吉林基性超基性岩的地质特征及找矿方向   总被引：3，自引：0，他引：3  

冯守忠  路瑞春 《矿产与地质》1992,6(3):183-187

从多旋回大地构造演化的观点,分析吉林区域多旋回的构造运动,控制多旋回的基性超基性岩浆活动及其相应的成矿作用,认为与含镍有关的基性超基性岩体,主要受“台槽边界”赤峰—开源深断裂控制,沿深断裂一侧或两侧成带分布,分群集中。为铜镍矿床区域勘查工作,提供地质资料。  相似文献   

Heavy Metal Load of Sediments of the River Gurk (Carinthia/Austria) — Merits and Limitations of Sequential Leaching Schwermetallbelastung des Sediments der Gurk in Kärnten — Vorzüge und Einschränkungen sequentieller Löseverfahren     

M. Sager  W. Vogel 《洁净——土壤、空气、水》1993,21(1):21-32

By means of the analysis of sediments cored in the small river Gurk (Carinthia/Austria), the input of Ag, Cd, Ce, Cr, Hg, La, Mo, Ni, V, and W from a chemical industrial plant could be detected. To estimate the actual load, and to obtain data for comparison with other sites, both unsieved fine sediments and sediments sieved to 20 μm were investigated from the same cores. Environmental mobilities of toxic heavy metals (Co, Cr, Cu, Ni, Zn) have been shown by sequential leaching following Tessier/Förstner. In the last step, HNO₃ leaches a purely geogenic fraction, which is fairly constant along the investigated river. Whereas the additional Cr from the input of the chemical plant is mainly found in the oxalate-leachable fraction, short-time-load to unpolluted sediments in the laboratory is found mainly in hydroxylamine/acetic acid. Both is due to the high affinity of Cr to Fe- and Mn-oxides. Adsorption/desorption experiments reveal that the low carbonate content of the Gurk sediments increases the importance of Fe/Mn-oxides for the sorption of Cr compared to other samples containing carbonate. The Ni-load was primarily found in weak-acid-leachable and oxalate-leachable fractions. Similarly, the oxalate-leachable fraction is dominant for adsorption of other metals and phosphorus. Other interelement relationships among the amounts leached, which are attributable partly to carbonate-, silicate-, organic or coating phases, have been found by means of factor analyses together with marker fractions for each type.  相似文献   

NON-LINEAR CRITICAL LAYER IN EL NINO AND LA NINA YEARS AND FORMATION, MAINTENTENANCE AND OSCILLATION OF THE SUBTROPICAL HIGH     

陶丽  陆维松 《热带气象学报(英文版)》1999,5(2):113-122

Monthly mean zonal wind data from the European Center for Medium-range Weather Forecasting(ECMWF)for December 1982, April 1983, October 1984 and ApriI 1985 are used in numerical integration as thebasic flow in a non-linear critical-layer model. The subtropical high is extensive and limited in number if simulated with the basic now in December 1982 and April 1983. It consists of 2 to 3 cells that move westward at alloscillatory periods of 1～2 months. The subtropical high, simulated with the basic flow in October 1984 and April1 985. is weak and small in coverage, or distributed in strips that contain up to 4 cells. The high. merged or spillover a short time. is moving westward. The years 1982 ～1983 are a process of EI Niño while the years 1984-1985one of La Niña. lt is known from the chart of energy flux that it oscillates by a much larger amplitude and longerperiod in the EI Niño year than in the La Niña year. All the results above have indicated that the basic flow in the EI Niño year is enhancing the subtropical high lagging by about 4 months and that in the La Niña year is decay'ing it. It is consiStent with the well-known observational fact that the SSTA in the equatorial eastern Pacitlc ispositively correlated with the extent and intensity of the subtropical high in west Pacific lagging by 1～2 seasons.The result is also important for further study of the formation, maintenance and oscillation of the subtropicalhigh.  相似文献   

