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51.
52.
我国首次发现的镉银黝铜矿 总被引:2,自引:0,他引:2
我们发现的镉银黝铜矿产于青海省锡铁山铅锌矿床氧化带中,颗粒细微,最大颗粒为30μm,一般为2—5μm,平均颗粒为3μm。4个颗粒的电子探针分析结果(%)是:Ag15.582—17.503,平均16.863; Cu22.419—23.555,平均22.802;Cd9.042—11.966,平均10.748;Zn0.175—1.007,平均0.516;Fe0.050—1.528,平均0.426;Sb24.970—26.247,平均25.691;As0.871—1.216,平均0.988;S20.960—21.823,平均21.507。根据平均化学成分计算的分子式为;(Cu_(6.95)Ag_(3.03))_(9.98)(Cd_(1.86)Zn_(0.15)Fe_(0.15))_(2.15)(Sb_(4.09)As_(0.25))_(4.34)S_(13),简化式为Cu_(10)Cd_2Sb_4S_(13)。 相似文献
53.
Carbonate carbon sequestration(CS) can aid in solving the problem of terrestrial residual carbon sinks and imbalances in the global carbon budget. Thus, complete understanding of the magnitude, spatiotemporal distribution, and evolution of this sequestration is highly desirable. On the basis of random forest regression and maximal potential dissolution model for carbonate, we estimated the CS of typical carbonate weathering in China from 2000 to 2014, that is, the sequestration of limestone weathering, using long-term ecologic, meteorological, hydrological raster data, and monitored data from 44 watersheds in China and surrounding regions. We extended our analyses by systematically exploring the spatiotemporal pattern and evolution trend of the flux and total sequestration. High levels of ionic activity coefficients of Ca~(2+) and HCO_3~- in limestone regions were observed to be mainly distributed in Northern and Northwestern China with a clear gradient from northwest to southeast. With a contrary spatial pattern, the annual average CS flux(CSF) of limestone weathering in China was estimated to be 4.28 t C km~(-2) yr~(-1), with high values mainly in the karst zones in Southeastern China. The mean CSF in different latitudes showed that Southern China(south of 28.14°N) was the region with the largest interannual fluctuation of flux and CSF increases as latitude decreases. The mean CSF in subtropical and tropical(TR) regions was the maximum of all major climate types, and for the frigid(F), mid-temperate(MTE), warm temperate(WTE), and temperate(TE) major climates; the CSF in the desert(D)subdivided climate was the minimum of these climates. By contrast, the values in grassland(G) and broad-leaved forest subdivided climate were the maximum. The pixel-based trend analysis indicated that the CSF of limestone weathering in China was slightly increasing in the period 2000–2014 with a rate of 0.036 t C km~(-2) yr~(-1). Furthermore, the annual total CS was estimated to be 7.07 Tg carbon per year(Tg C yr~(-1)) with high levels in 2002, 2008, and 2010, and the minimum appeared in 2011 with a slightly increasing trend of the total CS being observed with a rate of 0.06 Tg C yr~(-1). Tibet Autonomous Region was the administrative division with the largest total CS of limestone weathering(1.20 Tg C yr~(-1)) in China, and karst zones in Southeastern China had the largest total CS(4.95 Tg C yr~(-1)) which accounts for 70.01% of that in the three divided karst regions. On the basis of the diversity of rock chemical weathering carbon cycle mechanisms of different carbonate rock types, we estimated that the total CS of carbonate weathering in China may reach 11.37 Tg C yr~(-1)(the sink was approximately 5.02 t C km~(-2) yr~(-1)),which amounts to 16.20% of the total biomass CS in China, furthermore, the CSF of carbonate weathering in China can reach6.54 t C km~(-2) yr~(-1) if excluding the interference of the negative runoff. This finding indicates that CS of carbonate weathering is an indispensable part of China's terrestrial carbon sink system. The research pattern of this study was important for further improving the accuracy of the estimation for the global carbonate weathering carbon sink. 相似文献
54.
牡丹江地区蓝片岩中脉状青铝闪石~(40)Ar—~(39)Ar年龄及其地质意义 总被引:2,自引:0,他引:2
对穆棱县的磨刀石、椅子圈地区的蓝片岩研究,确定其经受过三期叠加变质作用:第一期为蓝片岩相变质作用;第二期为蓝闪绿片岩相变质作用;第三期为受断裂构造控制的动力变质作用,形成脉状青铝闪石、钠长石等变质矿物。通过对脉状产出的青铝闪石 ̄(40)Ar— ̄(39)Ar年龄测定,获得较好的年龄谱,坪年龄为154.7±0.7Ma。此年龄表明了该期变质作用与敦—密断裂发生大规模左行走滑有关,由于大型走滑断裂造成局部构造超高压,诱发了原有的蓝片岩中流体活化,而形成青铝闪石、钠长石、绿帘石等矿物组成的脉体沿剪切面分布。 相似文献
55.
56.
