家乡的北大河

儿时的记忆最清晰的，是家乡的北大河。北大河从村子中间通过，由北向南，河面长有1000米，宽足够200米，不知道是哪儿的源头，也不知流向哪里。只知道从村外来又流向村外去。现在明白了，北大河的源头就是村外的泉水和河中无数的泉眼，流到村外的沟沟岔岔。所以老人们说，北大河是家乡的河。     

天津泰达地区粉土振动液化特性的研究

本文以动三轴试验和原位测试数据为基础，以天津地区砂性土为例，探讨砂性土振动液化机理及孔隙水压力变化规律，采用多种方法分析判别砂性土液化，为高烈度地区重要工程建筑抗震设计提供重要数据。     

土工带加筋碎石土本构关系的三轴试验研究

通过碎石土和加筋碎石土的大型三轴试验,分析了土工带加筋碎石土的变形特性和土工带加筋对碎石土应力-应变关系的影响,采用双曲线函数拟合加筋土体的应力-应变试验曲线,建立了土工带加筋碎石土的非线性模型以克服经典的刚塑体模型不能反映加筋土体在达到破坏荷载前的变形形态的缺点,提出了土工带加筋土体切线模量的计算公式,该模型能正确反映土工带加筋土体的变形特性,在岩土工程方面有一定的实际应用价值.     

Hydrothermal Mineralization on the Mesoproterozoic Passive Continental Margins of China： A Case Study of the Langshan-Zha＇ertaishan Belt, Inner Mongolia, China

Most ore-forming characteristics of the Langshan-Zha‘ertaishan hydrothermal exhalation belt, which consists of the Dongshengmiao, Huogeqi, Tanyaokou and Jiashengpan large-superlarge Zn-Pb-Cu-Fe sulfide deposits, are most similar to those of Mesoproterozoic SEDEX-type provinces of the world. The characteristics include: (1) All deposits of this type in the belt occur in third-order fault-basins in the Langshan-Zha‘ertaishan aulacogen along the northern margin of the North China Platform; (2) these deposits with all their orebodies hosted in the Mesoproterozoic impure dolomite-marble and carbonaceous phyllite (or schists) have an apparent stratabound nature; ores display laminated and banded structures, showing clear depositional features; (3) there is some evidence of syn-sedimentary faulting, which to a certain extent accounts for the temporal and spatial distribution and the size of the orebodies in all deposits and the formation of intrabed conglomerates and breccias; (4) they show lateral and vertical zonation of sulfides; (5) The Cu/(Pb Zn Cu) ratio of the large and thick Pb Zn Cu orebodies gradually decreases from bottom to top; and (6) barite is interbedded with pyrites and sometimes with sphalerite. However, some characteristics such as the Co/Ni radio of the pyrites, the volcanism, for example, of the Langshan-Zha‘ertalshan metallogenic belt, are different from those of the typical SEDEX deposits of the world. The meta-basic volcanic rock in Huogeqi, the sodic bimodal volcanic rocks in the Dongshengmiao and potassic bimodal-volcanic rocks with blastoporphyfitic and blasto-glomeroporphyritic texture as well as blasto-amygdaloidal structure in the Tanyaokou deposits have been discovered in the only ore-bearing second formation of the Langshan Group in the past 10 years. The metallogeny of some deposits hosted in the Langshan Group is closely related to syn-sedimentary volcanism based on the following facts: most of the lead isotopes in sphalerite, galena, pyrite, pyrrhotite and chalcopyrite plot on both sides of the line for the mantle or between the lines for the mantle and lower crust in the lead isotope composition diagram; cobalt content of some pyrites samples is much higher than the nickel content (Co/Ni= 11.91-12.19). Some volcanic blocks and debris have been picked out from some pyritic and pyrrhotitic ores. All Zn-Pb-Cu-Fe sulfide orebodies in these deposits occur in the strata overlying metamorphic volcanic rocks in the only ore-bearing second formation. In the Jiashengpan deposit that lacks syn-sedimentary volcanic rocks in the host succession only Pb and Zn ores occur without Cu ore, but in the Dongshengmiao, Tanyaokou and Huogeqi deposits with syn-sedimentary volcanic rocks in the host succession Cu ores occur. This indicates a relatively higher ore-forming temperature. The process of synsedimentary volcanic eruption directly supplied some ore-forming elements, and resulted in secular geothermal anomaly favorable for the circulation of a submarine convective hydrothermal system, which accounts for the precipitation of deep mineralizing fluids exhaling into anoxidic basins along the syn-sedimentary fault system in the Langshan-Zha‘ertai rift. The Dongshengmiao, Tanyaokou, and Huogeqi deposits hosted in the Langshan Group appear to be a transitional type of mineral deposit between SEDEX and VMS-types but with a bias towards SEDEX, while the Jiashengpan deposit hosted in the Zha‘ertai Group is of a characteristic SEDEX type. This evidence, together with other new discoveries of Mesoproterozoic volcanic rocks and the features of lithogeny and metallogeny of the Bayun Obo deposit in the neighborhood emphasize the diversity, complexity and uniqueness of the Mesoproterozoic Langshan-Zha‘ertal-Bayun Obo ore belt.     

