全文获取类型
收费全文 | 78篇 |
免费 | 11篇 |
国内免费 | 36篇 |
专业分类
地球物理 | 12篇 |
地质学 | 111篇 |
综合类 | 1篇 |
自然地理 | 1篇 |
出版年
2023年 | 2篇 |
2022年 | 1篇 |
2021年 | 4篇 |
2019年 | 5篇 |
2018年 | 3篇 |
2017年 | 2篇 |
2016年 | 2篇 |
2015年 | 4篇 |
2014年 | 3篇 |
2013年 | 8篇 |
2012年 | 7篇 |
2011年 | 5篇 |
2010年 | 4篇 |
2009年 | 6篇 |
2008年 | 6篇 |
2007年 | 9篇 |
2006年 | 3篇 |
2005年 | 4篇 |
2004年 | 5篇 |
2003年 | 3篇 |
2002年 | 2篇 |
2001年 | 5篇 |
2000年 | 6篇 |
1999年 | 2篇 |
1998年 | 7篇 |
1997年 | 2篇 |
1996年 | 7篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1989年 | 1篇 |
1980年 | 1篇 |
排序方式: 共有125条查询结果,搜索用时 31 毫秒
31.
32.
Lúcia T. da Rosa-Costa Jean-Michel Lafon Alain Cocherie Claude Delor 《Journal of South American Earth Sciences》2008,26(4):445-462
The Amapá Block, southeastern Guiana Shield, represents an Archean block involved in a large Paleoproterozoic belt, with evolution related to the Transamazonian orogenic cycle (2.26 to 1.95 Ga). High spatial resolution dating using an electron-probe microanalyzer (EPMA) was employed to obtain U–Th–Pb chemical ages in monazite of seven rock samples of the Archean basement from that tectonic block, which underwent granulite- and amphibolite-facies metamorphism. Pb–Pb zircon dating was also performed on one sample.Monazite and zircon ages demonstrate that the metamorphic overprinting of the Archean basement occurred during the Transamazonian orogenesis, and two main tectono-thermal events were recorded. The first one is revealed by monazite ages of 2096 ± 6, 2093 ± 8, 2088 ± 8, 2087 ± 3 and 2086 ± 8 Ma, and by the zircon age of 2091 ± 5 Ma, obtained in granulitic rocks. These concordant ages provided a reliable estimate of the time of the granulite-facies metamorphism in the southwest of the Amapá Block and, coupled with petro-structural data, suggest that it was contemporaneous to the development of a thrusting system associated to the collisional stage of the Transamazonian orogenesis, at about 2.10–2.08 Ga.The later event, under amphibolite-facies conditions, is recorded by monazite ages of 2056 ± 7 and 2038 ± 6 Ma, and is consistent with a post-collisional stage, marked by granite emplacement and coeval migmatization of the Archean basement along strike-slip shear zones. 相似文献
33.
Gold Headquarter of the CAPF has discovered the Yangshan super large-scale gold deposit in Gansu Province, which is a great breakthrough of gold exploration and prospecting in Western Qinling Mountains of China. The gold resources of this deposit achieved 308 tons with increasing potentials. Preliminary geological investigations indicate that the Yangshan gold deposit is located in the intra-continental collision orogenic belt; and the deposit was formed during the continent-continent collision orogenic processes. The geological characteristics of the deposit are similar to that of the typical Carlin-type gold deposits, while differences still exist. The ore-forming background is notably different from the Carlin gold deposit province in the United States; and the ore-forming fluids are similar with that of the orogenic-type gold deposit. Accordingly, the Yangshan gold deposit is a transitional type between the Carlin-type and the orogenic type gold deposits. At present, the Yangshan gold deposit is the largest Carlin and Carlin-like type gold deposit that is ever discovered in China. Researches on metallogeny, metallogenic model and ore-enrichment regularities of the Yangshan gold deposit are crucial to meet the pressing needs of the current geological investigation and ore exploration of the deposit. 相似文献
34.
