中国地表植被覆盖变化及其与气候因子关系

本文利用１９８５－１９９０年连续６９个月的ＮＯＡＡ时间序列数据,进行中国植被覆盖变化的空间,以及时间序列分析,并且结合同期的平均气温,降水数据,进行植被覆盖变化与气候因子相关性分析,该文证实了在中国植被覆盖随时间的推移规律,空间分布规律,以及植被覆盖变化与气温,降水的定量关系。     

榴辉岩中绿辉石的测定方法研究

通过对某地榴辉岩中伴生的有用矿物的纯矿物物质组成的研究,发现Ｎａ可作为其中绿辉石的特征性成分,且Ｎａ２Ｏ含量与其纯度呈正相关。因此,推荐用测定Ｎａ２Ｏ量并以求得的换算系数计算榴辉岩中绿辉石含量的化学物相分析方法。经合成样品验证,方法的相对误差＜１．７％,用于生产样品分析,所得结果的重现性好,平均偏差＜０．５％。     

矿床成矿系列研究的若干问题与方向——兼论非金属矿床成矿系列研究的有关问题

矿床成矿系列研究是当前区域成矿学研究的重要内容。自70年代末提出矿床成矿系列的概念以来,矿床成矿系列的研究无论在金属矿床方面还是在非金属矿床方面都已取得重要进展。笔者对比了非金属矿床与金属矿床成矿系列的概念、层次划分、分类、研究内容和命名,分析了矿床成矿系列研究的现状,并讨论了矿床成矿系列研究存在的问题。笔者认为,成矿系列的概念应予统一,在层次划分和分类上应有统一的标准,还应考虑到金属矿床与非金属矿床的统一性和差异性。     

淮河流域洪涝变化吸引子维数研究

淮河流域洪涝序列的功率谱表现出了较好的混沌谱特征,这是序列呈分形结构的内在原因。洪涝序列及其不同平滑序列的关联维数表明,序列平滑程度越大,关联维数越小,关联维数反映了序列所在系统的层次,是系统结构复杂性的重要量度,是 系统建模所需独立变量的控制参数。要恰当地描述淮河流域洪涝发生系数,需构造至少５个状态变量的动力学系统。     

Analysis of seismic dynamical systems

A procedure is presented for the analysis of complex stationary time series for which the Fourier power spectra reveals broadband noise or broadened pulses. We first determine the Hurst exponent from which we may know whether the time series under study is mainly random or if the data points present correlations. If the data are correlated, a chaotic analysis will reveal whether they may be interpreted as a low dimensional nonlinear system (defined by a low correlation dimension and a finite and positive Kolmogorov entropy and largest positive Lyapunov exponent) or as a stochastic process. We have studied three kind of temporal series: inter-event time series of infrasonic pulses recorded at Stromboli volcano, and, S-coda waves and microseisms, that have been recorded at the eastern Pyrenees. Results show that microseisms and Coda waves can be modeled as a low dimensional deterministic system, Correlation dimensions 2.3, 3.2, respectively. At the contrary infrasonic has resulted stochastic. This chaotic character can be attributed to the medium properties. Coda waves with scattering through a fractal distribution of scatters or to multiple reflection inside resonators (for example sedimentary basins) and microseisms as a propagation of wave guide of variable cross section which have the same temporal characteristics as a nonlinear forced oscillator.     

Metallogenetic characteristics of an unique uranium-tungsten mineralization zone

A polymetallic zone dominated by U-W mineralization was found in Northeast Guangxi. Distributed along the east contact zone of a complex granite mass, it extends for about 100 km in length, with more than fifty deposits and prospects embraced. The deposits show a wide range of genetic types, related to the granite, from magmatic (including pegmatite and skarn deposits) through hydrothermal mineralizations (hypo-, meso- and epithermal) all the way to tin placers, constituting a very intact metallogenetic series of granites. The epithermal U-W deposits are considered as a new type for their unique geological and geochemical characters, such as the paragenesis of U and W and the large time gap (> 40 Ma) between ore and granite. This project was financially supported by the Open Lab. of Ore Deposit Geochemistry, Chinese Academy of Sciences.     

非迭代,非线性二维重力反演计算方法

本文叙述了非迭代、非线性二维重力反演方法的原理、模型计算及应用效果等。与以往诸多的求界面重力反演方法相比,该法的主要特点是：将界面的深度用一幂级数的形式表示,且幂级数系数的计算与界面上下地层的密度差无关。因此,一旦求出了幂级数的系数,由界面的密度差可直接得到界面的深度,且幂级数收敛的速度很快。     

新疆阿尔泰造山带矿床成矿系列

在系统分析阿尔泰造山带成矿区（带）地质构造演化和成矿特点基础上,划分了４个矿床成矿系列、４个矿床成矿亚系列和６个矿床式。矿床成矿系列和亚系列的形成和分布受区域构造岩浆演化制约。阿尔泰造山带矿床成矿系列具有鲜明的晚古生代成矿作用特点。区域构造演化的规律和后期构造对早期构造的叠加,决定了矿床成矿系列的规律分布和局部复合。     

Mesozoic Granitoid Types and Metallogeny of the East China Circum-Pacific Continental Margin

Abstract: This paper synthesizes the geotectonic background, genetic types and metallogenetic relations of the Mesozoic granitoids in the East China continental margin. By the Mesozoic, the Siberia Plate, North China Plate and South China Plate amalgamated together, resulting in formation of a unified Eurasia super–continent. Since the late Triassic to early Jurassic period, the territory of East China gradually became a Cordilleran style active continental margin. During the Jurassic to early Cretaceous (early to middle episodes of Yanshanian orogeny), the Paleo-Pacific plate strongly collided with and subducted under the Eurasia continent, reactivated the consolidated East China continental margin. The granitoids of both transformation series and syntexis series were generated. Many granitoid-related large and giant metal deposits were formed. Furthermore, the W, Sn, Be, Nb, Ta and U mineralizations are mostly associated with the transformation series; while the Fe, Cu, Mo and Au mineralizations are mostly associated with the syntexis series. The late Yanshanian orogeny (late Cretaceous) began a transition to the western Pacific style continental margin. A tensional environment resulted in development of alkaline granitoids and formation of continental red basins. The Cenozoic orogeny was characterized by a backarc spreading and rifting regime in this region.     

甘肃敦煌地区太古宙孔兹岩系特征

本文根据甘肃敦煌地区广泛出露在太古宙TTG杂岩中的一套副变质岩系的岩石组合、典型矿物组合、变质相特征和岩石化学特征的分析,认为它们是一套中深变质的碎屑岩-泥质岩-泥灰岩-碳酸盐建造,其中夹有少量的变质基性火山岩。原岩形成于具有基性火山作用的活动大陆边缘滨海-浅海环境。经过太古宙的区域高角闪岩相变质作用,形成孔兹岩系。