新疆北天山中东段地区震源参数研究

本文首先利用经验格林函数方法证明了新疆北天山中东段地区的震源谱基本满足ω-2 模型。在此基础上 ,通过对S波观测谱中的噪音、仪器、路径、场地等影响的逐一消除 ,得到了研究区 10 5次ML2 5～ 5 7地震的震源谱 ,进而根据Brune的圆盘震源模型计算了地震矩、应力降、震源半径等震源参数。结果表明 ,这些地震的标量地震矩M0 与ML 震级线性相关较好 ,关系为Log10 M0 =1 10ML+ 17 2 0 ;震源半径在 10 0～ 15 0 0m之间 ;应力降介于 1～ 16 0bar之间 ,优势分布于 1～ 10 0bar。地震矩与拐角频率的关系呈现出两段趋势 ,可能表明了研究区震源的多重标度特征 :当M0 小于 4× 10 2 1dyne cm时 (相当于ML4 0地震 ) ,应力降显示出对M0 有依赖关系 ;当M0 大于 4× 10 2 1dyne cm时 ,地震的应力降不依赖于M0 。     

北秦岭造山带加里东期低Al-TTD系列: 岩石特征、成因模拟及地质意义

北秦岭存在一套低Al的奥长花岗岩-英云闪长岩-闪长岩系列岩石, 其形成时代在430~399 Ma之间, 并具有正ε_Nd(t)特征. 地球化学特征和微量元素模拟计算表明, 它们由二郎坪群中的变拉斑玄武质岩石重熔而来, 不同残留相和熔融程度形成了不同岩石类型. 重熔过程残留相的热力学分析显示, 该岩石系列代表温度升高、压力降低的过程, 表明存在加厚地壳的拉张减薄作用.     

北黄海盆地构造几何学研究新进展

北黄海盆地是发育于隆起背景之上的中、新生代沉积盆地。新一轮资源调查研究表明，北黄海中、新生代沉积盆地的基底由古生界沉积岩层和前寒武纪变质岩系等组成，盆地不同程度地发育下构造层（J3-K1）、中构造层（E2-E3）和上构造层（N）；从油气资源和中、新生代地层发育情况出发，将北黄海海域划分为辽东-海洋岛隆起区、北黄海盆地和胶北．刘公岛隆起区等3个一级构造单元，其中北黄海盆地包括6个二级构造单元和24个三级构造单元；盆地褶皱、断裂构造十分发育，褶皱构造可划分为区域挤压型、局部伴生型和披盖型等三类，断裂构造主要可见近EW—NE向、NW向和NNE向三组，其中近EW—NE向和NNE向断裂比较发育，控制着盆地隆、坳分布格局和沉积特征。     

北祁连山白山子花岗闪长岩成岩时代

寒山大型金矿是近年来在北祁连山西段发现的与侵人岩有关的构造蚀变岩型金矿。笔者首次利用锆石U-Pb方法测得白山子花岗闪长岩的形成年龄为370±25 Ma，属于华力西期。寒山金矿的成矿主要在213.95~339 Ma间。在多期热液叠加，多期成矿作用中，早期成矿的热液很可能是白山子花岗闪长岩（370±25 Ma) ,寒山辉长岩(347.1±6. 4 Ma）共同提供的。由于该区有较多的中酸性岩体存在，它们可能为金的主要来源，因而，确定这些侵入体的形成年龄，对于在该区寻找蚀变岩型金矿不仅有重要的理论意义，而且有重要的现实意义。