漂移的层位与寒武纪-奥陶纪主要生物群面貌变化的界线相一致?综合各方面资料分析,笔者认为,碳同位素组成的漂移很可能由晚寒武世到早奥陶世时期内海平面的升降所引起.     

深海二叠——三叠系界线研究现状

综述了深海二叠（Ｐ）－－三叠系（Ｔ）界线研究现状，介绍了深海Ｐ－Ｔ界线附近岩石地层，生物地层、缺氧事件及生物绝灭和复苏的研究进展，指出了深海Ｐ－Ｔ界线，缺氧事件和生物绝灭研究的分歧、不足及其症结。     

从层序地层学研究试论华北地区寒武系与奥陶系分界

华北地区寒武系－奥陶系过渡沉积可划分为三个层序：凤山层序、两河口－红花园层序和大湾层序，凤山层序与两河口－红花园层序之间的界面为Ⅱ型层序界面（ＳＢ２），而两河口－红花园层序与大湾层序之间的界面为Ｉ型层序界面（ＳＢ１）。华北地区寒武系－奥陶系界线应置于两河口－红花园层序的海侵体系域的下界面，在徐州地区为三山子组（狭义）与韩家组之间，在北京西山为韭园组微晶丘与冶里组之间。     

从综合地层学观点论华南浅海相泥盆系—石炭系的分界

生物地层学、事件地层学和层地层学综合研究表明，华南浅海相区与Ｓｉｐｈｏｎｏｄｅｌｌａｐｒａｅｓｕｌｃａｔａ带和Ｓ．ｓｕｌｃａｔａ带之间的界线相当的泥盆系－石炭系的界线不仅高于Ｃｙｓｔｏｐｈｒｅｎｔｉｓ带楔界，而且还应高于引起Ｃｙｓｔｏｐｈｒｅｎｔｉｓ绝灭的海退事件层的顶界。     

Seismotectonic environment of occurring the February 3, 1996 Lijiang M=7.0 earthquake, Yunnan Province

Introduction The surface rupture and aftershocks of the February 3, 1996 Lijiang earthquake are basically distributed along the N-S-trending Lijiang-Daju fault, which is boundary fault between Lijiang Quaternary, fault controlled basin and Yulong-Haba range (ZHANG, et al, 1997). Corresponding to the surface geological features, the focal rupture of the Lijiang earthquake also shows large component of dip-slip. It is of great difference from that of other earthquakes in west Yunnan, in w…