安徽铜陵矿集区海底喷流沉积体系的流体包裹体微量元素对比

铜陵矿集区与铜-金(多金属)矿床有关的热液活动主要有两大体系。即与海西期海底喷流沉积有关的热液体系和与矽卡岩矿化有关的燕山期岩浆热液体系。查明这两类热液体系的流体包裹体特征对区域找矿和矿床成因研究都有实际意义。在包裹体岩相学研究基础上，应用ICP-MS技术和热爆提取方法，研究了新桥、冬瓜山、峙门口、铜官山、朝山等矿床具代表性的热液石英中流体包裹体的微量元素、稀土元素特征。结果表明，两类热液体系在流体包裹体特征上有较大的区别，在流体的微量元素和稀土元素特征方面也很不相同。海底喷流沉积体系的热液石英中流体包裹体与岩浆热液体系的相比。稀土总量较高，LREE／HREE比值较大，δEu不明显。且Mo／(W Sn)比值较高，反映流体中成矿物质的深源特征；Ga／T1、Rb／Cs大。Zr／Hf低，也不同于岩浆热液体系。     

铜陵地区老鸦岭层状钼矿床铅同位素组成研究

安徽铜陵老鸦岭矿床中二叠系大隆组(P2d)顶部的含矿(钼矿化)黑色页岩以及附近(立新煤矿)同一层位不含矿黑色页岩的实测铅同位素组成分别为：^206Pb/^204Pb20.20～22.37,^207Pb/^204Pb15.67～15.82,^208Pb/^204Pb38.47～38.60和^206Pb/204Pb18.83～20.80,^207Pb/^204Pb15.65～15.76,^208Pb/^204Pb38．84～39．22。对137Ma的放射成因Pb进行校正后的铅同位素组成表明，含矿黑色页岩和不含矿黑色页岩均与燕山晚期火成岩无关，老鸦岭含矿黑色页岩可能具沉积成因。对沉积(约250Ma)以来的放射成因Pb进行校正后的铅同位素组成表明：不含矿黑色页岩的Pb源自上地壳，而含矿黑色页岩的Pb(因而推测其他成矿金属)可能源于上地壳物质(与不含矿黑色页岩的Pb源相似)与下地壳物质的混合。     

青藏高原祖尔肯乌拉山地区火山岩Ar-Ar年代学初步研究

对祖尔肯乌拉山地区 4个火山岩样品进行了Ar -Ar年龄测定 ,其坪年龄分别为 (40 91± 1 18)Ma、(41 0 7± 0 80 )Ma、(42 0 0± 1 31)Ma、(39 0 0± 2 0 6 )Ma。它们代表了这些火山岩的形成时代 ,表明本区在古近纪始新世中期发生过大规模的火山活动     

基于GIS的孔隙水文地质层三维空间离散方法

针对自然界中孔隙水文地质层空间分布的不连续性与厚度分布的不均匀性,研究基于GIS的孔隙水文地质层三维空间离散实现的技术路线,提出基于GIS的孔隙水文地质层不规则六面体元的三维空间离散方法.该法不仅能最大限度地保证不规则六面体元中水文地质层类型的一元性,而且可充分利用GIS的空间分析与数据的自动提取功能,快速提取各个计算结点上空间位置坐标与各类计算参数,大大缩短水文地质模型空间离散与相关数据文件组织所需的时间,提高地下水三维有限差分数值模拟的时效性,具有较高的实用价值.     

南秦岭十里坪锑矿床成矿时代及成因的初步研究

十里坪锑矿床受赵川陆缘隆_滑构造的主滑脱拆离带的控制。矿体呈脉状赋存于韧_脆性主滑脱带上部的脆性次级断层_节理中,矿石类型主要为萤石石英辉锑矿型。围岩为太古宙_元古宙变质岩系,围岩蚀变弱。成矿流体属H2O_CO2_NaCl体系,流体包裹体盐度w(NaCleq)为3.6%～11.3%,均一温度为109～232℃,形成压力大致为800×105Pa。硫、铅同位素研究表明,矿质主要来源于变火山岩围岩;氢、氧同位素显示,成矿流体以大气降水为主,初步将该矿床定为变质岩源就地式大气降水热液矿床。矿石中萤石Sm_Nd等时线年龄为(392±24)Ma,与南秦岭北部晚古生代拗陷区热水喷流_沉积成矿时代相一致,它们都形成于秦岭微板块泥盆纪非造山裂解阶段。     

鄂尔多斯盆地中生代晚期以来大地热流的变化及其对生态环境格局和演变的影响

鄂尔多斯盆地的西北部、东北部和南部三个区域现今大地热流平均值分别为56．3、67．3和65．3mW／m^2，对应的生态环境格局也有明显的差异。研究表明，大地热流每增加4～5mW／m^2可使年均地表温度升高约l℃，使最低月均地表温度升高2。C以上。鄂尔多斯盆地东北部的平均大地热流比西北部高出11mW／m^2，东北部年均地表温度可能比西北部高出2～3℃，其最低月均地表温度可能比西北部高出4～6℃。西北部的大地热流平均值已经低于维持地表生态系统延续所需大地热流的临界值(57mW／m^2)，其自然生态系统整体上已经处于脆弱境地；东北部和南部的大地热流均大于57mW／m^2，自然生态系统均尚较稳健。东北部的沙漠化可能是风沙侵入的结果，其生态应该是可以恢复的。整个西北部作为一个整体看，72万年以前大地热流就已衰减到临界值以下，区域生态系统渐趋脆弱，开始整体上向荒漠化演变。     

