软土性质及其地基加固技术研究概况

本文通过文献检索，介绍了我国沿海地区广泛分布的软土的工程地质性质、变形与强度、触变性，基坑开挖及软土地基加固技术的发展概况，并对某些问题进行了讨论。     

论华北地区的均衡状态(一)——方法和局部补偿

根据经典均衡的原理,本文重点分析了五种局部均衡补偿模式.在计算方法上利用频域三维重力场的理论公式,快速求得均衡校正值,据此计算了66个模型的均衡重力异常场,注意到对这许多不同参量的模型而言,它们的均衡异常场在形态与分布特征上基本一致,其中计入了地表和上下地壳密度差异分布的 Airy 模型具有最佳的补偿效果,它的均衡面在莫霍界面以下的上地幔中,标准深度50km.从整体上看,华北地台处于亚均衡状态,均衡异常的均值为1810-5m/s2.均衡重力异常的分布表现出明显的块体特征,正均衡异常区主要分布在东部胶辽地块和冀中平原北缘,在汾渭裂谷区存在负异常.模型对比表明,以莫霍界面作为均衡补偿面的模型是不可取的;Airy 模型比 Pratt 模型的补偿效果略好,这同地壳构造以层状为主而侧向变化有限的特征相符.有关复合补偿、均衡重力异常的基本特征和深部构造的关系等结果,将在文章的第二部分发表.      

鄯善地区3-----5月次日浮尘的预报

浮尘是鄯善地区主要天气现象之一,同大风、雷暴等一起,严重危及飞行训练的安全,影响飞行任务的完成.浮尘受季节性变化很明显,春季是鄯善地区出现浮尘的旺季.本文取1985年3-5月共92天天气资料作为样本,用权重回归的方法作次日06-08时有无浮尘的尝试性预报.所选用的因子是根据气象学原理和预报员的经验引入的. 样本资料统计:凡次日06-08时有小于     

根据钻孔崩落椭圆确定唐山地区深部地壳应力方向

本文论述了钻孔崩落椭圆与地应力之间的关系,指出崩落椭圆的形成,是由于孔壁附近应力集中而引起的崩落现象,其长轴方向与最小水平主应力方向相平行。 根据在唐山地区2000—4000米深度范围内的三口石油钻孔中的测量结果,得出钻孔崩落椭圆的平均长轴方向为 N 7°W,由此确定的区域地壳最大水平主应力方向为 N 83°E。 最后,我们把钻孔崩落椭圆的结果同该区的震源机制、地应力解除和水力压裂的结果进行了比较,表明均具有良好的一致性。     

四川渡口地区晚第四纪沉积物的孢粉分析及其地质意义

作者在四川渡口地区选择了桐子林、金江火车站、盐边新村三个露头剖面,做了系统的孢粉取样及分析。本文就分析结果,讨论了本区第四纪地层的划分、对比及古环境等方面问题。     

唐山(1976)和三河——平谷地震(1679)附近的地应力场特征

本文讨论了唐山(1976)和三河-平谷地震(1679)附近的地应力场特征,发现位于震中附近的测点,其应力值比较低,而离开震中以远的测点则应力值比较高.同时还讨论了在唐山市凤凰山和顺义吴雄寺(三河-平谷地震附近)连续几年的测量结果,表明这两个地区震中附近的主应力值随时间变化的幅度不大,而它们的主应力方向随时间则有明显地变化.最后分析了引起震中附近低值应力的原因,并指出研究低值应力异常对地震预报的意义.      

台风下层的暴风

1982年8月,日本群马县的榛名山、赤城山以及日光白根山等地遭到台风下层暴风的袭击,大量珍贵树木被暴风刮倒,灾情十分严重。这次灾害是由当年10号台风造成的。1982年8月1日21时,10号台风从纪伊半岛东南约100公里的海面北上,2日00时在爱知县渥美半岛西部登陆,登陆时的中心气压为970毫巴,最大风速达30米/秒。以后,台风通过岐阜县、能登半岛西部,然后离开日本海。这次台风所遭成的灾害很严重,日本东部海面、日本中部和关东各地遭受了很大的损失。一般地说,台风在其移动方向的右侧风力较强,这次台风也不例外。从地面记录来看,群马县榛名山附近的前桥最大风速为19.1米/秒,最大瞬时风速达36.4米/秒;轻井沢最大风速为9.8米/秒,最大瞬时风速为27.2米/秒。1小时雨量最大     

