Earthquake migration in East Asia mainland (I)—The migration of huge earthquakes and volcanic activity from West Pacific Trench to the Chinese mainland

The researches in this paper disclose a huge earthquake migration series that lasted more than one century—from the 17th century to the early day of the 18th, transverse migration of huge earthquake from West Pacific trench to the Chinese mainland, lasted about 134 a, the distance is about 2600 km, the velocity is about 19 km/a, and the direction of migration agrees with the direction of plate subduction and vertical to the strike of plate boundary. The migration has two branches. One extends westwards and terminates at the central longitude belt (Helanshan—Liupanshan fault zone) of the Chinese mainland, triggered the strongest seismicity episode in North China, including 4 earthquakes withM ⩾8.0. The other extends northwards, passing through Korea Peninsula, terminates at the north part of Heilongjian Province, and triggered the volcanic eruption activity in Changbaishan and Wudalianchi. The time-space linearity of migration is good. Its velocity is stable and its activity attenuates gradually. It is estimated that it is related with the disturbance of asthenosphere matters caused by the sudden acceleration of the subduction of the trench plate. There are two similar transverse migration series from 1498 to 1556 and from 1843 to 1927, and the velocities are 36.2 and 33.7 km/a respectively.     

西准噶尔地区加依尔山石炭纪地层中外来岩块的发现及其地质意义

通过在加依尔地区中—上石炭统太勒古拉组发现的外来岩块,查清了该区泥盆纪和石炭纪化石共生的原因,为确定该地区地层时代提供了佐证,并对研究本区石炭系的形成环境及区域构造演化等均将有新的启示.     

边眼虫属在新疆西准噶尔地区的发现

在新疆西准噶尔地区塔尔巴哈台山首次发现边眼虫属的一个新种,定名为Plagiolariaeminensis Guo (Sp.nov.).化石产于中泥盆统库鲁木迪组下部.     

安徽大别山蛇绿岩特征及其形成的大地构造环境

在安徽境内大别群中出露一系列镁铁质和超镁铁质岩体,属于“肢解的蛇绿岩”。与大别群建造应属同一造山期产物。它们可能在中元古代末期,因洋壳海域的岩石圈断块沿华北断块南部的大陆边缘的深海沟向北快速俯冲消减,遭到强烈挤压破碎而侵位到大别群不同构造层位中。     

鄂东南多层次滑脱拆离及其与桐柏-大别山滑脱拆离的对接关系

江汉盆地南北分别耸峙着幕阜山和桐柏—大别山。两大山脉均由前震旦系为核以震旦系、古生界、中新生界为翼组成复式背斜。两大复式背斜均以多层次滑脱拆离为特色。幕阜山北侧鄂东南构造自南而北,桐柏—大别山南侧构造自北而南向着江汉盆地滑移,并于江汉盆地对接。幕阜山复式背斜北翼的滑脱拆离构造平面上分为后缘拉伸带、中部滑脱带、前缘挤压带。对接带东段呈北西向,西段呈近东西向;东段以逆冲断层的对冲式对接,西段以褶皱式对接。表层拆离主要原因是重力滑动,基底拆离的原因仍待探讨。滑脱拆离发生于印支—燕山期。印支—燕山期的褶皱作用、山脉隆起、区域拆离滑动是相继而统一的过程,并与伸展作用密切相关。     

太白维山山前断裂活动特征的初步研究

本文立足于大量的野外第一手资料，综合解剖了太白维山山前断裂的几何结构，并就其运动学特征进行了初步探讨。认为：太白维山山前断裂第四纪以来的活动表现为正断型，其几何结构和运动特征都有着相同的分段性。我们将其划分为三段，西段结构简单，晚更新世以来无明显活动；中段结构复杂，一直强烈活动；东段活动强度较低。晚更新世晚期以来断裂（中段）的平均滑动速率０．４ｍｍ／ａ，全新世以来达到０．６７ｍｍ／ａ，而且这种速率     

Geomorphic effects of a large flood on fluvial fans

The response of 12 fluvial fans near Sydney, Australia to a large storm between 2 and 4 February 1990 was determined by repeating previously surveyed longitudinal profiles and by undertaking detailed field observations of erosion and deposition. Peak rainfall intensities occurred on 3 and 4 February when between 173 and 193·8 mm were recorded. Return periods for 24 h duration peak rainfall ranged between 5·7 and 11·0 years on the annual maximum series at six stations within the study area and return periods for 48 h peak rainfall ranged between 13·5 and 29·4 years. Of the 12 fans, seven were trenched and five untrenched. The most significant geomorphic effects of the storm were recorded on the proximal region of the fans. However, fan response was highly variable, with one fan exhibiting no detectable change, three fans localized deposition, two fans spatially disjunct erosion and deposition, two fans channel avulsions, and seven fans fanhead trench reworking. Some fans exhibited more than one type of response. A four-stage, tentative cyclical model of fanhead development was constructed from the field data. Stage 1 refers to the episodic aggradation of the fanhead by localized deposition, spatially disjunct erosion and deposition and/or channel avulsions. Stage 2 represents the initiation of a fanhead trench when progressive aggradation locally exceeds a threshold slope leading to localized erosion. This erosion initially creates one or more discontinuous flow-aligned scour pools. Over time, the scour pools widen, deepen and extend both up- and downfan. Stage 3 refers to the coalescence of discontinuous scour pools into a continuous trench by the removal of intervening log and boulder steps. Stage 4 represents the backfilling phase of the trench once it has been overwidened and/or slope reduced. Aggradation then continues as for stage one.     

利用山地凉夏水热资源发展城市淡季蔬菜

我国幅员辽阔，山地遍布，气候资源丰富，气候类型复杂．充分地利用山地凉夏水热资源，发展山地蔬菜，不但可以引导山区农民脱贫致富，而且可以解决城市蔬菜秋淡问题．     

意大利的泥石流研究

泥石流是意大利山区（尤其是境内阿尔卑斯山区）的一种主要山地灾害。从水力学和地貌学角度，综述了意大利的泥石流研究现状和进展，简介了一些有广阔前景的泥石流研究方法，如泥石流仪器监测法和泥石流起动过程的地质技术分析法，另外概述了三个有代表性地点的泥石流研究实例．     

山岳风景区客流研究：以安徽黄山为例

山岳风景区在我国旅游资源中占有重要地位，已有相当规模的客流量。因此，山岳风景区客流研究重要性日趋明显。笔者以安徽黄山为例，进行山岳风景区客流基本规律研究，揭示了山岳风景区客流时空分布的基本特征；预测了未来客流规模；探讨了客流对旅游环境的影响；提出了山岳风景区旅游发展的基本思路。