Hazard Zoning for Landslides Connected to Torrential Floods in the Jerte Valley (Spain) by using GIS Techniques

The Jerte Valley is anortheast-southwest tending graben located in the mountainous region of west central Spain (Spanish Central System). Mass movements have been a predominant shaping process on the Valley slopes during the Quaternary. Present day activity is characterized as either `first-time failure' (shallow debris slides and debris flows) or `reactivations' of pre-existing landslides deposits.A delineation of landslide hazard zoningwithin the Valley has been carried out by using the detailed documentation of a particular event (a debris slide and a sequel torrential flood, which occurred on the Jubaguerra stream gorge), and GIS techniques. The procedure has had four stages, which are: (1) the elaboration of a susceptibility map (spatial prediction) of landslides; (2) the elaboration of a map of `restricted susceptibility' in the particular case of slopes that are connected to streams and torrents (gorges); (3) the elaboration of a digital model which relates the altitude to the occurrence probability of those particular precipitation conditions which characterized the Jubaguerra event and (4) the combination of the probability model with the `restricted susceptibility map', to establish `critical zones' or areas which are more prone to the occurrence of phenomena that have same typology as this one.     

Effect of the chemical composition of the crust on the metamorphic evolution of orogenic wedges

Petrological data provide a good record of the thermal structure of deeply eroded orogens, and, in principle, might be used to relate the metamorphic structure of an orogen to its deformational history. In this paper, we present two‐dimensional thermal modelling of various subduction models taking into account varying wedge geometry as well as variation of density and topography with metamorphic reactions. The models clearly show that rock type accreted in the wedge has important effects on the thermal regime of orogenic wedges. The thermal regime is dominated by radiogenic heat production. Material having high radioactive heat production, like the granodioritic upper crust, produces high temperature metamorphism (amphibolitic conditions). Material with low radioactive heat production results in low temperature metamorphism of greenschist or blueschist types depending on the thickness of the wedge. Application of this model to seemingly unrelated areas of the Central Alps (Lepontine Dome, Grisons) and Eastern Alps (Tauern Window) explains the coexistence and succession of distinct Barrovian and blueschist facies metamorphic conditions as the result of a single, continuous tectonic process in which the main difference is the composition of the incoming material in the orogenic wedge. Accretion of the European upper continental crust in the Lepontine and Tauern Domes produces Barrovian type metamorphism while accretion of oceanic sediments results in blueschist facies metamorphism in the Valaisan domain.     

Orbitolinidae and Alveolinidae (Foraminiferida) from the uppermost Albian-lower Cenomanian of Monti d'Ocre (Abruzzi, Italy)

A biostratigraphic study carried out in the Monti d'Ocre area, Abruzzi, Central Apennines, allowed us to recognize Orbitolina (Conicorbitolina) moulladei ‘Strata 5 (1985) 1’, Praealveolina iberica Reichel and Praealveolina simplex Reichel in uppermost Albian–lower Cenomanian shelf-edge deposits of the Fossato Machè succession. These foraminifers have now been found for the first time in the Apennines of central Italy; their finding is quite important from a palaeobiogeographic viewpoint, as it contributes to the improvement of our knowledge on facies distribution in the circum-Mediterranean regions during the Cretaceous Period. In the study area, the coeval Monte Rotondo and Monte Orsello sections also crop out; these are characterized by bauxite deposits and stratigraphic gaps reflecting episodes of emergence on the carbonate platform. The Monte Rotondo and Monte Orsello sections accumulated in a platform back-reef environment; consequently, in this sector of the Monti d'Ocre area, the depositional environment shifted from a back-reef westward and southward to a shelf-edge northward, during the latest Albian–early Cenomanian. Owing to synsedimentary tectonics, the area investigated underwent differential subsidence: westward and southward, wide areas were uplifted and subjected to emergence, karstification and bauxite accumulation, whereas sedimentation continued in a shelf-edge environment in the north-eastern area.     

中心回线瞬变电磁法2.5维有限单元算法

瞬变电磁法的野外资料解释基本上停留在一维水平，本文从生产实践中常用的中心回线法入手，基于电磁场本身的叠加原理，从麦克斯韦方程组出发，导出了中心回线瞬变电磁2.5维二次场（纯异常）的有限单元计算公式. 该算法采用三角形有限元网格，在尽可能拟合地下电性断面的情况下减少有限元网格的节点数和单元数；用选主元的LU分解法求解线性方程组，做到了在移动场源时只需改变右端项；在反傅氏变换中，使用新的波数选取方案，让波数m随时间t滑动. 最后给出的算例表明，该算法直接计算异常场，计算速度快、精度高.     