TYPHOON ACTIVITY IN NORTHWEST PACIFIC IN RELATION WITH EL NINO AND LA NINA EVENTS     

何敏  宋文玲  陈兴芳 《热带气象学报(英文版)》1999,5(2):153-162

Statistic and typical-year composition methods are used to study the northwest Pacific typhoon activities in relation with the EI Niño and La Niña events. The result indicates that the typhoon tends to be inactive in the EI Niño years and active in the La Niña years and it is also dependent on the onset and ending time and intensity of the events and areas of genesis of typhoons. With statistic features of the frequency of typhoon activity in the EI Niño and La Niña years and the time-lag correlation between the frequency and sea surface temperature(SST), useful information is provided for the prediction of typhoon occurrence. In addition, the singular values disassemble(SVD)method is applied to study the correlation between the geopotential field and SST field. The result shows that the air-sea coupling in the EI Niño years is unfavorable for the typhoon to develop. Which take place with a smaller number. Opposite situations are found with the La Niña years.  相似文献   

Intracrystalline fractionation of Fe in synthetic (Fe, Mg, Zn) - bearing staurolite: a Mössbauer spectroscopic study     

M. Koch-Müller  I. Abs-Wurmbach  W. Bubenik 《Physics and Chemistry of Minerals》1999,26(4):312-321

⁵⁷Fe-Mössbauer spectra of eleven Fe-Mg-bearing staurolite samples, synthesized at 5, 20 and 25 kbar and 680°C, ranging in composition from x_Fe?=1.00 to x_Fe?=0.15, and of two Zn-Fe-bearing staurolite samples, synthesized at 20 kbar and 700°C with x_Fe?=0.10 and x_Fe?=0.32 were collected at room temperature. The spectra reveal that about 80% of Fe_tot (in case of Fe-Mg-bearing staurolite) and about 70% of Fe_tot (in case of Fe-Zn-bearing staurolite) are located as Fe²⁺ at the three subsites Fe1, Fe2 and Fe3 of the tetrahedral T2-site. The refinement of the spectra results in almost identical values for the isomer shift (IS) (±1.0 mm/s) but significantly different values for the quadropole splitting (QS) for the three subsites which is in accordance with the different distortions of these sites. About 8% of Fe_tot (in case of Fe-Mg-bearing staurolite) and 13% of Fe_tot (in case of Fe-Zn-bearing staurolite) are located as Fe²⁺ at the octahedral M4 site, while the remainder percents of Fe_tot indistinguishably occur as Fe²⁺ at the octahedral M1 and M2 sites of the kyanite-like part of the structure. Within the whole Fe-Mg-staurolite solid solution series the Mössbauer parameters QS of the sites M4 and (M1, M2) vary systematically with composition whereas IS remains constant. There is a high negative correlation of the total Mg-content with Fe-occupation of all the Fe-bearing sites indicating a continuous substitution of Fe²⁺ by Mg on all these sites. Synthetic Fe-staurolites show no increasing occupation of the octahedral sites by two-valent cations with pressure, as was assumed by several authors.  相似文献   

A ∼6100 14C yr record of El Niño activity from the Galápagos Islands     

Melanie A. Riedinger  Miriam Steinitz-Kannan  William M. Last  Mark Brenner 《Journal of Paleolimnology》2002,27(1):1-7

Lithostratigrahic and mineralogic analyses of sediments from hypersaline Bainbridge Crater Lake, Galápagos Islands, provide evidence of past El Niño frequency and intensity. Laminated sediments indicate that at least 435 moderate to very strong El Niño events have occurred since 6100 ¹⁴C yr BP (7130 cal yr BP), and that frequency and intensity of events increased at about 3000 ¹⁴C yr BP (3100 cal yr BP). El Niño activity was present between 6100 and 4000 ¹⁴C yr BP (4600 cal yr BP) but infrequent. The Bainbridge record indicates that there has been considerable millennial-scale variability in El Niño since the mid-Holocene.  相似文献   

Ice flow direction during late Paleozoic glaciation in western Paraná Basin, Brazil     

A. L. D. Gesicki  C. Riccomini  P. C. Boggiani   《Journal of South American Earth Sciences》2002,14(8)

The recent discovery of ice-striated surfaces associated with the late Paleozoic Aquidauana Formation suggests that glaciers coming from southwest Africa reached westernmost parts of the Paraná Basin in central Brazil. Abrasion features were developed by glaciers moving from SSE towards NNW, mainly on an unconsolidated bed. These records expand to about 1,050,000 km², the coverage of the late Paleozoic glaciation in the region of the Paraná Basin in Western Gondwana.

