共查询到19条相似文献，搜索用时 140 毫秒
1.
In common with most of the larger ophiolite bodies that were emplaced during the Cenozoic and late Mesozoic and which have experienced relatively little post-emplacement disruption or metamorphism, the Zambales Ophiolite Complex (ZOC) of western Luzon (northern Philippines) is associated with very large gravity anomalies. Worldwide and in the ZOC, peak to trough amplitudes of more than 100 mGal are common and amplitudes in excess of 200 mGal are not unknown 相似文献
2.
3.
光谱矿物定量方法的基本原理 总被引：2，自引：0，他引：2
On account of the natural distribution of the mineral grains in the specimen under preparation, a new emission-spectrographic method has been developed on the basis of the principles of the permutations and combination of mineral grains, which are deduced from theoretical calculation and experimental tests. This method has been proved valid and applicable to the investigation of .the mode of occurrence of rare elements and to the quantitative determination of minerals as well as to the performance of statistics of their grain -size distribution in geologic samples. 相似文献
4.
WANG Weifeng JIN Qiang Department of Resources University of Petroleum Dongying Shandong MA Zongjin Institute of Geology Seismological Bureau of Chin Qijiahuozi Beijing Zhu Xiling 《《地质学报》英文版》1998,72(4):350-362
There are a group of large and medium-scale Meso-Cenozoic petroliferous basins along both sides of the Tanlu fault or within the fault zone, e.g., the Songliao basin, the Bohai Bay basin and the Subei-Yellow Sea basin. As shown by studies of the structural types, sedimentary formations, volcanic activities, tectonic evolution as well as the time-space relationship between the Tanlu fault zone and the basins, the formation and distribution of the basins are controlled by the movement of the Tanlu fault. This paper presents an analysis of the tectono-geometric, kinematic and geodynamic features of the basins on the basis of integrated geological-geophysical data, and an exploration into the internal relations between the fault and the basins as well as the formation mechanism and geodynamic processes of the basins. 相似文献
5.
Helmut TISCHLINGER 《地球学报》2010,31(Z1):62-63
The first discoveries of pterosaur fossils were made at the end of the 18th century and during the first decades of the 19th century in Bavaria, southern Germany. They originate from limestone quarries in the vicinity of the village of Solnhofen and adjacent hamlets as well as from limestone pits close to the town of Eichst?tt. 相似文献
6.
A new macrofossil Lagerstatte was discovered from the uppermost Ediacaran Jiucheng Member at Jinning and Jiangchuan of the eastern Yunnan, yielding numerous diverse well-preserved thallophyte macrofossils. These include the previously-known representatives of vendobionts, Vendotaenia and Tyrasotaenia, and the biggish multicellular benthos such as Chuaria-like and Tawuia- like fossiis, as well as Longfengshaniaceaens with diverse holdfast structures. There are still some other problematic macrofossils with peculiar configurations as well as uncertain relatives. The distinct dominance of the giant, unbranching thallophytes occasionally with holdfast structures distinguishes this assemblage from the other Ediacaran macrofossil Lagerstattes in the Doushantuo Formation at Miaohe, Wenghui and Lantian, and the contemporary assemblage in the Shibantan Member of Dengying Formation, Yangtze Gorges area. This paper outlines the characteristics of some of the multicellular macrofossils from the Jiucheng Member at Jiangchuan. They include some macrofossils with different types of holdfast structure, larger Chuaria-like and Tawuia-like morphology and questionable affinities as well. The discovery of greater diverse macrofossil assemblages from the Jiucheng Member of eastern Yunnan has further indicated that an important diversification and evolutionary radiation of metaphytes took place in the latest Ediacaran time. This radiation of largescale, benthic metaphyte along with phytoplankton was likely important contributors to the early Cambrian explosion of metazoans. 相似文献
7.
The origin and history of the Earth are manifested as the evolutionary processes of chemistry and physics of its interiors,which can be recognized by deciphering the geochemical signals recorded in minerals and rocks.Deep interiors of the Earth and other rocky planets are under both extreme pressure and temperature,i.e.,approximately 360 gigapascals(GPa)and as high as 7000 K at the center of the Earth. 相似文献
8.