哀牢山造山型金成矿系统:复合造山构造演化与成矿作用初探 总被引:55,自引:49,他引:6
哀牢山金矿带是我国最重要的喜马拉雅期造山型金矿带,形成于三江特提斯复合造山过程中。论文基于对哀牢山复合造山带区域构造背景、控矿构造系统演化、金成矿期次及其时代的系统研究,从金成矿年代序列、成矿过程构造控制及成矿作用动力学环境三个方面,探讨了复合造山过程中的金矿成矿作用。研究结果表明,哀牢山金矿带发育三期金矿成矿-热事件:早期金成矿作用(61.55~63.09Ma)对应于逆冲推覆构造系统最为发育的时期,与剪切走滑断裂构造的形成同步,显示它们统一受控于印度-亚洲大陆碰撞早期的强烈汇聚挤压构造动力学体制;主期金成矿作用(33.76~36.10Ma)对应于区域挤压构造应力场的相对松弛阶段以及富碱斑岩和剪切走滑断裂构造系统最为发育的时期,受控于印度-亚洲大陆碰撞构造动力学转换体制,并可能受青藏高原物质东向逃逸和软流圈脉动隆起的联合制约,金矿大规模成矿作用与构造动力体制转换过程中的壳幔物质强烈交换与构造变形密切相关;晚期金成矿作用(26.40~30.80Ma)对应于岩石圈伸展作用的发生以及亏损地幔减压熔融产生的板内高钾岩浆岩的就位,受控于印度板块反向旋转拖曳与斜向俯冲回退的综合作用。 相似文献
35.
Mesozoic fill-sequences in Hefei Basin: Implication for Dabie Orogenesis, central China 总被引:2,自引:0,他引:2
A research on the Mesozoic fill-sequences of Hefei basin, located at the north foot of Dabie Mountains, shows two-phase evolution.
The first phase, early- to mid-/late-Jurassic, is characterized by terrestrial clastic deposits, with four times of reverse-grading
units at least, and forms greatly thick molass reconstruction in the mid-/late-phase, which reflects gradually strong thrusting-orogenesis
in the north Dabie and flexural depression in the north foreland of Dabie Mountains. The second phase, late-Jurassic to Cretaceous,
includes two-episode rifting processes. The first episode (J3) shows calc-alkalic and alkali volcanic rocks interstratified pyroclastic rocks, which may reflect upwelling igneous magma
from mantle-source due to the Yangtze continent slab breakoff induced by deep subduction process. A suite of lacustrine, fluvial
and piemount facies, about 3000 –3500 m in thickness, develops in the second episode (J3-K1), which reflects regional extensional setting and intense elevator diversity of mountain-basin in the study area. This research
renews and deepens cognition for the Mesozoic Dabie orogenesis 相似文献
36.
After accretion of the Pampean continental fragment to the western Rio de la Plata craton margin (530 Ma), subsequent deformation, crustal anatexis and plutonism may have been intraplate responses to Brasiliano-PanAfrican collisional tectonism on the eastern margin during the amalgamation of Gondwana. Investigations of intraplate orogens such as the Tien Shan and the Ancestral Rocky Mountains, as well as of analogue and numerical models, permit discrimination of two early Paleozoic tectonomagmatic phases in the Sierras Pampeanas. The first involved marginal trough subduction and calc-alkaline magmatism, culminating in accretion of the Pampean terrane to the western craton edge; the second was characterized by crustal anatexis and peraluminous plutonism, penetrative deformation and high-angle reverse faulting resulting from continental collision on the eastern craton margin.Field observations from modern (Tien Shan) and ancient (Ancestral Rocky Mountains) intraplate chains, deep seismic and borehole data, radiometric and fission-track data constitute control for analogue and numerical models of intraplate deformation resulting from continental collision. Near-simultaneous continent-wide deformation, regularly spaced ranges/buckles, reverse-fault initiation at fold hinges of buckles, and doubling of crustal thickness are replicated in structural arrays formed in four-layer analogue models of lithospheric buckling. These data have significant implications for the ductile deformation, crustral thickening and post-subduction plutonism that spanned central South America in Late Cambrian time. 相似文献
37.
