生态地质学——地质科学的新分支(英文)

文中介绍了生态地质学的定义 ,探讨其研究客体和研究对象以及岩石圈的生态作用 (指资源生态作用、地球动力学生态作用、地球物理和地球化学生态作用 )。文中还讨论了生态地质学的理论和实践意义 ,并对生态地质学的逻辑构成———科学结构、具体分类进行了详细论述。     

Geochronology and Geochemistry of the Middle Proterozoic Aoyougou Ophiolite in the North Qilian Mountains,Northwestern China

The Aoyougou ophiolite lies in an early Palaeozoic orogenic belt of the western North Qilian Mountains, near the Aoyougou valley in Gansu Province, northwestern China. It consists of serpentinite, a cumulate sequence of gabbro and diorite, pillow and massive lavas, diabase and chert. Ages of 1840±2 Ma, 1783±2 Ma and 1784±2 Ma on three zircons from diabase, indicate an early Middle Proterozoic age. The diabases and basalts show light rare-earth element enrichment and have relatively high TiO2 contents, characteristic of ocean island basalts. All of the lavas have low MgO, Cr, Ni contents and Mg numbers indicating a more evolved character. They are believed to have been derived from a more mafic parental magma by fractionation of olivine, Cr-spinel and minor plagioclase. Based on the lava geochemistry and regional geology, the Aoyougou ophiolite was probably believed to have formed at a spreading centre in a small marginal basin. Subduction of the newly formed oceanic lithosphere in the Middle Proteroz     

Hydrogeological Characteristics of a Karst Mountainous Catchment in the Northwest of Vietnam

This paper presents a preliminary assessment of the hydrogeological characteristics of a karst mountainous catchment, the Suoi Muoi River catchment, in the northwest of Vietnam. The catchment is located at 600 -700 m a.s.l. and covers an area of 284 km. Exposed limestone occupies 32% of the total catchment area. Various types of assessments have been carried out, including geological and hydrogeological field surveys, cave surveys, dye-tracer tests, meteorological and surface water monitoring. Geological studies and cave surveys have identified the most important active cave/conduit systems within the catchment. Although these data are essential, they are insufficient to make a comprehensive appraisal of the hydrologic nature of the catchment under interest. An attempt was made to calculate a global water balance of the catchment, based on short-term (15 months) meteorological and streamflow records. The results show that, despite the existence of a number of substantial cavem conduit systems, the groun     

Baiyun Cave in Naigu Shilin,Yunnan Karst,China

The Baiyun cave is a 380 m long karst cave in the Naigu Shilin, situated 70 km southeast of Kunming, Yunnan Province, China. The prevailing orientations of the cave passages are N110°-120°E and N0°-10°W and those of the fissures in the cave are N30°-40°W and N20°-30°W. The cave is developed in the thick-bedded Lower Permian Qixia Formation. The cave has an active water flow and is currently at the near water-table stage. There are large amounts of different infills of cave sediments. The cave shows different stages of paragenesis. The palaeomagnetic analysis of cave sediments shows that their ages are younger than 780 ka B.P. (the Brunhes Chron). The upper part of the sampled profile belongs to the reverse Blake event (112.3-117.9 ka B.P.). The formation of the Baiyun cave is directly connected with the development of the Naigu Shilin. The formation of karst underground and surface features depends on the regional tectonic deformation and the Cenozoic extension of the study area.     

1995年日本中部伊东市近海震群附近一水井的弱阻尼响应

1995年,日本中部静冈县伊东市近海震群活动期间,我们观测了距震中约5km远的弱阻尼井蓄水层系的同震和非同震水位变化情况。每次水位变化都由随后为阻尼谐振的有线性趋势成分的静位移构成。这些振荡的特征频率和衰减参数分别为18.3s和0.024s~(-1)。震群活动期间,我们在8天内检测到了14次这种事件。位移值几乎都是2 mm或更小,只有两次例外,其位移值分别为4mm和6 mm。观测波形与在弱阻尼蓄水层系中由阶梯状压力水头变化而引起的理论水井水位响应的解析表达式一致。由此一致性,我们可以从观测水文记录中估算出水井蓄水层系的参数和压力水头变化的位移分量。从最近台站的地震记录得出,在14次事件中仅有7次,包括很大位移的2次,明显与震群同时发生。这7次事件中最大的2次已被定量地解释为同震体应变变化的结果。其余5次解释为靠近体应变场节点的同震应变变化的影响,或其他同震的影响。同时,7次未与地震事件同步发生的水位变化也说明了在距井几十米距离内,蓄水层中突发了局部压力扰动。     

晶体大小分布理论与岩浆存储时间的确定—以1959年夏威夷基拉危厄火山喷发物

晶体大小分布理论（CSD理论）的基础为定态粒度平衡，它可用来监测正在沉淀的溶液中生长的特定大小晶体的带出带入量。应用描述该平衡的守恒方程可以直接从晶体大小分布数据中确定晶体生长和成速率。这项研究表明，如果特征的晶体生长速率可以被独立地确定或估计，通过CSD分析可以用计算晶体在体系或火山岩浆中的滞留时间。确定存储时间所需的晶体粒度数据可以从玻璃质喷发样品薄片中很容易的获得，数学计算相对简单。这种新方法固有误差的分析显示存储估计的准确性在一个数量级之内。     

高压下地幔物质的相转变

具有多种压砧装置的高压技术的新进展,使我们能够测定25～27Pa条件下的地幔物质相转变。这样,我们就可以对地幔岩、玄武岩和橄榄岩以及那些与此成分类似的岩石相平衡进行广泛研究(例如,I(?)ifune和Ringwood,1987,a、b)。作者在这里对这些研究及一些新的实验结果作了一些总结,并讨论这些结果对地幔组成和构造的意义。 CaSiO_2-MgSiO_6系统:在使用金刚石压砧所得到的实验结果中,有关透辉石的相转变一直存在着不同意见(如Liu,1987;Tami和Yagi,在出版中)。基于电子探针和扫描电镜对淬火样品中透辉石相转变性质的仔细鉴定,作者的最新研究(I(?)ifune等,在出版中)揭示出,在19GPa以上,透辉石分解成立方晶系的钙钛矿和MgSiO_2组分所     

水文計算的某些簡化

众所周知根据水利經济建設的目标拟定設計时,伴随而来的是要制定水文部分的設計計算,而水文部分設計計算中,大部分又是計算偏差系数。現在我們着手用簡化的方法来进行計算,这种方法节省时間至少为50%,而且它的計算精确度并不減     

X光摄影测量解析法

X 光影象的量测性能已经评论过了.对最重要的系统误差及其影响作了讨论和评价.检定方法已建立起来,也为检定用的控制场作了描述及图解说明.检定所用的数学模型是共线方程式.由于焦点的有限大小,这种数学模型实质上是用近似法求得的.叙述了实验室方法,其目的是为了将 X 光摄影测量解析法所能达到的精度与坐标仪和改装经纬仪直接量测的数据相比较,得到距离残余误差为±0.4mm,旋角为±0.09度.基于这些结果,一种常规操作方法已用于生物——医学方面.