苏浙皖边界地区苏皖运动的有关问题

苏皖运动的存在于否,对研究苏浙皖边界地区的地质发展史和正确认识长兴阶地层有重要意义。笔者论证了长兴组的厚度变化、界线粘土层的性质与成因、底砾岩的确认和地层接触关系、古生物群的突变等问题,认为:1)区内苏皖运动是存在的;2)砺山-江阴海堤不可否定;将安徽广德牛头山经江苏宜兴至江阴条带内的龙潭组上部地层作为长兴组的相变产物是不妥的。      

信息科学与矿产预测

矿产预测实质上就是对成矿系统演化过程精确性表达的探索,现代信息科学的发展为理解成矿系统的非线性特性以及信息运动过程提供了必要的理论基础。通过信息与成矿信息、虚拟现实技术与成矿预测可视化和信息模型与成矿系统三个方面探讨信息科学的发展与矿产预测之间的紧密联系,预测未来成矿预测将向定量化、精细化的方向发展,对矿的定位预测从以分析为主向分析与综合相结合方向发展。     

陕北土地沙漠化及其防治区划

本文对陕北榆林地区土地沙漠化划分了四种类型及描述了沙漠化土地分布的特点,并对这一地区的沙漠化土地进行了防治区划,为全区制定综合农业区划提供科学依据。沙漠化是土地在自然和人为因素作用下,植被和土壤逐渐衰退破坏导致沙地出现的过程。当今,沙漠化迅速发展和扩大的特征是以人口的迅猛增长及滥用土地为主要标志,它所带来的对人类生活及环境的威胁,正越来越引起人们的重视。陕北地区是我国沙漠化严重地区之一,研究其发生发展的历史和现状,预测其发展趋势,从而制定沙漠化土地的治理区划,对本区沙漠化土地整治和预防具有重要意义。     

沙子口湾海岸侵蚀原因及防治对策研究

通过实测水文资料、岸滩冲淤变化规律和泥沙动态研究沙子口湾近３０ａ来的变化,分析湾顶海滩侵蚀的原因,对现有的海岸工程进行调查,研究海岸防护对策,分析海岸防护工程的可行性。     

关于建立测绘技术进步指标体系框架的探讨

本文从技术进步的基本理论出发,结合测绘生产单位的实际情况,研究和探讨如何在测绘系统内建立测绘技术进步指标体系的一些框架内容。希望对测绘管理和规划部门有所帮助。     

Winter Temperature Variability During Warming and Cooling Periods in the Conterminous United States, 1947–1992

Summary  Much literature has reported on the concept of increased surface temperature variability during cool periods, although analyses on temperature records have rendered inconsistent results. In addition, temperature variability during transition periods has been rarely investigated. This study examines temperature variability during wintertime cooling (1947–1977) and warming (1978–1992) periods for the conterminous United States to determine both whether temperature variability is different during warming or cooling periods, and whether the change in variability is supported by midtropospheric circulation conditions. Our results indicate that regions with high temperature variability are mostly found below the troughs in the midtropospheric pressure fields. The direction of change in temperature variability corresponding to cooling or warming conditions, however, varied spatially. For the southeastern and northeastern United States, winter temperatures were more variable during the cooling period than during the warming period, while the northern and central Great Plains had greater temperature variability during the warming period than the cooling period. Similar spatial patterns are also found for the changes in the variability of geopotential height fields. Such spatial patterns in the temperature and height variability during warming and cooling periods may be related to the dominant midtropospheric circulation patterns, such as the different phases of the Pacific-North American teleconnection pattern, and the El Ni?o/Southern Oscillation events. It is concluded that the response of interannual temperature variability to climatic changes is determined by the variation in circulation patterns, and therefore, not spatially uniform. Received September 26, 1996 Revised April 2, 1998     

江西雅山花岗岩长石中磷的分布及意义

雅山富氟高磷花岗岩具较高的全岩磷含量（０．１５％～０．５５％）,长石是磷的主要赋存矿物,磷以ＰＡｌＳｉ－２替换方式进入长石结构中。各种结晶习性的长石的磷含量各不相同。早世代钠长石和雪球结构中钠长石包裹体的结晶较早,平均磷含量分别为０．１８％和０．１９％,而晚世代钠长石和环带钾长石中钠长石嵌晶的结晶稍晚,具较高的平均磷含量（分别为０．２５％和０．２３％）。钾长石的磷含量相对于钠长石总体上较低,早期结晶的雪球结构主晶钾长石和环带钾长石的磷含量最低,分别为０．０４％和０．０２％,晚期细粒钾长石的平均磷含量略高（０．１９％）。长石对全岩磷的贡献率还与磷锂铝石等磷酸盐副矿物是否达到饱和有关,当无磷锂铝石结晶时,长石磷的贡献率约为７６％,反之则约为３１％。     

西藏措勤地区中生代的构造变形

：１∶１０万野外地质填图发现,在措勤地区北侧的白垩系中发育了一系列逆冲推覆构造和褶皱构造,且有侵入岩体分布,又被未变形的火山凝灰岩不整合覆盖。根据侵入岩的钾长石和角闪石及其不整合的火山凝灰岩中蚀变斜长石的ＡｒＡｒ法同位素年龄、沉积物质的组成和沉积地层的空间展布等特征,笔者推测这些逆冲断层和褶皱构造均发育于晚白垩世,并早于第三纪。     

非开挖可控冲击矛轨迹变化的试验研究

冲击矛技术作为非开挖技术的一个重要手段,由于其自身所具有的一些优势而被广泛采用。但是,冲击矛从其形成产品到现在,在施工时方向是不可控的,而可控冲击矛目前国内外还没有成形产品。欲使冲击矛的钻进方向可控,可以改变冲击矛的方向,使钻头轴线与冲击器轴线存在一定夹角是一个有效的办法。影响可控冲击矛轨迹变化的因素很多,由于目前没有成形冲击矛,因此,制做可控冲击矛的模型来进行模拟试验。通过试验去发现可控冲击矛轨迹的曲率半径变化与上述各种影响因素之间的关系,并通过建立数学模型来说明。     

Seismotectonic Environment for Zhangbei-Shangyi Earthquake and Characteristics of Macroscopic Damage

The regional seismotectonic environment for the Zhangbei- Shangyi earthquake is described, and in combination with the distribution of macroscopic seismic intensity, source mechanism solution, and interpretation of lineaments on satellite images, the seismogenic structure for the earthquake and possible seismogenic fault are discussed in this paper. It is suggested that the Zhangbei-Shangyi earthquake is a result of the latest movement along the northwestern termination of the Zhangjiakou-Penglai fault zone and we should pay serious attention to the future trend of seismic activity along this fault zone.