东亚冬季风的演变特征

文章主要讨论了东亚冬季风和冷涌的演变特征，并与南亚作了对比，发现在东亚地区，冬季风演变主要表现为10月中旬经向环流的突变及9月初、11月中旬和1月末对流层低层温度的3次突变；而在南亚地区，经向环流的变化不如东亚地区明显，而且高层要先于低层变化，对流层低层温度存在2次突变。在整个冬季，东亚地区冷涌的演变过程，主要表现为南海地区冷涌在12月份出现最高频率，而西太平洋冷涌在1月份出现最高频率；南亚地区冷涌在12月份出现最高频率，但远小于东亚地区且衰减速度很快。另一个不同点是东亚地区的冷涌强度是往上衰减的，而南亚地区的冷涌强度则是往上增强的。这说明东亚冬季风和南亚冬季风的性质有较大的区别。     

新疆地表水资源对亚洲中部未来气候变化的响应

在未来的亚洲中中气候变冷过程中，从咸海干涸海底和卡拉博加戈尔湾等等内陆湖泊和地区吹起的盐粒，农田排出的农药残余物，尘埃微粒等－固态大陆型气溶胶具有主要的作用。在这一过程中，环流及该区域的生物系统对气候的变化可能起着相反的影响。     

新疆对中亚五国的外贸结构,问题及对策

本文在分析新疆对中亚五国的外贸结构基础上，阐述了目前在与中亚五国的贸易中存在的一些问题，提出相应的对策建议，以推动新疆与中亚五国外贸发展的良性循环。     

中国金银矿产资源现状成矿环境及开发前景

中国金银矿产具有类型齐全的共同特点，其资源和开发前景表现为金矿优于银矿。金矿成矿环境有利，成矿时代及资源分布广泛。但是，储量在１００吨以上的超大型矿床不多，富矿少，资源利用程度高，且浪费严重，存在重开发、轻勘查等问题。银矿虽然是世界上资源丰富的国家之一，但仍然是我国资源保证程度较低的矿种之一，也存在特大型矿床少、探明储量不足的问题。     

康滇地轴中南段铀成矿条件及远景分析

本文对康滇地轴中南段铀矿化划分出３种类型（砂岩型、钠交代岩型和元古代浅变质岩型），并阐明其主要特征。提出了元古代地壳演化曾经历了原始古陆形成阶段、沉降活动阶段和基底再团结阶段，认为中元古界昆阳群是有别于典型的含铀碳硅泥岩沉积建造。通过对该区部分岩石原始铀含量进行研究，提出了有关岩石可作为该区铀源岩的新认识；划分出碱性和酸性两大类型的热液蚀变，指出本区以发育碱性蚀变地段的成矿前景较好。指出该区铀成矿前景：（１）该区不具备形成澳加式元古代不整合面型铀矿床的地质条件；（２）非澳加式元古代不整合面型的铀成矿前景较差；（３）本区碱（钠）交代岩型铀矿化具有一定的找矿前景。     

The phytoplankton of some saline lakes in Central Asia

The Aral Sea, Lake Balkhash, and Lake Kamyslybas are closed lakes in Central Asia. They range from oligosaline to metasaline. The salinity of the Aral Sea has increased by more than 30 g L⁻¹ since widespread irrigation began in its catchment area. Few studies of the phytoplankton have been conducted on these lakes since extensive irrigation started. The investigation reported here compares the flora of phytoplankton in these saline lakes. In the Small Aral Sea, phytoplankton density gradually decreased with increasing electrical conductivity (EC) (∼ salinity), but there was no such relation in Lake Balkhash and Lake Kamyslybas. In the Aral Sea, Dinophyceae and Bacillariophyceae were frequently observed in most areas of high EC value, and Cyanophyceae were most conspicuous in the area of medium and lower EC values. In Lake Balkhash, Cyanophyceae were most conspicuous, but Chlorophyceae were also noticeable. Most Cyanophyceae in Aral Sea formed filaments with heterocysts. The distinct characteristic of the phytoplankton of the Lake Balkhash was that all dominant species form colonies covered with a gelatinous film. Siliceousplankton diversity gradually decreased with increasing EC values in the Aral Sea and Lake Balkhash.