铂族元素作为地球化学指示剂有关问题讨论   总被引：1，自引：0，他引：1       下载免费PDF全文

倪善芹侯泉林  琚宜文吴春明刘庆  武昱东 《地质论评》2007,53(5):631-641

铂族元素在研究地球化学过程中发挥着越来越重要的示踪作用。根据铂族元素在不同圈层中的分布,可以探索地球的形成历史和地外撞击事件。根据铂族元素之间的分异性,可用来研究岩浆的部分熔融程度、岩石的形成过程以及大地构造环境的判别等。然而,多年来,由于分析手段和分析方法等的限制,对铂族元素在地质作用过程中的化学行为的认识尚欠深入,对其作为地球化学指示剂的研究还存在诸多问题,许多现象尚不能得到很好的解释。本文提出,应加强地质样品中超痕量铂族元素的高精度分析方法研究和铂族元素在地质作用过程中分异行为、分异规律的研究。  相似文献   

Probabilistic assessment of travel times in groundwater modeling     

J. J. Gómez-Hernández  X. -H. Wen 《Stochastic Hydrology and Hydraulics》1994,8(1):19-55

A Monte Carlo approach is described for the quantification of uncertainty on travel time estimates. A real (non synthetic) and exhaustive data set of natural genesis is used for reference. Using an approach based on binary indicators, constraint interval data are easily accommodated in the modeling process. It is shown how the incorporation of imprecise data can reduce drastically the uncertainty in the estimates. It is also shown that unrealistic results are obtained when a deterministic modeling is carried out using a kriging estimate of the transmissivity field. Problems related with using sequential indicator simulation for the generation of fields incorporating constraint interval data are discussed. The final results consists of 95% probability intervals of arrival times at selected control planes reflecting the original uncertainty on the transmissivity maps.  相似文献   

中国近期自然灾害程度的区域特征^*   总被引：15，自引：3，他引：15  

刘燕华  李钜章 《地理研究》1995,14(3):14-25

本文通过对中国近期灾情的分析,探讨自然灾害区域评价的指标分类和评价指标体系,讨论中国灾情程度的区域特征,文中首先对绝对灾情、相对灾情、绝对灾情变率和相对灾情变率这四项程度进行了分类,随后依单位面积和单位人口与灾情的关系进行了人均灾损、灾损模数、受灾人口模数、受灾面积模数指标的分类。运用上述八项指标,对中国近年灾害程度区域特征进行分析结果表明,中国东部地区灾情最严重,且集中于黄河下游、淮河流域和长江下游区;从历年灾情程度的情况分析结果认为,绝对灾情指标>4.0及相对灾情指标>30%,是目前衡量中国省级灾害承受能力的极限指标。  相似文献   

微细浸染型金矿中As Sb Hg Tl Ba元素的找矿指示意义     

王小春 《矿产与地质》1992,(4):307-312

从As、Sb、Hg、Tl和Ba元素在微细浸染型金矿中的性状出发,探讨了微细浸染型金矿床中指示元素的分带规律及其形成原因,并指出了利用指示元素及其组合对寻找微细浸染型金矿的广阔前景。  相似文献   

Pinus brutia as a biogeochemical medium to detect iron and zinc in soil analysis, chromite deposits of the area Mersin, Turkey     

Zeynep Özdemir 《Chemie der Erde / Geochemistry》2005,65(1):79-88

Soil and pine (Pinus brutia) samples were collected from 64 sites over chromite and ultramafic rocks near Musal?, and over clastic sediments of the Silifke-Anamur areas of Mersin, Turkey. Both sample media were analyzed for their Zn and Fe contents. The results showed similar concentration of both elements in the ash of needles and twigs, with each exhibiting lower concentration than the soils. Zinc was more concentrated in pines from the Silifke-Anamur area than at Musal?, but Fe concentrations were similar in both area. A positive correlation was observed between Zn and Fe in pine and soils (r=0.90 and 0.79, respectively). It is concluded that P. brutia can be used as a biogeochemical sample medium to detect concealed deposits of Zn and Fe.  相似文献   

