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61.
黔西南泥堡—包谷地卡林型金矿田以泥堡特大型金矿床为主体,兼具一系列小型金矿床和新发现金矿点。本文在矿田内系统采集了与成矿密切相关的石英、方解石、萤石和辉锑矿样品,分析微量元素和稳定同位素地球化学特征,探讨成矿流体性质及来源。分析结果显示,石英、方解石和萤石整体上富集As、Sb、Li、Sr、W等元素,其中As、Sb成矿元素继承了成矿流体的特征;Sb成矿元素与Bi、W、Mo、Co、Ni等亲岩浆元素相关性较好,显示成矿与岩浆活动有关。方解石、萤石显示MREE富集,方解石具有显著的Eu正异常,反映了成矿流体在矿物沉淀时的稀土配分特征,并且处于相对酸性和还原的状态。石英δDV-SMOW、δ18OV-SMOW和δ13CV-PDB分别为-76‰~-55.7‰(均值-64.9‰)、16.5‰~24.5‰(均值21.1‰)、-14.3‰~-7.0‰(均值-10.9‰),辉锑矿δ34SV-CDT值为-0.4‰、-0.6‰和1.9‰,方解石δ13CV-PDB和δ18OV-SMOW分别为-6.5‰~-2.5‰(均值-4.5‰)、16.2‰~22.4‰(均值18.7‰)。综合研究区内分析和收集的C、H、O和S同位素结果,表明成矿流体可能主要来源于岩浆流体,并有部分地层水加入。结合区域地球物理和年代学资料,认为黔西南卡林型金矿成矿可能与深部岩浆活动有关,而与区域上出露的基性—超基性岩浆岩没有直接的成因联系。  相似文献   
62.
张明  解广轰 《地球化学》1996,25(5):425-444
对中国东部赋存于新生代玄武岩中的地幔岩捕虏体的全岩和单斜辉石等作了主元素和微量元素分析,证实了二辉橄榄岩及其单斜辉石在主元素有连续变化的趋势,反映了具部分熔融后残留相的性质。方辉橄榄岩及其中的单斜辉石的主元素,Nd/Yb,Ti/Zr和Sr/Zr值与二辉橄榄岩的同类矿物是不连续过渡。  相似文献   
63.
沔阳—当阳前陆盆地自北而南可划分为五个构造单元 :桐柏山—大别山基底卷入推覆构造带、南大巴山—大洪山叠瓦逆冲断裂构造带、沔阳—当阳拗陷变形带、宜昌—沙市前陆斜坡带、黄陵—松滋前缘隆起带。盆地的形成与南大巴山—大洪山造山带的发育密切相关。盆地经历了加里东期、海西—印支期南秦岭洋盆、北华南洋盆的两次“开 (降 )、合 (升 )” ,燕山早期陆内俯冲造山成盆及燕山晚期—喜马拉雅期陆内伸展断陷的演化。盆地油气资源丰富 ,具三套有效烃源岩 :晚奥陶世—早志留世广海陆棚相泥页岩 ,二叠纪滨岸沼泽相含煤泥岩 ,晚三叠世—早侏罗世湖泊—沼泽相暗色泥页岩、煤系泥岩和煤岩。中三叠世—早第三纪为油气生成高峰期。油气运移指向主要为南西方向的前缘隆起  相似文献   
64.
牛凡  王涛  廖光洪 《海洋学报》2020,42(5):65-76
有效重力势能作为重力势能中活跃的部分,能够参与海洋能量循环。本文计算和评估了CMIP5中9个模式的全球大洋2 000 m以上积分的有效重力势能和200~500 m深度范围内的中尺度有效重力势能,并与由BOA_Argo观测数据计算的结果进行比较。分析表明,就全球大洋2 000 m以上积分的有效重力势能而言,多数模式的计算结果均大于由Argo观测数据计算的结果。通过比较有效重力势能的空间分布特征,发现在强动力活跃区(特别是黑潮、湾流、南极绕极流区),模式与观测相差较大,其差别主要来源于观测与模式中扰动密度的差异。此外,在黑潮和南大洋区域,涡动能和有效重力势能具有较高的时间相关性,而在北大西洋湾流区域,两者的相关性较低;功率谱分析显示中尺度有效重力势能与涡动能都存在显著的半年和年变化周期。  相似文献   
65.
广州市CORS系统实时动态定位精度测试   总被引:2,自引:0,他引:2  
分析了GZCORS试运行阶段的实时动态GPS定位数据,验证了其实时动态定位初始化时间、定位精度、时间可用性等都优于设计精度,表明了其具有很好的定位精度和稳定性.  相似文献   
66.