The occurrences of the Viviparid shells in palaeontic state as well as inrecent form are recorded as abundant from various districts of Yunnan as far asthe old records show.During the later half of the last century,Neumayr,Nevill,Anderson,Mabille,Heude,etc.,the more recently,Dautzenberg,H. 相似文献
9.
Deformation Field around the Stress Induced Crack Area in Sandstone by the Digital Speckle Correlation Method 总被引：1，自引：0，他引：1
Abstract: The deformation field around sub-cracks was calculated using the digital speckle correlation method. First, the uni-axial compression tests on sandstone samples containing a pre-fabricated fracture were made. Photomicrographs showing the characteristics of the sub-crack development were taken using a scanning electron microscope (SEM). From these photomicrographs, the real-time images showing the initiation, growth and coalescence of sub-cracks and micro-cracks in the sandstone specimens were obtained and the effects of loading level as well as grain boundaries on the development of cracks were analyzed. Second, the intensity images of the sandstone specimen surface were captured from the observations of the SEM corresponding to different loading levels. Then correlation computation was carried out for the sequential pairs of intensity images to evaluate the displacement components, as well as the strain field. The results show that the deformation varies in different areas separated by sub-cracks during rock damage processes. 相似文献
10.
LI Qiugen CHEN Xu LIU Shuwen WANG Zongqi ZHOU Yingkui ZHANG Jian WANG Tao 《《地质学报》英文版》2009,83(3):550-561
Abstract：In this study, whole-rock geochemical and Nd isotopic data, as well as detrital zircon Hf isotopes of Palaeoproterozoic metasedimentary rocks from the Jiangxian Group are presented to evaluate the characteristics of their provenance and the tectonic history. The major and trace element compositions are comparable to Post-Archean upper continental crust (PA-UCC), but have slight enrichment in the LILE, with the exception of Cs and Sr, and a slight depletion in ferromagnesian elements, HFS elements, such as Nb and Ta, and some major elements, such as CaO and Na2O. The geochemical data reveal that the collected metasedimentary rocks have experienced intermediate source weathering with chemical index of alteration values ranging from 72 to 78, varying degrees of K-metasomatism, and post-depositional loss of Na, as well as negligible sorting, and are derived from the weathering of mostly felsic and non-mafic rocks. The selected Lu–Hf isotopic analysis on detrital zircon points to both the Trans-North China Orogen and Eastern Block of the north China craton as the most likely sources for the metasedimentary rocks of the Jiangxian Group. However, a contribution of detritus from the Western Block of the north China craton can be ruled out. The sediments were probably deposited in a back-arc basin within an active continental margin setting. 相似文献
11.
《水经注》中有关北京地理的科学思想 总被引：1，自引：0，他引：1
《水经注》是我国古代著名的地理学著作之一,作者郦道元是北魏时期范阳(涿州—北京)人,因此书中对北京附近的水系和地理情况进行了描述。书中称拒马河为巨马水、大石河为圣水、永定河为漯水、清水河为清夷水、温榆河为湿馀水、潮白河为鲍邱水、泃河为泃水,称永定河出山段为清泉河、流经北京城内的什刹海和中南海为高粱河。对家乡附近的地理进行了描述,称房山为大房岭、石景山为梁山,记录了昌平县、密云戍、平谷县等行政区域,记录了羊头埠(羊头岗)、马兰(马栏)、芹城(秦城)、独乐水(独乐河)、良乡、居庸关、盘山等地名。记录了中国最早的首都——涿鹿,记录了中国现代首都蓟城(北京)内曾有蓟丘,说明永定河沟通了古今首都。记录了北京最早的水利工程戾陵堰和车箱渠。 相似文献
12.
从战略目标、主业定位、理顺事企关系的思路和途径、组织架构、管理制度等方面简述了“江南模式”的主要内容,分析了“江南模式”的特点,即具有实践性又有理论性,既有特殊性又有普适性,既有现实性又有动态性,指出“江南模式”的推行对于广东煤炭地质局的改革和发展,对于地勘单位加强战略研究和主业定位,理顺事企关系,提升管理水平有一定的参考价值。 相似文献
13.
