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311.
312.
基于GIS的水资源管理信息系统 总被引:22,自引:0,他引:22
地理信息系统(GIS)因为其强大的空间数据处理能力,为水资源管理提供了一个新颖、高效的工具。本文深入GIS的功能和水资源管理的实际,通过山西汾阳县的应用实例,阐述了应用ArchInfo/ArcView构建水资源管理信息系统过程中的信息收集、储存、分析以及二次开发的方法和过程,分析了两者结合应用的可行性和优越性,并讨论了这种方法在水资源系统模拟、辅助决策支持等方面的广泛应用前景。 相似文献
313.
Robert A. Langel 《Journal of Earth System Science》1990,99(4):581-618
Among the first measurements made from near-Earth orbiting satellites were measurements of the magnetic field. The sources
of that field lie both within the Earth, in its core and crust, and in the surrounding ionosphere and magnetosphere. This
article summarizes some of the methodology and results for studies of the Earth’s mantle and crust. Mantle conductivity studies
can be made either by studying signals impressed on the Earth from outside, e.g., the ionosphere or magnetosphere, or by studying
signals originating in the core and transmitted through the mantle. Crustal field studies begin with a careful selection of
the data and subsequent removal of core and external fields by some sort of filtering. Average maps from different local times
sometimes differ, presumably due to the remaining presence of fields of external origin. Several techniques for further filtering
are discussed. Where large-area aeromagnetic maps are available, crustal maps derived from satellite data can be compared
with upward continued data. In general, the comparisons show agreement, with some differences, particularly in and near the
auroral belts. The satellite data are further reduced by various methods of inverse and forward modelling, sometimes including
reduction to the pole (RTP). These techniques are generally unstable at the equator. Common methods of stabilizing the inversions
include principle components analysis and ridge regression. Because of the presence of the core field, the entire crustal
contribution from the field is not known. Also, there is a basic nonuniqueness to the inverse solutions. Nevertheless, magnetizations
that are interpretable can be derived. 相似文献
314.
Quantitative pyrolysis-gas chromatography has been performed on 96 kerogen samples isolated from 17 wells on the Norwegian Continental shelf. Petrographic and bulk geochemical measurements were also performed on the samples, and a combined data set of 117 variables for each sample was analysed using principal components analysis (PCA). This approach provides an objective and reproducible means of kerogen characterisation, which can be easily automated. In addition to objective kerogen characterisation and facile visualisation of facies and maturity related chemical trends, the method has the potential to allow objective prediction of key geochemical parameters such as maturity level from pyrogram data. 相似文献
315.
316.
自20世纪90年代末以来,在有关国家专项的支持下,中国先后研制了分别取自黄海、东海和南海的共9个大陆架沉积物地球化学标准物质,基本构成了一个比较有代表性的中国海及大陆架沉积物标准物质系列,为中国海洋国土及专属经济区调查研究工作提供了有力技术支撑.本文简介了这些标准的研制背景、概况,着重评介了这些标准物质的特点,特别说明了该标准物质系列在海洋地质调查与研究中应用及在地质分析技术发展上的意义. 相似文献
317.
扎河坝蛇绿混杂岩内富铌玄武(安山)岩的地球化学特征及其地质意义 总被引:1,自引:2,他引:1
在新疆北部东准噶尔的扎河坝蛇绿混杂岩中发现的富铌玄武(安山)岩,其SiO2含量介于46.71%~57.65%,TiO2含量为1.00%~1.76%,与太古代绿岩带内富铌玄武(安山)岩相似,Na2O含量为3.86%~6.64%,P2O5为0.34%~0.82%,明显高于太古代绿岩带富铌玄武(安山)岩。扎河坝富铌玄武岩铌含量介于7.22×10-6~21.91×10-6之间,大于7×10-6,与典型的富铌玄武岩相同。该岩石轻重稀土元素分馏较明显,其分布模式为无明显铕至弱负铕异常的右倾曲线。尽管铌的绝对含量较高,但由于钍和轻稀土元素更加富集,在微量元素蛛网图中扎河坝富铌玄武(安山)岩仍表现为铌的明显亏损,同时高场强元素Zr、Hf及Ti也表现出一定程度的亏损。微量元素地球化学特征显示,扎河坝蛇绿混杂岩内富铌玄武(安山)岩形成于古亚洲洋的洋内弧,它是被埃达克质岩浆交代的地幔楔橄榄岩部分熔融的产物,同时大洋沉积物及俯冲板块释放的流体对成岩作用也有一定的贡献。富铌玄武(安山)岩作为弧前增生楔定位在扎河坝蛇绿混杂岩体内,与早前报道的超高压变质岩共存表明,该蛇绿混杂岩体至少记录了两次性质不同的古亚洲洋洋壳俯冲,这更进一步证实新疆北部晚古生代新增陆壳是古亚洲洋多次俯冲作用的产物。 相似文献
318.
