全文获取类型
收费全文 | 61篇 |
免费 | 18篇 |
国内免费 | 26篇 |
专业分类
测绘学 | 12篇 |
地球物理 | 6篇 |
地质学 | 80篇 |
海洋学 | 2篇 |
综合类 | 3篇 |
自然地理 | 2篇 |
出版年
2024年 | 3篇 |
2023年 | 2篇 |
2022年 | 10篇 |
2021年 | 6篇 |
2020年 | 3篇 |
2019年 | 1篇 |
2018年 | 3篇 |
2016年 | 6篇 |
2015年 | 6篇 |
2014年 | 2篇 |
2013年 | 3篇 |
2011年 | 2篇 |
2010年 | 1篇 |
2008年 | 1篇 |
2007年 | 3篇 |
2006年 | 2篇 |
2004年 | 3篇 |
2003年 | 4篇 |
2002年 | 7篇 |
2001年 | 3篇 |
2000年 | 5篇 |
1998年 | 7篇 |
1997年 | 5篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1994年 | 4篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
排序方式: 共有105条查询结果,搜索用时 0 毫秒
101.
Rui Liu Hanwen Zhou Li Zhang Zengqiu Zhong Wen Zeng Hua Xiang Song Jin Xinqian Lu Chunzhong Li 《Lithos》2010,119(3-4):163-180
U–Pb ages, trace elements, and Hf isotope compositions of zircons from the Mayuan migmatite complex in NW Fujian province have been determined to provide constraints on the source and genesis of anatexis and tectonothermal evolution related to the Caledonian orogeny in South China. The migmatites investigated consist of various amounts of mesosome, leucosome, and melansome. Zircons extracted from mesosome, leucosome, and granite samples are characterized by oscillatory overgrowths enclosing inherited cores or occur as newly grown grains. The ages of the inherited zircons from the leucosome and granite samples are consistent with those of adjacent basement paragneiss in the study area, suggesting that both leucosome and granite were generated by partial melting of the latter. A comparison of Hf isotopes between the newly-formed zircons and inherited cores indicates that the former resulted from the breakdown of preexisting inherited zircons and/or less Hf-rich minerals other than zircons at the source. One mesosome sample contains typical metamorphic zircons that yielded a weighted mean 206Pb/238U age of 453 ± 3 Ma. They show enrichments in heavy REEs (LuN/LaN up to 22,709), indicating their growth prior to garnet crystallization. The other mesosome sample, in contrast, contains both newly-formed metamorphic rims and grains that gave a weighted mean 206Pb/238U age of 442 ± 8 Ma. They are characterized by relatively low Th/U ratios, depletions in heavy REEs (LuN/LaN = 117–396), and low 176Lu/177Hf ratios, suggesting their growth synchronous with garnet crystallization. The U–Pb ages of the mesosome samples are interpreted as recording the time of early (ca. 453 Ma) to peak (442 Ma) stages of a regional metamorphic event. Two leucosome and two granite samples yield consistent U–Pb ages of 438 ± 5 Ma to 442 ± 4 Ma, which provide constraints on the timing of subsequent anatexis and magmatism. The geochronological data reported here reveal a consecutive sequence of regional metamorphism, anatexis, and magmatism in NW Fujian province, lasting for at least 15 Myr, which was driven by the Caledonian orogeny that have affected a major part of the SCB. 相似文献
102.
103.
蓝家庄金矿床位于牟平-乳山金成矿带南部,为一处严格受构造控制的蚀变岩型为主石英脉型次之的大型金矿床。控矿构造内煌斑岩的大量出现,显示控矿构造具有贯通下地壳的特点,可以为幔源含矿岩浆流体浅部就位提供空间条件。研究认为矿化蚀变带中心发育的正长斑岩与金成矿关系密切;矿床地质特征和穿插关系显示矿床形成经历了4个热液成矿期,第Ⅱ和第Ⅲ成矿阶段(石英-黄铁矿和石英多金属硫化物阶段)为主要的金成矿期,矿物组合特征显示应属浅成低温热液矿床;矿床深部可能发育的超壳断裂和斑岩体,为研究胶东金矿矿床成因提供了新视角。 相似文献
104.
豫西双龙韧性剪切带是位于秦岭造山带核部的一条韧性剪切带,由两侧到中心依次发育了初糜棱岩、糜棱岩、超糜棱岩及假玄武玻璃一系列动力变质岩。该韧性剪切带是东秦岭造山带核部网结状走滑韧性剪切带中的一条,对其开展显微构造研究,对了解东秦岭造山带的变质变形环境及构造演化具有一定地质意义。本文在野外地质工作的基础上,通过对韧性剪切带进行岩石学和矿物显微构造特征分析,对韧性剪切带的性质及温度、古差应力、应变速率等变质变形环境进行了分析讨论。研究表明,双龙韧性剪切带运动学性质为左行剪切,变质变形温度约为400~500℃,古差应值约为51~61MPa。 相似文献