萨拉乌苏河流域第四系岩石地层及其时间界限

根据对位于鄂尔多斯高原毛乌素沙漠东南部边缘萨拉乌苏河流域的米浪沟湾剖面岩石地层划分并结合年代测试结果,提出了如下一些看法1以组为代表的岩石地层单元的形成时间为离石组>150000aB.P.、萨拉乌苏组150000-75000aB.P.、城川组75000-10000aB.P.、大沟湾组-滴哨沟湾组10000-1000aB.P.、范家沟湾组1000aB.P.-现代.2以上岩石单元与黄土高原相同时期层系具有较好的对比关系离石组\萨拉乌苏组、萨拉乌苏组\城川组和城川组\大沟湾组在地质时代上依次与L₂\S₁(时限为140000aB.P.)、S1\L1(时限为80000aB.P.)和L1\S0(时限为11000-10000aB.P.)大体是等时的.3如以过去全球变化而论,则目前已经可以确切地将米浪沟湾剖面诸岩石单元与深海和大陆冰川最近地质时期的若干氧同位素阶段进行对比,以“”表示为离石组MIS6、萨拉乌苏组MIS5、城川组MIS2～MIS4、大沟湾组+滴哨沟湾组+范家沟湾组MIS1.显然,这一对比关系清楚地说明,我国沙漠万年时间尺度环境演变,与黄土的研究结果一样,在很大程度上受到北半球冰期间冰期气候波动的影响.据此,可以按气候地层进行划分,将离石组、萨拉乌苏组、城川组、大沟湾组+滴哨沟湾组+范家沟湾组的时代分别置于里斯冰期、里斯-玉木间冰期(末次间冰期)、玉木冰期(末次冰期)和冰后期。     

长江中下游马头斑岩型钼铜矿床常量元素、稀土元素特征及迁移规律研究

安徽马头钼铜矿是长江中下游成矿带中斑岩型矿床的典型代表,矿床在空间上划分出了3个不同的蚀变分带,即钾长石化带、石英-绢云母化带和青磐岩化带.本文对该矿床不同蚀变带内的常量元素迁移规律和稀土元素特征进行了探讨:①常量元素的迁移规律明显,从钾长石化带和石英-绢云母化带到青磐岩化带,均为带入的主要成分有K2O、CaO、Fe2O3、SiO2、H2O+,说明引起蚀变的流体中富含K2O、CaO等;而Na2O、FeO、MnO等成分的明显带出,说明矿化蚀变作用导致Na2O、FeO等成分向矿体迁移方向流失,其中Na2O的贫化最明显,与成矿元素Mo、Cu呈显著的负相关.②马头钼铜矿床花岗闪长斑岩的稀土配分模式图表现为左高右低的较平滑曲线,轻稀土富集,重稀土亏损.稀土元素的质量迁移计算结果同样证明了稀土元素在矿化蚀变过程中发生了分馏,且从钾长石化带到青磐岩化带,稀土元素带出量呈递增趋势.③该矿床样品的稀土元素配分特征表明,较新鲜花岗闪长斑岩与蚀变围岩的曲线基本相同,表明成矿物质主要来自花岗闪长岩熔体,并且可能有海水的混入.由δEu、δCe值及Fe2O3与FeO带出带入的关系可知,斑岩流体晚期氧逸度逐渐升高,表明成矿环境可能由相对还原过渡到氧化环境.④除Al2O3、TiO2保持惰性外,常量元素、稀土元素在矿化蚀变过程中都发生不同程度的带入带出,富集贫化特征和迁移规律不完全相同.     