大地构造学是现今地质学研究的热门学科,大陆裂谷构造属于大地构造的研究范畴。本文从裂谷沉积作用与成矿的简单联系和由于先存下地壳组构对大陆裂谷构造的影响两方面介绍了国外对大陆裂谷研究的情况。作者指出:大地构造学的研究需借助假定的模式或实验模型,但不能局限于其中;大地构造学的各个研究领域都存在着挑战,地质学的研究需要进一步完善。 相似文献
319.
Massive Sulphide Deposits Related to the Volcano-Passive Continental Margin in the Altay Region 总被引:3,自引:0,他引:3
WANG Jingbin DENG Jiniu ZHANG Jinhong QIN KezhangBeijing Institute of Geology for Mineral Resources State Bureauof Nonferrous Metal Industry Andingmenwai Beijing Zhu Xiling 《《地质学报》英文版》1999,73(3):253-263
The Devonian volcano-passive continental margin in southern Altay is a significant volcanogenic massive sulphide metallogenic belt. Acidic volcanism has been dominant on the inner side of the volcano-passive continental margin, i.e., near the old land, resulting in a Pb-Zn metallogenic sub-belt, in which the ore deposits are hosted by sedimentary rocks in volcanic series, as represented by the large Koktal Pb-Zn deposits. In the central part of the margin far away from the old land, bimodal volcanic formations are well developed, forming volcanics-hosted Cu-Zn metallogenic sub-belts, e.g., the large-scale Ashele Cu-Zn deposit. The Qiaoxiahala sub-belt on the outer side of the margin near the ocean ridge is located at the spreading central trough, where ophiolite suites are developed. This type of deposits is rich in gold and copper, similar to the Cyprus-type Fe-Cu-Au metallogenic sub-belt in metallogenic environment (represented by the Qiaoxiahala medium-scale Fe-Cu-Au deposit). From the old land to th 相似文献
320.
Magmatic activity and its geological significance in Early Jurassic in Mangui area of Inner Mongolia
By investigating the U-Pb zircon isotope geochronology and petrogochemistry of the major magmatic rocks in Mangui area, the authors in this paper discussed the forming era, tectonic background and geological significance. A large amount of intrusive rocks and a small amount of medium-acid volcanic rocks in Early Jurassic were found in this area. U-Pb dating by LA-ICP-MS method shows that the ages are from (199±1)Ma to (184±1)Ma and the rock types can be divided into fine-medium-grained quartz diorite, medium-grained granodiorite, fine-medium-grained monzogranite, medium-fine-grained macrophenocryst monzogranite, rhyolite, dacite and andesite, which didn’t ouur in Neoprotezoic-Paleozoic period as previous researchers thought, revealing the tectonic and magmatic activities during the Early Mesozoic period. The geochemical results show that the rocks are Ⅰ-type magmatic rocks of subluminous-peraluminous high-K calc-alkaline series. The fractionation between light and heavy rare-erath elements((La/Yb)N= 3.42~32.96) and the Eu depletion degree is not complied with the evaluation from basic to acidic. The large ion lithophile element Ba is relatively rich and Rb, Sr are relatively delicient. The high field strength elements Th and U are relatively rich and Nb, Ti, Y are relatively deficient. The magma origin and tectonic setting show that quartz diorite and medium-fine-grained macrophenocryst monzogranite come from crust-mantle mixed magma, while the medium-acid volcanic rocks, granodiorite and fine-medium-grained monzogranite are from the partial melting of crustal materials, whose formation is connected with the evolution of Mongol-Okhotsk Suture Zone. The geology and geochemistry of the Early Mesozoic magmatic rocks indicate that the middle part of Mongol-Okhotsk Ocean might begin subduction at the end of the middle Triassic and close the Early Jurassic. The peak collision might take place at the Early Jurassic, not in the Late Triassic as previous thought. The Mohe over-thrust nappe system might form in the remote effect of southward extrusion during the closing process of the eastem part of Mongol-Okhotsk Ocean. The middle and eastern Mongol-Okhotsk Ocean closing age is of great importance to reveal the basin-range tectonic formation during the Middle Jurassic to the Late Cretaceous in Northeast China. 相似文献