全文获取类型
收费全文 | 159篇 |
免费 | 100篇 |
国内免费 | 34篇 |
专业分类
测绘学 | 3篇 |
地球物理 | 163篇 |
地质学 | 111篇 |
海洋学 | 5篇 |
天文学 | 1篇 |
综合类 | 5篇 |
自然地理 | 5篇 |
出版年
2023年 | 2篇 |
2022年 | 2篇 |
2021年 | 6篇 |
2020年 | 4篇 |
2019年 | 13篇 |
2018年 | 6篇 |
2017年 | 3篇 |
2016年 | 12篇 |
2015年 | 5篇 |
2014年 | 13篇 |
2013年 | 9篇 |
2012年 | 11篇 |
2011年 | 8篇 |
2010年 | 10篇 |
2009年 | 13篇 |
2008年 | 15篇 |
2007年 | 14篇 |
2006年 | 12篇 |
2005年 | 11篇 |
2004年 | 11篇 |
2003年 | 5篇 |
2002年 | 10篇 |
2001年 | 9篇 |
2000年 | 7篇 |
1999年 | 13篇 |
1998年 | 14篇 |
1997年 | 12篇 |
1996年 | 6篇 |
1995年 | 5篇 |
1994年 | 5篇 |
1993年 | 7篇 |
1992年 | 5篇 |
1991年 | 6篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1986年 | 1篇 |
排序方式: 共有293条查询结果,搜索用时 46 毫秒
291.
Nestor Vegas Seta Naba Jean Luc Bouchez Mark Jessell 《International Journal of Earth Sciences》2008,97(6):1165-1180
The Fada N′Gourma area in Burkina Faso is underlain by Paleoproterozoic rocks that make the northeastern West-African Craton.
This region is composed of NE-trending volcano-sedimentary belts and foliated tonalites, affected by several shear zones.
A generation of younger, ∼2100 Ma-old, non-foliated biotite-bearing granites intrudes the former rock units. We have investigated
the younger granite pluton of Kouare that was previously considered as forming a single body with the pluton of Satenga to
the west, a pluton which likely belongs to the ∼20 Ma more recent Tenkodogo-Yamba batholith. Magnetic fabric measurements
have been combined with microstructural observations and the analysis of field and aeromagnetic data. The granite encloses
angular enclaves of the host tonalites. Magmatic microstructures are preserved inside the pluton and solid-state, high-temperature
deformation features are ubiquitous at its periphery. The presence of steeply plunging lineations in the pluton of Kouare
and its adjacent host-rocks suggests that large volumes of granitic magmas became crystallized while they were ascending through
the crust that was softened and steepened close to the contact. Around Kouare, the foliation in the host tonalites conforms
with a map-scale, Z-shaped fold in between NNE-trending shear zones, implying a bulk clockwise rotation of the material contained
in-between the shear zones, including the emplacing pluton. Regionally, the Fada N′Gourma area is concluded to result from
NW-shortening associated with transcurrent shearing and vertical transfer of granitic magmas. This study concludes that the
∼2200 Myears old juvenile crust of Burkina Faso was brittle before the intrusion of the biotite-granites, became softened
close to them and that gravity-driven and regional scale wrench tectonics were active together. 相似文献
292.
Eastern Anatolia consisting of an amalgamation of fragments of oceanic and continental lithosphere is a current active intercontinental contractional zone that is still being squeezed and shortened between the Arabian and Eurasian plates. This collisional and contractional zone is being accompanied by the tectonic escape of most of the Anatolian plate to the west by major strike-slip faulting on the right-lateral North Anatolian Transform Fault Zone (NATFZ) and left-lateral East Anatolian Transform Fault Zone (EATFZ) which meet at Karlıova forming an east-pointing cusp. The present-day crust in the area between the easternmost part of the Anatolian plate and the Arabian Foreland gets thinner from north (ca 44 km) to south (ca 36 km) relative to its eastern (EAHP) and western sides (central Anatolian region). This thinner crustal area is characterized by shallow CPD (12–16 km), very low Pn velocities (< 7.8 km/s) and high Sn attenuation which indicate partially molten to eroded mantle lid or occurrence of asthenospheric mantle beneath the crust. Northernmost margin of the Arabian Foreland in the south of the Bitlis–Pötürge metamorphic gap area is represented by moderate CPD (16–18 km) relative to its eastern and western sides, and low Pn velocities (8 km/s). We infer from the geophysical data that the lithospheric mantle gets thinner towards the Bitlis–Pötürge metamorphic gap area in the northern margin of the Arabian Foreland which has been most probably caused by mechanical removal of the lithospheric mantle during mantle invasion to the north following the slab breakoff beneath the Bitlis–Pötürge Suture Zone. Mantle flow-driven rapid extrusion and counterclockwise rotation of the Anatolian plate gave rise to stretching and hence crustal thinning in the area between the easternmost part of the Anatolian plate and the Arabian Foreland which is currently dominated by wrench tectonics. 相似文献
293.
云南富宁定皇钛铁砂矿矿床成因 总被引:1,自引:0,他引:1
受区域性深大断裂(里达断裂)所控制的海西期—印支期辉长辉绿岩体,是定皇风化壳型钛铁砂矿的含矿母岩.含矿母岩经地表风化、水解作用,再次堆积形成具有工业价值的钛铁砂矿体. 相似文献