肖家营子斑岩体地质特征及找矿标志   总被引：4，自引：0，他引：4  

敖颖锋  国铁成  袁国平 《矿产与地质》2001,15(4):233-237

肖家营子斑岩体是由辉长辉绿岩、中粒闪长岩及似斑状细粒闪长岩所组成的复式岩体，岩枝（舌）发育，和同类岩石相比具有富硅、碱和富含Mo,Cu等成矿微量元素的特点，钼金属矿床的形成主要与该斑岩体有关。  相似文献   

环境质量的矿物标识体系研究现状及意义     

贾建业  汤艳杰 《热带地理》2001,21(3):270-275

环境质量的好坏直接关系到人类的生存问题，环境质量评价的科学性是有效治理环境和保护人体健康的前提。天然矿物在形成和变化的整个过程中，不同时间和空间上的环境演变都使矿物的特征发生相应改变，从而成为环境演变信息的载体。对天然矿物的微形貌、微结构、化学组成和成因产状等方面特征与环境关系的研究，可以揭示记录在矿物中的环境演变信息。这是环境矿物学领域中目前较为活跃的研究内容之一。  相似文献   

模糊类别制图的空间统计学方法   总被引：4，自引：1，他引：3  

张景雄  Roger P Kirby 《测绘学报》1998,27(2):166-176

类别地图是地理信息系统（ＧＩＳ）应用中所利用的重要数据类别。这类数据可以从摄影测量和遥感技术得到。用摄影测量方法（影像判读）制作的类别地图常以点、线和多边形的离散目标形式描述,而遥感图像分类方法输出的类别地图以连通光栅块形式表达。不论哪一种情况,在每一个多边形或者光栅块（即制图单元）中仅允许单一类别,边界内部非均匀性和模糊形已经被“过滤”了。这样的类别地图沿用了古曲脆集合论,因为每个制图单元只允许  相似文献   

非均质综合指数法划分储层流动单元   总被引：3，自引：0，他引：3  

李祖兵  罗明高  马斌  刘静 《新疆地质》2005,23(2):203-206

近年来，流动单元概念已被广泛用于储层研究中，取得了较好的效果．但怎样充分利用反映流储层及流动非均质性的各个参数来划分流动单元，目前没有统一的认识，献中多局限在传统的划分方法上．基于充分利用各个反映储层特性的参数的思想，笔提出了非均质综合指数法划分储层流动单元，并用这种方法研究了新疆油田某井区储层流动单元．由实践验证，这是一种比较行之有效的方法，划分的结果是可靠的．  相似文献   

Landscape and a political border determine desert arthropods distribution     

U. Shanas  Y.A. GalyunM. Alshamlih  J. CnaaniD. Guscio  F. KhouryS. Mittler  K. NassarI. Shapira  D. SimonH. Sultan  E. Topel  Y. Ziv 《Journal of Arid Environments》2011,75(3):284-289

We studied the distribution of arthropods in the Arava desert on both sides of the Israeli-Jordanian border, to assess the impact of different anthropogenic pressures on the local fauna. We examined how different landscape units, proximity to agricultural fields, and human societies, might affect the diversity of ground dwelling beetles, and spiders, using ordination and diversity estimation methods. Our results suggest that although both countries contain similar habitats, each has its own unique characteristics, probably due to different cultural practices. The immediate repercussion is that loss of a habitat on one side of the border cannot be compensated with preservation of the same habitat across the border, due to fauna dissimilarity. For example, beetle species can be assembled according to landscape units, but within each landscape unit they show dissimilarities that are based on the geopolitical location. Spiders fail to assemble according to landscape units but cluster as a unique group within Israel. Both landscape unit type and the border, were found to be important for the overall species diversity of this ecosystem and therefore “redundancy” should be carefully applied, especially across geopolitical borders.  相似文献