激光剥蚀-电感耦合等离子体质谱准确测定锆石中钛的含量 总被引：2，自引：2，他引：0
外标物质及内标元素的选择是激光剥蚀-电感耦合等离子体质谱(LA-ICP-MS)准确测定元素含量的关键因素之一。文章选用玻璃标准参考物质NIST 610、GSE-1G、BHVO-2G、BCR-2G、ATHO-G、KL2-G和T1-G作为外标,Si或Zr作为内标,对锆石M257中的Ti进行LA-ICP-MS微区原位测定。结果显示,选择Si或Zr作内标,采用BCR-2G、ATHO-G、KL2-G和T1-G作外标时,Ti含量测定值与参考值之间差异均较大,因此它们不适合作外标物质。采用BHVO-2G作外标和Si作内标,NIST 610作外标和Zr作内标,Ti含量测定值与参考值之间的差异均小于4%,因此BHVO-2G和NIST 610可有条件地作为外标物质。选择Si还是Zr作内标,GSE-1G作外标时,Ti含量的测定值与参考值之间的差异均小于3%,说明GSE-1G是较为合适的外标物质。选用GSE-1G作为外标,Si作内标,对5个标准锆石中的Ti含量进行了测定,结果显示,Ti元素在锆石91500中分布不均匀,而在锆石GJ-1、M257、PENGLAI和MUDTANK中分布均匀。在Ti元素分布均匀的GJ-1、M257、PENGLAI和MUDTANK等4个锆石中,由于Ti的含量均小于5μg/g,不适合作为锆石中Ti元素测定用的外标物质,但可作为测定时的质量监控样品。 相似文献
14.
滇池流域石漠化特征分析 总被引：2，自引：2，他引：0
位于云南省会昆明盆地内的滇池流域是滇中岩溶和石漠化较为发育的地区,石漠化总面积225.56 km2,占流域总面积的7.71%,占岩溶总面积32.69%。石漠化主要分布在望海山、大板桥—呈贡、黑林铺、海口、梁王山、上蒜片区,其中又以北东部的大板桥片区石漠化最为严重。石漠化已造成流域内水土流失加剧、可耕地面积减少、土壤涵养水源能力降低及生态环境恶化等危害。通过地面调查和ETM遥感解译,查清了流域内石漠化的发育分布与碳酸盐岩的岩性及其组合、岩溶作用、地形地貌、气象等自然因素、人为因素和工业污染关系密切。针对石漠化的形成原因,提出了生态修复、农田基本建设、水资源开发利用、农村能源建设、小集镇建设、土地合理利用等治理措施。 相似文献
15.
Lü Delin 《中国地质大学学报(英文版)》2001,12(4)
Since Dow (l972) proposed the concept of oil system atthe AAPG annual meeting in l972, after unremitting effol.tsand progressive perfection, it has become the petroleum systemaccepted by numerous geologists at present. The concept of pe-troleum system was introduced to our country in early l990s(I)ou, l999). In fact, as early as the 1960s, based on the hy-drocarbon exploration and development practice at Songliao ba-sin and Bohai Bay basin, some viewpoints similar to petroleumsystem have be… 相似文献
16.
17.
18.
本文简述地震前兆观测场的要求 ,福建数字地震前兆台网在依据观测场的要求是如何合理分布各观测点。并着重阐述了数字地震前兆台网仪器观测技术系统的组成 ,前兆台网仪器安装过程及仪器安装过程需注意的事项。对福建数字地震前兆台网的安装做了小结。对此次仪器安装过程所遇到的问题如何合理摆放仪器、规范综合布线、传感器密封、避雷地线等做了几点建议。笔者结合多年的维修实际操作经验 ,对地震前兆仪器的设计如何提高仪器标准化、集成化、为维修的方便提出几点思考建议。 相似文献
19.
Concentrations of contaminants in surface water samples collected in west-central Indiana impacted by acidic mine drainage 总被引：1，自引：0，他引：1
The results of analyses of surface waters collected from a variety of locations in west-central Indiana indicate extensive contamination by acidic mine drainage. These samples had pH values as low as 2.1 and total iron concentrations as high as 1200 mg1–1. The speciation of iron, expressed as the ratio [Fe(II)]/[Fe(III)] ranged from 0.08 to 8.27. Measured lead concentrations were as high as 811 mgl–1. In addition, the concentrations of nitrate and sulfate ions were as high as 359 and 624 mgl–1, respectively. 相似文献