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The Late Cretaceous ükapili Granitoid including mafic microgranular enclaves intruded into metapelitic and metabasic rocks, and overlain unconformably by Neogene ignimbrites in the Ni de area of Turkey. It is mostly granite and minor granodiorite in composition, whereas its enclaves are dominantly gabbro with a few diorites in composition. The ükapili Granitoid is composed mainly of quartz, K-feldspar, plagioclase, biotite, muscovite and minor amphibole while its enclaves contain mostly plagioclase, amphibole, minor pyroxene and biotite. The ükapili Granitoid has calcalkaline and peraluminous (A/CNK= 1.0-1.3) geochemical characteristics. It is characterized by high LILE/HFSE and LREE/HREE ratios ((La/Lu) N = 3-33), and has negative Ba, Ta, Nb and Eu anomalies, resembling those of collision granitoids. The ükapili Granitoid has relatively high 87Sr/86Sr (i) ratios (0.711189-0.716061) and low εNd (t) values (-5.13 to -7.13), confirming crustal melting. In contrast, the enclaves are tholeiitic and metaluminous, and slightly enriched in LILEs (K, Rb) and Th, and have negative Ta, Nb and Ti anomalies; propose that they were derived from a subduction-modified mantle source. Based on mineral and whole rock chemistry data, the ükapili granitoid is H-(hybrid) type, post-collision granitoid developed by mixing/mingling processes between crustal melts and mantle-derived mafic magmas. 相似文献
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Please refer to the attachment(s) for more details. 相似文献
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Tuan D. Pham 《Mathematical Geology》1998,30(8):1039-1042
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Which is more hazardous: avalanche,landslide, or mudslide? 总被引：2，自引：0，他引：2
X.-Z. Xu Z.-Y. Liu W.-L. Wang H.-W. Zhang Q. Yan C. Zhao W.-Z. Guo 《Natural Hazards》2015,76(3):1939-1945
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The Yehlangian of Ting and Graban includes the Paoan shale,the Yülungshanlimestone,the Feihsienkuan shale and the Sanchiao limestone.In their opinion theseformations would represent the Upper Permian of south-western China.The presentpaper tries to show that both by their stratigraphical relation and their faunal contentsthe Yülungshan limestone and the Feihsienkuan shale belong undoubtedly to the LowerTriassic and that the Sanchiao limestone is much younger,probably of Upper Triassicage.The Paoan shale... 相似文献
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正Objective The Dahu quartz vein?style Au-Mo deposit is an important deposit in the Xiaoqingling region,which contains a total reserves of 38 tons of Au atanaverage grade of 6.8g/t and 100,000 tons of Mo at an average grade of 0.24%.It is hosted in the highly metamorphic 相似文献
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韩婷苇 《矿物岩石地球化学通报》2021,40(6):1431-1433
随着经济的快速发展,越来越多人选择乘坐飞机出行,还出现了往来于东亚(如北京、首尔、东京)和北美东海岸(如纽约、华盛顿)飞越地球北极的航线以节省时间和燃料.不过我们在享受飞机便捷体验的同时,也更加关注飞行期间受到的辐射问题.
从1912年奥地利科学家韦克多·赫斯(Victor Hess)通过探空气球发现了宇宙线(Cosmic Rays)的存在,到1991年国际辐射防护委员会(ICRP)建议将空勤人员列入职业受照人群进行辐射剂量管理,公众也越来越重视辐射问题.那么飞行中所受到的辐射是怎样的呢? 相似文献
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韩婷苇 《矿物岩石地球化学通报》2021,40(6):1431-1433
随着经济的快速发展,越来越多人选择乘坐飞机出行,还出现了往来于东亚(如北京、首尔、东京)和北美东海岸(如纽约、华盛顿)飞越地球北极的航线以节省时间和燃料.不过我们在享受飞机便捷体验的同时,也更加关注飞行期间受到的辐射问题.