Metallogenic geodynamic background of Mesozoic gold deposits in granite-greenstone terrains of North China Craton 总被引:4,自引:0,他引:4
The spatial distribution map of 65 mid-large gold-deposits hosted in the granite-greenstone terrains of the North China Craton
is first drawn. These gold deposits mainly concentrate in the Mesozoic remobilized Yinshan-Yan-shan-Liaoning-Jilin intracontinental
collisional orogenic belt, the northern Qinling and the Jiaodong Mesozoic collisional orogenic belts, and the Mesozoic intracontinental
fault-magmatic belts developed along the Taihangshan and the Tan-Lu faults; their mineralizing time is predominantly Jurassic-Cretaceous,
i. e. the Yanshanian. The metallogenic geodynamic background is exactly the compression-to-extension transition regime during
continental collision.
The results are partly from the project entitled “The main types of gold mineralizations in China and their metallogenic model”
(89-El) supported by the Ministry of Metallurgical Industry of China, and projects “Geology and metallogenesis of the main
type gold deposits in East Chinan” (Grant No. 9488010) and “Study on ore-forming fluids of the Wangfeng gold deposit, Xinjiang” supported by the National Natural
Science Foundation of China (Grant No. 49672119). 相似文献
38.
39.
多岛海型造山作用——以华南印支期造山带为例 总被引:24,自引:1,他引:23
大陆造山带大多数形成于弧弧碰撞及其弧后盆地衰缩作用,其古地理格局为多岛海。今日的东南亚是多岛海大地构造的现实模型,其中欧亚大陆和澳大利亚的板块边界位于印度尼西亚的班达—巽它弧以南和西太平洋马里亚纳弧以东。介于前缘弧和欧亚大陆之间的是众多的残余弧和弧后盆地。其中有些盆地仍然是海底扩张的中心,一些是不再活动的海盆,也有些海盆正在遭受挤压作用,而一些海盆则已经完全被弧后衰缩作用所消减。位于这些盆地之间的是残余弧,沉降的残余弧顶部的沉积层序类似于被动陆缘。华南大地构造可用多岛海模式予以解释。华南造山带的大地构造相分析、沉积相分析和古地磁等综合研究结果表明,它们大多数是弧弧碰撞作用所形成的碰撞型造山带,二叠—三叠纪的古地理存在着与东南亚今天类似的多岛海格局。临沧弧和华夏弧可能为华南多岛海的前缘弧,起着与今天欧亚大陆的印度尼西亚弧相类似的作用。多岛海古地理格局可能出现于泥盆纪以后,华南板块发生裂解,所形成的弧后盆地大多数于晚三叠世到早侏罗世发生衰缩。 相似文献
40.
The Junggar orogen, Xinjiang, China, is an important part of the Ural-Mongolian orogen.The collisional orogenesis in this region occurred primarily in the Carboniferous and Permianwith an evolutional process of early compression and late extension. Mineralization of gold andother metals in the Junggar orogen occurred mainly in the Permian and in a few cases in theLate Carboniferous. The deposits are largely distributed in areas where collisional orogenesiswas intensive and formed in a transitional stage from compression to extension. Therefore, goldmineralization in the Junggar orogen is fully consistent with the collisional orogenesis in time,space and geodynamic setting. This indicates that the mineral deposit model of collisionalorogenesis is applicable to prospecting and study of ore deposits in the Junggar orogen.Furthermore, the factual distribution of gold and other deposits in this region is just the same asthe collisional orogenic model presents. 相似文献