中国北部及其邻区地壳上地幔三维速度结构

本文利用中周期和长周期瑞利面波资料分别反演得到中国北部及其邻区的三维Ｓ波带度结构。结果表明，地壳中横向非均匀性非常明显，许多地区显示出构造活动的特征；上地幔速度结构的横向变化相对减小。研究区的地壳厚度从东向西逐渐增大，地壳平均速度分布的格局与地壳厚度分布大体一致。地壳厚度与地壳平均速度的空变带处与布格重力异常梯级带基本一致。从数据上看，地壳厚度远比地壳平均速度与布格重力异常的一致性程度高，因此可以     

Some Splitting Methods for Equations of Geophysical Fluid Dynamics

In this paper, equations of atmospheric and oceanic dynamics are reduced to a kind of evolutionary equation in operator form, based on which a conclusion that the separability of motion stages is relative is made and an issue that the tractional splitting methods established on the physical separability of the fast stage and the slow stage neglect the interaction between the two stages to some extent is shown. Also, three splitting patterns are summed up from the splitting methods in common use so that a comparison between them is carried out. The comparison shows that only the improved splitting pattern (ISP) can be in second order and keep the interaction well. Finally, the applications of some splitting methods on numerical simulations of typhoon tracks made clear that ISP owns the best effect and can save more than 80% CPU time.     

乡村聚落地理研究的国外动态与国内趋势

本文根据国内外乡村聚落地理研究的内容变化和理论进展，初步划分了乡村聚落地理研究的主要发展阶段。在此基础上，结合国外乡村聚落地理研究的动态及我国乡村地区发展的现实，对我国乡村聚落地理研究进行了回顾与评价，并提出若干重点研究内容与趋势。     

重庆奉节天坑地缝喀斯特地质遗迹及发育演化

小寨天坑、天井峡地缝式喀斯特峡谷位于重庆市奉节县南部深切割峰丛谷地区,发育在一个流域面积280km2,落差1600m的喀斯特水文系统中,与巨大的地下河相连。前者深662m,口径626m,容积119×106m3,是目前世界上规模最大的天坑;后者长6162m,最大深度229m,最小宽度1m,为世界上罕见的地缝式喀斯特峡谷,具有很高的美学观赏价值和科研价值。天坑、地缝的形成条件,需要有连续沉积厚度巨大的碳酸盐岩层和平缓的岩层产状、高强度水动力作用地下河的存在、地表深切和地表地下排水基准面的长期大幅度下降、厚度相当大的包气带、地表与地下喀斯特作用协同等。天坑、地缝主要形成于峡谷期(三峡期),经历了3个演化阶段,即宽缓河流谷地阶段、峡谷及天坑地缝形成阶段和现代河谷持续深切阶段。     

盐边群地层特征及其大地构造属性

通过对盐边群各岩性段地层的产出、构造变形特征及相互问的接触关系的确认，在对碎屑岩组段进行颗粒骨架分析的基础上，结合已有的地球化学和同位素年代学研究结果，盐边群火山岩及其南侧的深成岩均不是蛇绿岩的组份．该火山岩可能形成于弧后伸展环境，盐边群中下碎屑岩段形成于弧后盆地，而上部碎屑岩段则可能形成于前陆盆地。研究表明，在华南板块西缘存在南北向格林威尔期的板块碰撞事件，盐边群地层可能记录了格林威尔期发生在华南地块西缘由弧后盆地到前陆盆地的整个演化历史。     

Major Characteristics of the Lajishan Orogenic Belt of the South Qilian Mountains and Its Geotectonic Attribute

The Lajishan orogenic belt is one of the E-W-trending Caledonian erogenic belts within the Qinling-Qilian orogenic system. It was formed upon the Jiningian basement by intensive taphrogenesis. Its major characteristics comprise the prominent faulting along the north and south boundaries, the highly complicated petrological and petro-geochemical features of the volcanic rock series, and the development of a new type of ophiolite suite. In terms of tectonic analysis and the sequential analysis of tectonic settings of magmatic rocks, it is suggested that the Lajishan orogenic belt has undergone a complete "opening-closing" cycle, which can be further divided into 3 second-order "opening-closing" cycles. The composite characteristics of the "opening-closing" movement show that Laji Mountain is a typical fault orogenic belt. The fault orogenic belt is one of the most important types of intracontinental orogens. It is of critical theoretical and practical significance to summarize the characteristics and the     