碳酸岩Sr、Nd、Pb 同位素地球化学研究评述

碳酸岩是出露相对较少的幔源岩石，其中Sr与Nd是研究地幔物质组成的主要对象之一。本文统计了世界上主要碳酸岩的锶、钕、铅同位素组成特征；研究显示，碳酸岩源区主要是洋岛玄武岩高U／Pb的HIMU端员和富集端员(EM1或EM2)的混合作用；此外大部分碳酸岩的锶、钕同位素落在大洋玄武岩范围内；这些均表明其成因与地慢柱有密切联系。碳酸岩及与之共生的硅酸岩的同源或独立源区模式部很难充分解释两者同位素组成特征，逭反映碳酸岩的演化模式涉及更复杂的过程。可能是俯冲作用使碳酸岩源区经历不同时间和程度的富集、亏损过程导致地幔源区成分不均一。     

基于GPS掩星技术反演大气参数模型的优化

准确掌握地球大气中的水气分布，了解水气变化趋势对天气现象、全球气候变化、数值预报具有理论研究及实用价值。以无线电掩星技术为基础，利用掩星数据反演大气参数剖面。对原反演模型的不足进行了论证，并给出了反演个例。详细地论述了通过引入MM5先验温度T再通过线性迭代的方法反演对流层下部水汽廓线原理，给出了优化后模型反演个例。并对模型优化后反演廓线中存在的问题进行了分析，提出了下一步优化方向。     

REE and (э)Nd of clay fractions in sediments from the eastern Pacific Ocean: Evidence for clay sources

Clay fractions in the non-calcareous surface sediments from the eastern Pacific were analyzed for clay minerals, REE and 143Nd/144Nd. Montmorillonite/illite ratio (M/I ratio), total REE contents ((REE), LREE/HREE ratio and cerium anomaly (бCe) may effectively indicate the genesis of clay minerals. Clay fractions with M/I ratio >1, бCe (0.85, (REE (400 μg/g, LREE/HREE ratio (4, and REE patterns similar to those of pelagic sediments are terrigenous and autogenetic mixed clay fractions and contain more autogenetic montmorillonite. Clay fractions with M/I ratio <1, бCe=0.86 to 1.5, ΣREE=200 to 350 μg/g, LREE/HREE ratio (6 and REE distribution patterns similar to that of China loess are identified as terrigenous clay fraction. The 143Nd/144Nd ratios or (э)Nd values of clay fractions inherit the features of terrigenous sources of clay minerals. Clay fractions are divided into 4 types according to (э)Nd values. Terrigenous clay minerals of type I with the (э)Nd values of -8 to -6 originate mainly from North American fluvial deposits. Those of type II with the (э)Nd values of -9 to -7 are mainly from the East Asia and North American fluvial deposits. Those of type III with (э)Nd values of -6 to -3 could come from the central and eastern Pacific volcanic islands. Those of type IV with (э)Nd values of -13 to -12 may be from East Asia eolian. The terrigenous and autogenetic mixed clay fractions show patchy distributions, indicating that there are volcanic or hot-spot activities in the eastern Pacific plate, while the terrigenous clay fractions cover a large part of the study area, proving that the terrigenous clay minerals are dominant in the eastern Pacific.     

The diurnal and seasonal characteristics of urban heat island variation in Beijing city and surrounding areas and impact factors based on remote sensing satellite data

Based on the land surface temperature (LST), the land cover classification map,vegetation coverage, and surface evapotranspiration derived from EOS-MODIS satellite data, and by the use of GIS spatial analytic technique and multivariate statistical analysis method, the urban heat island (UHI) spatial distribution of the diurnal and seasonal variabilities and its driving forces are studied in Beijing city and surrounding areas in 2001. The relationships among UHI distribution and landcover categories, topographic factor, vegetation greenness, and surface evapotranspiration are analyzed. The results indicate that: (i) The significant UHI occur in Beijing city areas in the four seasons due to high heat capacity and multi-reflection of compression building, as well as with special topographic features of its three sides surrounded by mountains,especially in the summer. The UHI spatial distribution is corresponding with the urban geometry structure profile. The LST difference is approximately 4-6℃ between Beijing city and suburb areas, comparatively is 8- 10℃ between Beijing city area and outer suburb area in northwestern regions. (ii) The UHI distribution and intensity in daytime are different from nighttime in Beijing city area, the nighttime UHI is obvious. However, in the daytime, the significant UHI mainly appears in the summer, the autumn takes second place, and the UHI in the winter and the spring seem not obvious. The surface evapotranspiration in suburb areas is larger than that in urban areas in the summer, and high latent heat exchange is evident, which leads to LST difference between city area and suburb area. (iii) The reflection of surface landcover categories is sensitive to the UHI, the correlation between vegetation greenness and UHI shows obviously negative.The scatterplot shows that there is the negative correlation between NDVI and LST (R2 = 0.6481).The results demonstrate that the vegetation greenness is an important factor for reducing the UHI,and large-scale construction of greenbelts can considerably reduce the UHI effect.