新疆阿克陶县塔木-卡兰古铅锌矿带矿床地质和硫同位素特征

新疆塔木—卡兰古铅锌矿带位于塔里木板块西南缘之晚古生代碳酸盐台地环境中。矿化以铅锌矿为主 ,个别矿床含铜。矿床赋存于中泥盆统—下石炭统三个控矿的古含水层中 ,矿体形态复杂 ,富矿段往往赋存于多组断裂构造交汇部位。矿石根据其结构大体可分两类 :一类呈角砾状构造 ,硫化物呈浸染状 ,共 (伴 )生赤铁矿和磁铁矿 ;另一类矿石中硫化物以胶状、草莓状结构为主。硫化物硫同位素值具有较宽的范围 ,δ3 4 S为 - 39.2‰～ 14‰ ,主要集中在 - 2 9.3‰～- 17.7‰和 - 3.6‰～ 5 .1‰两个区间 ,分别与上述两类矿石相对应。研究表明 ,位于泥盆系与石炭系间的第二古含水层是最重要的找矿层位 ,角砾岩带是重要的找矿评价标志 ,矿床成因可能属密西西比河谷型 (MVT) ,两种性质差异很大的低温热液混合引起成矿物质的沉淀和成矿     

Gold Mineralization in Kottathara Prospect, Attappadi Valley, Kerala, India: a Preliminary Appraisal

The Kottathara gold prospect of Attappadi Valley in Kerala is located within the Southern Indian Granulite Terrain comprising charnockite and gneisses with enclaves of high-grade supracrustals. The gold mineralization associated with the basic members of the Attappadi supracrustals and the quartz veins traversing them are confined within the Bhavani Shear Zone. Primarily the gold-quartz lode is emplaced in rheologically preferred zones along the contact of the basic members with the enclosing gneisses subsequent to a period of retrogression and shearing. Ore-mineralogical studies reveal that gold got remobilized and this remobilization is identified with the regional Bhavani Shear. SEM studies indicate that gold occurs in free state and also within sulphides especially pyrite. Variation in grain morphology is clearly discernible in gold occurring within oxidised and in non-oxidised zones.Sequencing of deformational events with associated emplacements of known ages suggests the age of gold mineralization of Attappadi area as between 2 Ga. and 2.5 Ga. The secondary mobilization has to be <2.0 Ga or younger possibly of younger Pan-African age related with the Moyar-Bhavani Shear System. The inherent gold content of the komatiitic metapyroxenites together with the auriferous quartz lodes assigns a lithological control on gold mineralisation. Subsequent folding and remobilization due to the regional shear constrained the geometry of the lode zones implying structural control.     

现代旅游者意念中的夜郎形象及其构筑刍议

古夜郎国植根于喀斯特环境.本文从广义夜郎的角度出发,采用随机抽样调查法对旅游者进行调查,用SPSS软件进行统计,从吃、住、行、游、购、娱几个方面来分析现代旅游者对夜郎文化的旅游需求;选择贵阳市花溪区的夜郎谷风景旅游区来构筑现代旅游者意念中的夜郎形象.最后以"夜郎传说再现"、"夜郎生活活的博物馆"和"其它功能区"为主题,将夜郎谷旅游景点构筑为水面娱乐区、展览区、竹文化区、农耕区、作坊区、图腾柱景观区、夜郎石魂区、雕刻展卖区、野营区、夜郎生活演示区、表演区、乡村旅店区、游憩区、艺术石廊等14个功能区,同时结合夜郎谷周围的资源特点构筑夜郎文化旅游圈.     

从含油气系统到成藏油气系统——油气系统研究新动向

针对不同研究重点,油气系统理论的形成经历了三个重要发展阶段：含油气系统阶段、复合含油气系统阶段和成藏油气系统阶段。这个发展过程是一个从简单到复杂、从“源控”到“藏控”的发展过程,也是一个指导油气勘探从粗放到精确的认识过程。以油气藏为研究中心、侧重于油气运移和成藏的成藏油气系统的提出使我们对油气藏的刻画更为精确、定位更为准确,并为油气勘探走向精确勘探奠定了一个重要的思想基础。油气系统概念是油气地质研究中的一种系统化的思想,它的最大意义在于告诉我们怎样用系统化的思想研究复杂的油气成藏问题。     