鄂尔多斯地区南缘奥陶纪层序地层及海平面变化

鄂尔多斯地区南缘奥陶纪可划分为１２个层序（ｓｅｑｕｅｎｃｅｓ）．本区奥陶纪地壳演化正处于重要关键时期，早奥陶世（冶里－亮甲山期、马家沟期、峰峰期）为被动大陆边缘，划分为７个层序．海平面突然上升，尔后逐渐下降．中、晚奥陶世（赵老峪期、上店期）演化为主动大陆边缘，可划分为５个层序．海平面就鄂尔多斯地区整体而言发生大规模海退，露出海面．但就鄂尔多斯地区南缘则海水突然加深，随后海平面渐渐下降．晚奥陶世卡拉道克世末鄂尔多斯地区海水全部退出．     

Low-grade metamorphism and geotectonic setting of the Macuchi Formation, Western Cordillera of Ecuador

Abstract The Cretaceous-Eocene basic to intermediate marine volcanic rocks of the Mucuchi Formation constitute the Western Cordillera in northern Ecuador. Their chemical features mostly correspond to those of tholeiitic basalts with some calc-alkaline affinities and suggest an oceanic island arc setting. The Macuchi rocks are affected by low-grade, non-deformative metamorphism, characterized by zeolite, prehnite-pumpellyite and lower greenschist facies assemblages. Depth-zonation is suggested by the downward mineral sequence: (i) laumontite+ (pistacitic epidote, pumpellyite + prehnite); (ii) pumpellyite+ prehnite + pistacitic epidote; (iii) actinolite+biotite+ pistacitic epidote + chlorite. This broad zonation and the chemistry of individual minerals point to an interaction between the volcanic rocks and sea-water under a moderate to high thermal gradient (= 75° C/km?). Alteration appears to have been dependent primarily on fluid control (volume, pressure, composition), temperature and reaction kinetics which together partly overshadow the role of load-pressure. Compositional variations of a mineral species at the scale of a contiguous flow or even at the scale of a thin section show that intensity of alteration was spatially uneven depending on rock permeability and consequently, metastable equilibrium commonly exists. However, a progressive approximation to equilibrium as a result of P–T control is shown by the mineralogy. A high f_o2 of the fluid phase is evident from the mineral chemistry. The metamorphism of the Macuchi volcanics is similar to the hydrothermal-burial type produced during the development of a volcanic arc where lavas and volcanoclastics accumulated in a shallow marine environment. However, some of its characteristics point to a transition toward systems defined by a higher T/P ratio such as those found in ocean-floor metamorphism. A model is proposed in which the Macuchi volcanics are assigned to an oceanic island arc generated contemporaneously with a marginal basin which has opened as the outcome of progressive north-south attenuation of the continental crust due to mantle diapirism.     

PRELIMINARY DISCUSSION ON METALLOGENESIS OF LANCANGJIANG RIVER TRANSITIONAL FIELD TECTONIC ZONE IN WESTERN YUNNAN

1 Concept of transitional field tectono-metallogenesis On the basis of preliminary systemical elucidating the concept of crustobody, while making ahistoristic-dynamic integrated metallogenetic analysis of the relation of the mantle creep-flow andgeothermal energy coacervation-diffusion alternation as the deep dynamic source and mechanismto the evolution and movement of crustobodies (including intrabody and interbody), Chen Guodaproposed the technical terms of transitional field tectono-met…     

内蒙古哈达门沟金矿成矿时代及成矿阶段研究

通过对哈达门沟金矿床不同地质体的同位素年龄测定。野外观察各地质体之间的空间关系，研究矿床中各种矿物的形成阶段。矿物之间的蚀变交代穿插关系，成矿物理化学条件的变化等，确定矿床的形成时代为华力西晚期，主成矿期可划分为金-石英-钾长石，金-多金属硫化物-石英，金-黄铁矿-石英，金-石英-碳酸岩4个阶段。