从1912年奥地利科学家韦克多·赫斯(Victor Hess)通过探空气球发现了宇宙线(Cosmic Rays)的存在,到1991年国际辐射防护委员会(ICRP)建议将空勤人员列入职业受照人群进行辐射剂量管理,公众也越来越重视辐射问题.那么飞行中所受到的辐射是怎样的呢? 相似文献
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Liesbet Jacobs Olivier Dewitte Jean Poesen Damien Delvaux Wim Thiery Matthieu Kervyn 《Landslides》2016,13(3):519-536
With its exceptionally steep topography, wet climate, and active faulting, landslides can be expected to occur in the Rwenzori Mountains. Whether or not this region is prone to landsliding and more generally whether global landslide inventories and hazard assessments are accurate in data-poor regions such as the East African highlands are thus far unclear. In order to address these questions, a first landslide inventory based on archive information is built for the Rwenzori Mountains. In total, 48 landslide and flash flood events, or combinations of these, are found. They caused 56 fatalities and considerable damage to road infrastructure, buildings, and cropland, and rendered over 14,000 persons homeless. These numbers indicate that the Rwenzori Mountains are landslide-prone and that the impact of these events is significant. Although not based on field investigations but on archive data from media reports and laymen accounts, our approach provides a useful complement to global inventories overlooking this region and increases our understanding of the phenomenon in the Rwenzori Mountains. Considering the severe impacts of landslides, the population growth and related anthropogenic interventions, and the likelihood of more intense rainfall conditions, there is an urgent need to invest in research on disaster risk reduction strategies in this region and other similar highland areas of Africa. 相似文献
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Andrew H. Manning 《Hydrogeology Journal》2011,19(2):379-397
Noble gas recharge temperatures (NGTs) and radiocarbon ages were determined for 43 groundwater samples collected in the eastern Espa?ola Basin, New Mexico (USA), to identify mountain-block recharge in waters <10 thousand years (ka) old and to evaluate possible changes in mountain-block recharge over the past ??35?ka. For Holocene samples from the southeastern area, NGTs are dominantly 2?C4° cooler than the measured water-table temperature near the mountain front. Computed minimum mountain-block recharge fractions are dominantly 0.2?C0.5, consistent with previous large mountain-block recharge estimates. NGTs do not display the distinct low during the last glacial maximum observed in other paleorecharge studies; samples recharged 15?C25?ka ago are on average only 1.3° cooler than Holocene samples. Instead, samples with the coldest NGTs were recharged 25?C35?ka ago. A proposed explanation is that higher precipitation rates during the last glacial maximum resulted in a lower mean recharge elevation for the basin, essentially buffering the effect of the lower mean annual air temperature and producing NGTs similar to the Holocene. In the period preceding the last glacial maximum, precipitation rates more like today??s resulted in Holocene-like mountain-block recharge fractions, producing a mean NGT ??5° cooler than the Holocene, as expected. 相似文献
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Please?refer?to?the?attachment(s)?for?more?details. 相似文献
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Since the early 1900sPhragmites australis has been replacing other vegetation in Atlantic and gulf coast marshes at a rate of about 1% to 6% of the marsh surface per year. Vast areas of coastal marsh are now characterized by dense monotypic stands of this species. By virtue of its ability to build up the marsh surface,P. australis affects the landscape, hydrology, and hydroperiod of the marsh as well as drainage density, and other geomorphic features. Smoothed microtopography results in more difficult access to the marsh by nekton, and possibly reduced exchange of organic materials between the marsh and adjacent estuary. The pattern of replacement byP. australis results in fragmentation of existing stands ofSpartina alterniflora and other extant macrophytes, thereby altering landscape ecology and the ability of the marsh to support biodiversity and the production of marsh fauna. 相似文献
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Please refer to the attachment(s) for more details. 相似文献
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徐建峨 《沉积与特提斯地质》2006,26(1):110-110
1989年和2000年,国际地球科学协会(IUGS)的国际地层委员会(ICS)公布了一个“全球地层表”,其中,第三系被取消,新生界由古近系、新近系和第四系组成。2004年,ICS公布了新的地层年代表,第三系和第四系均被取消,新生界只包括古近系和新近系两个系,将新近系延长到现代。第三系和第四系术语的取消与保留,在国际上形成了赞成与反对两种意见。美国德克萨斯大学地球科学系的Amos Salvador在AAPG通报上发表文章,明确反对取消第三系和第四系。Amos Salvador查询了1980年以来的19种期刊,其中5种来自北美,3种来自拉丁美洲,9种来自欧洲,澳大利亚… 相似文献
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较热的早期地球通过板块构造机制消散较多的热量,一般来说总是通过较新岩石圈的消减。原则上这一过程可以由更长洋脊的快速扩张及其某些结合来完成,但是,目前的证据表明,新的大洋岩石圈比老的消减更慢。如果在太古宙也是这样,合适的解释就是“洋脊更长”。得到的定量表达式说明大洋的热散失与洋脊长度的立方根成比例,这一关系意味着如果太古宙热流是现在的3倍,那么就需要27倍于现在的洋脊长度,这说明在太古宙地球表面覆盖着许多移动缓慢的小板块。 相似文献
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【基本案情】2006年7月20日,某国有企业向A市政府请求对其一划拔土地进行出让,经批准后,便与A市国土资源局签订了委托出让手续,经评估等手续,A市国土资源局便将上述土地进行了公开挂牌出让。某房地产开发公司成功竞得该地块,当日房地产开发公司与A市国土资源局签订了《挂牌成交确认书》及《国有建设用地使用权出让合同》,在房地产开发公 相似文献