塔里木盆地北部库车前陆褶皱-冲断带构造-地层层序可划分为中生界盐下层序、古新统一始新统盐层层序和渐新统一第四系盐上层序。盐岩层序的岩性主要为灰白色、浅灰色盐岩、膏岩、泥灰岩和紫红色碎屑岩,厚110~3000 m。盐岩层的存在使库车前陆褶皱-冲断带发育-系列盐相关构造,其中最引人注目的是盐推覆构造。野外地质调查、地震资料解释、遥感资料和钻井资料揭示,沿库车前陆褶皱-冲断带前缘西秋立塔克山发育大型盐推覆构造,总体呈近东西走向,并略呈往西南凸出的弧形展布,沿走向延伸超过200km,由北往南逆冲推覆距离达30km以上。主断层沿古新统-始新统盐岩层发育,外来推覆体由古新统-始新统盐层层序和渐新统-第四系盐上层序组成,表现为受断层控制的单面山,逆冲推覆在原地中生代-新生代地层之上。地质分析和剖面复原结果表明,盐推覆构造主要形成于新近纪末期以来的喜马拉雅晚期阶段,现今仍具有强烈的活动性。由于不均匀推覆作用,在盐推覆构造的不同地段,逆冲推覆距离、冲断层产状、外来岩系和原地岩系的叠置关系以及盐相关构造的发育都有较大差异,显示出走向上分段性特点。库车前陆褶皱-冲断带前缘盐推覆构造的形成演化受区域挤压作用、重力滑动和重力扩展作用控制。 相似文献
57.
Guofeng Zhu Yu Zhang Yuanqing He Junju Zhou Hanxiong Pan Huiwen Guo Huiying Ma Xinggang Ma Lei Feng 《Environmental Earth Sciences》2018,77(22):765
97735 artificial reservoirs have been built in China since 1950s, which could guarantee the supply of urban water and agricultural irrigation. In arid oasis area, only the water of reservoir is available as water resource. The study of hydrochemical characteristics is the prerequisite for evaluating the water quality of domestic water and irrigation water. In the Hongyashan Reservoir, the middle of the Shiyang River Basin and the Tengger desert and Badain Jaran desert, water samples were taken at different points of the lake for about 3 years. The chemical characteristics of the lake water and their influencing factors were studied. The results of the samples for the test have shown that water of the Hongyashan Reservoir is weakly alkaline. And the main compositions of ions in the water are Ca2+ and \(\text{HCO}_{3}^{ - }\), hydrochemical type is Ca–HCO3. In terms of the seasonal variation of Hongyashan Reservoir, except for \(\text{NO}_{3}^{ - }\), the ions in the rest of the water showed roughly the same changeable characteristics in that the composition of ion is higher in summer and autumn, but lower in winter and spring. This is consistent with the seasonal variation in runoff ions throughout the Shiyang River Basin. Ionic characteristics are consistent with the ionic values of dry lakes in the world, which are suitable for urban water and water for irrigation, but are slightly higher than the global lake background standard. Carbonate weathering products are the main source of water ions in Hongyashan Reservoir, and evaporation also affects the ion characteristics of water. 相似文献
58.
冀西北红旗营子群变质与变形的温压条件研究 总被引:4,自引:0,他引:4
红旗营子群及其中的古老岩体共同经历了低角亲岩相的变质作用和近东西向的褶皱变形作用,表1-8给出了石榴石,黑云母,角亲石,斜长石电子探针分析结果及有关参数,6个石榴石-黑云母对测温结果平均为609℃,2个角闪石-斜长石对测温结果平均为610℃,9个斜长石菱切面角构造变形温度测定结果,平均为637℃,由此推测变质与变形是同时的,变形高峰稍早于变质高峰。 相似文献
59.
Jianying MA Wei SUN Huiwen ZHANG Dunsheng XIA Chengbang AN Fahu CHEN 《Frontiers of Earth Science》2009,3(1):107-111
The stable carbon isotope composition in surface soil organic matter (δ13Csoil) contains integrative information on the carbon isotope composition of the standing terrestrial plants (δ13Cleaf). In order to obtain valuable vegetation information from the δ13C of terrestrial sediment, it is necessary to understand the relationship between the δ13C value in modern surface soil and the standing vegetation. In this paper, we studied the δ13C value in modern surface soil organic matter and standing vegetation in arid areas in China, Australia and the United States.
The isotopic discrepancy between δ13Csoil and δ13Cleaf of the standing dominant vegetation was examined in those different arid regions. The results show that the δ13Csoil values were consistently enriched compared to the δ13Cleaf. The δ13Cleaf values were positively correlated with δ13Csoil, which suggests that the interference of microorganisms and hydrophytes on the isotopic composition of surface soil
organic matter during soil organic matter formation could be ignored in arid regions. The averaged discrepancy between δ13Csoil and δ13Cleaf is about 1.71%in Tamarix L. in the Tarim Basin in China, 1.50% in Eucalytus near Orange in Australia and 1.22% in Artemisia in Saratoga in the United States, which are different from the results of other studies. The results indicate that the discrepancies
in the δ13C value between surface soil organic matter and standing vegetation were highly influenced by the differences in geophysical
location and the dominant species of the studied ecosystems. We suggest that caution should be taken when organic matter δ13C in terrestrial sediment is used to extract paleovegetation information (C3/C4 vegetation composition), as the δ13C in soil organic matter is not only determined by the ratio of C3/C4 species, but also profoundly affected by climate change induced variation in the δ13C in dominant species. 相似文献
60.
Mobile user identification aims at matching different mobile devices of the same user using trajectory data, which has attracted extensive research in recent years. Most of the previous work extracted trajectory features based on regular grids, which will lead to incorrect feature representation due to lack of geographic information. Besides, most trajectory similarity models only considered one single distance measure to calculate the similarity between users, which ignore the connection between different distance measures and may lead to some false matches. In light of this, we present a novel user identification method based on road networks and multiple distance measures in this article. The proposed method segments a city map into several grids and road segments based on road networks. Then it extracts location and road information of trajectories to jointly construct user features. Multiple distance measures are fused by a discriminant model to improve the effect of user identification. Experiments on real GPS trajectory datasets show that our proposed method outperforms related similarity measure methods and is stable for mobile user identification. Meanwhile, our method can also achieve good identification results even on sparse trajectory datasets. 相似文献