祁连山白银厂黄铁矿型矿床成因探讨

The Baiyinchang mining area, an important industrial base of base metals in China, consists of five pyrite type deposits of different sizes, four of which have already been worked. These five deposits might be grouped into two types: Cu-bearing (predominatingly Cu) pyrite type deposits, such as Zheyaoshan, Huoyanshan and Tongchanggou, and polymetallic pyrite deposits containing principally Cu, Pb and Zn, such as Xiaotieshan and Sigejuan. These two types of deposits occur close to each other in the same formation-Baiyinchang spilite-keratophyre sequence and have similar structures and petrofacies, suggesting the possibility of forming two different types of deposits in the same tectonic unit and volcanic rock series. The deposit lies in the eastern part of the volcanic complex within the Qilian eugeosyncline, its genesis remains a problem of much controversy. Ln recent years, the author has made an integrated study and analysis of the data accumulated over the past thirty years and also performed some field investigation to check up these references. The results acquired have led him to postulate the hypothesis that the deposit was formed by the concentration of volcanic hydrothermal fluids in depression and the activity of subvolcano-magmatic fluids. The formation of the massive pyrite in the main ore body of Zheyaoshan is believed to be the result of the lateral effusion from the Qingshanbao vent of the third subcycle appearing presently as silicic rock formation, i.e., the result of the accumulation in the second subcycle crater depression of the ore material effused from the pyrrhotite ore chimney. This might be borne out by the existence of abundant massive copper-bearing pynhotite ore with well-developed textures of corrosion and replacement in the chimney as well as by the ring-like distribution of the metallic minerals around the chimney caused by the spread of the fluids from this center. Geological mapping and analyses of the data of drill core and petrofacies support the claim that the ore body is located at the crater depression. Minerals in massive pyrite ore body are coarse in the west and fine in the east, suggesting also the migration of ore fluids from east to west into the center of depression. The massive ore body cutting obliquely the strata, the relatively weak alteration of country rocks and the remarkable variation in copper content of the ore body all seem to have resulted from the ascending movement of the copper-bearing ore fluids brought by subvolcanic activity along the ore chimney and its fracture zone formed during the crustal reversion. The Xiaotieshan polymetallic pyrite deposit is of subvolcano-magmatic fluids type. Its ore-forming processes were strictly controlled by late subvolcanic activity which, in turn, was governed by fracturing. The ore body overlies the hanging wall of quartz albitophyre and shows close relationships with subvolcanic rocks in dimension and grade while the texture and structure of ore and the mineral constituents vary in accordance with the diverse country rocks. The examination of the structure of volcanos, fractures, variation in petrofacies, regularity of subvolcanic activity, the extent of wall rock alteration and characteristics of mineralization, therefore, makes up the prerequisite for the search of such concealed ore deposits. The Jinfangou ore belt expends along a EW striking fracture zone characterized by complex lithological characters and petrofacies as well as by frequent subvolcanic activities. Mineralization and ore bodies are exclusively confined to the fracture zone. The repeated crustal reversion during: the late stage of the development of rock formation resulted in the folding and faulting of the strata, thus facilitating the differentiation and migration of the magma. The intrusion of the subvolcanic magma not only brought sufficient ore-bearing fluids for mineralization, but supplied heat for their migration. This is due to the fact that heat: accelerated the circulation of the ore fluids, which dissolved ore elements dispersed in the volcanic rock and unceasingly infiltrated into and replaced the country rocks as well. As a result ore fluids concentrated to form ore deposits at places with favorable structure and country rock conditions.     

天津云杉孢粉组合与披毛犀化石共存的发现及其意义

云杉孢粉组合与披毛犀,这两类晚更新世的重要化石,过去在天津还没发现和正式报道过。近年来,不但已在天津找到,而且还发现它们同层共存于一个钻孔之中,这种同孔同层共存的事例,在我国还是首次发现,对研究该化石本身及天津当时的地质地理具有重要意义。