伊犁河谷不同植被带下土壤有机碳分布

结合2008年和2009年野外实地调查与室内分析的资料,运用方差分析等方法对伊犁河谷高山草甸、草甸草原、典型草原、荒漠草原、温性针叶林等9种不同植被条件下的土壤有机碳含量分布及其储量进行了分析估算.研究结果表明:伊犁河谷土壤有机碳含量因植被类型变化而不同.在0～50 cm土层范围,高山草甸、草甸草原土壤有机碳含量较高,其次是温性针叶林和典型草原,含量最低的是隐域植被和荒漠植被土壤.除隐域植被外,各植被类型下土壤有机碳含最基本呈随着土层深度增加而降低的,变化趋势.有机碳密度同样是高山草甸、草甸草原和温性针叶林土壤有机碳密度较高且比较相近,荒漠植被下土壤有机碳密度最低.伊犁河谷草地表层土壤有机碳含量高、密度大,因此应重视对伊犁河谷草地的保护,尤其要保护草地表层土壤以降低浅层土壤有机碳发生变化的可能性,维护土壤碳库的稳定性.     

Characters of Nummulites multiplicutiospiralis n. sp. from theQarara Formation,Maghagha, Nile Valley,Egypt

Nummulites multiplicutiospiralis n.sp.is described and illustrated for both generations from a claystone of Lutetian age in the Middle Eocene Qarara Formation, Maghagha,Nile valley,Egypt.Previously considered to be Nummulites gizehensis,we describe this form as a new species based on diameter of the test and protoconch sizes,septal shape and granulations.The primary feature of this species is spiral multiplication,seen in spiral section.The species is also characterized morphologically by lenticular to flat tests with rounded periphery,wrinkled to broadly meandering septal filaments and few granules on the periphery in microspheric forms.The granules are spirally arranged on the septal filaments in megalospheric forms.Chambers are longer than high and the spire is irregular.The new taxon belongs to the Nummulites partschi Group,Subgroup N.gizehensis.Reflexive coiling in the spiral may develop through ontogeny as in N.rollandi,the species which was considered to be an index species in the southern Tethys (Boukhary et al.,1982 and Boukhary et al.2010).The characters of the new species,as well as its retrogenesis and reflexive coiling,should be further studied in general in Nummulites spp.,to understand the importance of such characters phylogenetically.     

热带副热带高度异常对长江流域和华北旱涝影响的数值模拟与分析

前期南亚高压的异常增强或者减弱,热带、副热带地区100 hPa高度的异常增高或者降低,热带西风的异常增强或者减弱,对长江流域和华北地区夏季的降水异常具有预示作用。文中设计了一系列的数值试验进行模拟研究,包括控制试验、敏感试验和4组合成试验。合成试验模拟结果表明,前期热带、副热带高度异常分布,能够再现长江流域、华北旱涝情况。前期南亚高压、热带、副热带高度、风异常对长江流域和华北地区夏季降水的异常均有预示作用。100 hPa叠加高度、风异常的敏感试验结果表明:前期南亚高压、热带与副热带地区100 hPa高度场和环流场的异常不仅可以预示、事实上能够引起长江流域和华北夏季降水的异常———前期南亚高压异常增强、热带、副热带地区100 hPa高度场异常增高、西风异常增强,易引起长江流域降水偏多、华北降水偏少;反之,则容易引起长江流域降水偏少、华北降水偏多。     

Relationship between the Late Spring NAO and Summer Extreme Precipitation Frequency in the Middle and Lower Reaches of the Yangtze River

The relationship between the late spring North Atlantic Oscillation (NAO) and the summer extreme precipitation frequency (EPF) in the middle and lower reaches of the Yangtze River Valley (MLYRV) is examined using an NECP/NCAR reanalysis dataset and daily precipitation data from 74 stations in the MLYRV. The results show a significant negative correlation between the May NAO index and the EPF over the MLYRV in the subsequent summer. In positive EPF index years, the East Asian westerly jet shifts farther southward, and two blocking high positive anomalies appear over the Sea of Okhotsk and the Ural Mountains. These anomalies are favorable to the cold air from the mid-high latitudes invading the Yangtze River Valley (YRV). The moisture convergence and the ascending motion dominate the MLYRV. The above patterns are reversed in negative EPF index years. A wave train pattern that originates from the North Atlantic extends eastward to the Mediterranean and then moves to the Tibetan Plateau and from there to the YRV, which is an important link in the May NAO and the summer extreme precipitation in the MLYRV. The wave train may be aroused by the tripole pattern of the SST, which can explain why the May NAO affects the summer EPF in the MLYRV.