Wind data from NCEP and hydrographic data obtained during 8–27 March 1992 have been used to compute circulation in the Luzon Strait and the northern South China Sea using three-dimensional diagnostic models with a modified inverse method. Numerical results are as follows: the main Kuroshio is located above 800 m levels. It has two intrusive branches of the Kuroshio in the areas above 400 m. One part intrudes anti-cyclonically northwestward, then flows through the area above 200 m southwest of Taiwan and into the Taiwan Strait. The other part intrudes westward and flows cyclonically in the areas north of the cyclonic eddies, then flows southward through the southern boundary of the region. The net westward volume transport (VT) through Section at 120°15′E between Luzon Island and Taiwan Island is about 3.0 Sv, net northward VT through northern boundaries into the Taiwan Strait is about 1.4 Sv and net southward VT through southern boundaries is about 1.6 Sv, which finally flows into the Karimata and Mindoro Straits. In the areas above 400 m east of 117°15′E, the circulation is mainly dominated by the basin-scale cyclonic gyre, which consists of two cyclonic eddies. However, in the areas below 400 m east of 119°00′E, the circulation is mainly dominated by basin-scale anti-cyclonic gyre. The joint effect of baroclinity and relief and interaction between wind stress and relief are important in different area respectively for the pattern of the depth-averaged flow across contours of fH−1.  相似文献   
67.
Cenozoic lavas from Hainan Island,South China,comprise quartz tholeiite,olivine tholeiite,alkali basalt,and basanite and form a continuous,tholeiite-dominated,compositional spectrum.Highly incompatible elements and their relationships with isotopes in these lavas are shown to be useful in evaluating mantle-source composition,whereas modeling suggests that ratios of elements with bulk partition coefficients significantly larger than those of Nb and Ta may be sensitive to partial melting.Th/Ta and La/Nb ratios of alkali basalts are lower than those of tholeiites,and they are all lower than those of the primitive mantle,These ratios correlate positively with ^207Pb/^204Pb and ^87Sr/^86Sr ratios.Such relationships can be explained by mixing of depleted and enriched source components.A depleted component is indicated by alkali basalt compositions and is similar to some depleted OIB (PREMA).The enriched component,similar to sediment compositions,is indicated by tholeiites with high LILE/HFSE,^207Pb/^204Pb,and ^87Sr/^86Sr ratios.In general,basalts from Hainan and the South China Basin(SCB)share common geochemical characters.e.g.high Rb/Sr,Th/Ta,^207Pb/^206Pb,and low Ba/Th ratios.Such a geochemical trend is comparable to that of EMII-type OIB and best explained as the result of subduction.Occurrence of these characteristics in both continental Hainan basalts and SCB seamout basalts indicates the presence of a South China geochemical domain that exists in the mantle region below the lithosphere.  相似文献   
68.
The wind data from NCEP and hydrographic data obtained from April 22–May 24, 1998 have been used to compute the circulation in the South China Sea (SCS) using three dimensional diagnostic models. The main numerical results with SSHA derived from T/P altimeter are as follows: most of intruded Kuroshio bypasses. However, a part of Kuroshio intrudes westward above 300 m levels. This intruded westward flow is narrowly confined to the continental slope south of China, in agreement with the findings of Qu et al. (2000). The basin-scale cyclonic gyre dominates in the northern SCS and consists of two cyclonic eddies, C2 and C3, above 300 m levels. However, it is separated into two parts by an anti-cyclonic eddy, W4, below 300 m. The basin-scale anti-cyclonic gyre dominates in the central SCS and consists of three anti-cyclonic eddies, W1, W2 and W3, above 300 m levels. However, below 300 m it consists of the anti-cyclonic eddies W1, W2 and W4 and extends northward to near 20°N. A northward coastal jet is present near the coast of Vietnam at depths above 300 m, and develops northward further to about a distance of 3°15′ N than that in cruise 2. The most important dynamical mechanism is due to the joint effect of the baroclinity and relief. The second dynamical mechanism is due to the interaction between the wind stress and relief. The topography effect is more important than the β effect. The Sverdrup relation cannot be satisfied in the SCS.  相似文献   
69.
The data, measured by a three-wavelength Integrating Nephelometer over Lanzhou City during the winters of 2001/2002 and 2002/2003 respectively, have been analyzed for investigating the scattering properties of atmospheric aerosols and exploring their relationship and the status of air pollution. The aerosol particle volume distribution is inverted with the measured spectral scattering coefficients. The results show that the daily variation of the aerosol scattering coefficients is in a tri-peak shape. The average ratio of backscattering coefficient to total scattering coefficient at 550 nm is 0.158; there exists an excellent correlation between the scattering coefficients and the concentration of PM10. The average ratio of the concentration of PM10 to the scattering coefficients is 0.37g m^-2, which is contingent on the optical parameters of aerosol particles such as the size distribution, etc.; an algorithm is developed for inverting the volume distribution of aerosol particles by using the histogram and Monte-Carlo techniques, and the test results show that the inversion is reasonable.  相似文献   
70.
岩体风化的综合分带研究   总被引:23,自引:4,他引:23  
岩体的风化不仅会引起岩石物质成份、化学成份变化 ,而且也引起岩体裂隙、岩体完整性的改变。因而风化岩体中裂隙数量、岩体块度的变化与岩体的风化程度具有较好的对应关系。论文研究了用岩体裂隙间距、岩体的完整性指标、岩石质量指标对岩体风化程度进行分带 ,较好地将岩体风化分带与岩体结构、岩体工程特性紧密地结合起来。在岩体风化程度的定量划分上作了新的探索。  相似文献   
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