Resumen

A recente descoberta de superfícies estriadas associadas à Formação Aquidauana, de idade permocarbonífera, sugere que as geleiras provenientes do sudoeste da África alcançaram as porções ocidentais da Bacia do Paraná, na região central do Brasil. As feições de abrasão foram geradas pelo deslocamento de geleiras de SSE para NNW, principalmente sobre substrato inconsolidado. Estes novos registros evidenciam que a glaciação neopaleozóica cobriu uma área de pelo menos de 1.050.000 km² na região ocupada pela Bacia do Paraná no Gondwana Ocidental.  相似文献   

Conceptual model about the interaction between El Ni(n)o/ Southern Oscillation and Quasi-Biennial Oscillation in far west equatorial Pacific     

LIU Qinyu  LIU Zhengyu  PAN Aijun 《中国科学D辑(英文版)》2006,49(8)

Interaction between the Quasi-Biennial Oscillation in far west equatorial Pacific (QBOWP) and the El Nino/Southern Oscillation (ENSO) is studied using a new conceptual model. In this conceptual model, the QBOWP effects on ENSO are achieved through two ways: (1) the oceanic Kelvin wave along equatorial Pacific, and (2) the Atmospheric Walker Circulation anomaly, while ENSO effects on QBOWP can be accomplished by the atmospheric Walker Circulation anomaly. Diagnosis analysis of the model results shows that the Atmospheric bridge (Walker circulation) plays a more important role in interaction between the ENSO and QBOWP than the oceanic bridge (oceanic Kelvin wave along equatorial Pacific); It is found that by the interaction of the ENSO and QBOWP, a free ENSO oscillation with 3-5 years period could be substituted by a oscillation with the quasi-biennial period, and the dominant period of SST anomaly and wind anomaly in the far west equatorial Pacific tends to be prolonged with enhanced ENSO forcing. Generally, the multi-period variability in the coupled Atmosphere-Ocean System in the Tropical Pacific can be achieved through the interaction between ENSO and QBOWP.  相似文献   

热带太平洋地区风场异常和与El Ni(~n)o有关的年际变化   总被引：1，自引：1，他引：1  

薛洪斌  张铭  王业桂 《气候与环境研究》2006,11(4)

利用1964～1993年NCEP/NCAR再分析风应力资料和中国科学院大气物理研究所发展的14层热带太平洋环流模式(OGCM),对热带太平洋与El Ni(~n)o有关的年际变化进行了研究.首先,分析了西太平洋暖池次表层海温异常(SOTA)与Ni(~n)o 3区海表温度异常(SSTA)的年际变化关系,发现在El Ni(~n)o事件之前,暖池的次表层海温都有明显正异常出现,它的东传导致了El Ni(~n)o的发生,并且SOTA的传播随纬度变化,沿赤道东传,在赤道外西传.然后,选取了20世纪70年代和80年代两次最强的El Ni(~n)o事件讨论了引起这种机制的可能原因--西风异常的作用.最后,对1964～1993所有的El Ni(~n)o年的风场、次表层海温和海表温度的异常进行了综合分析.  相似文献   

Negotiating changing livelihoods: The sampan dwellers of Tam Giang Lagoon, Vi?t Nam     

Elsa DaCosta 《Geoforum》2007,38(1):190-206

Central Vi?t Nam is one of the most vulnerable areas in the country to natural disasters. In 1985 a major typhoon hit the Tam Giang Lagoon coastal area in the province of Th?a Tiên-Hu?, Central Vi?t Nam, with severe impacts on the sampan dwellers who lived there on boats and fished for their livelihoods. Since then, the government has attempted to resettle them on land in order to decrease their vulnerability to such events. Consequently, this process has changed the livelihood options as well as the social networks of the sampan dwellers. This study of the resettlement village of Th?y ?i?n analyses the social networks and different forms of social capital being utilised by the resettled sampan dwellers as part of their changing livelihoods and questions whether the social capital formed will indeed lead to a long term decrease in vulnerability. It is found that while bonding and linking social capital have been newly formed, the trust required for bridging social capital formation is still missing, and this in turn is hindering the possibilities of sustainable livelihood formation.  相似文献