滇中易门地区发现化石新物种

通过1:50 000区域地质调查,在滇中易门地区前人划分的中元古界东川群鹅头厂组灰黑色炭泥质板岩中首次发现了大量保存较好的宏体多细胞生物化石。通过镜下分析、电子探针及电镜扫描的研究,确证其是迄今为止生物结构最为完整的个体较大的多细胞宏体生物化石,填补了云南境内前寒武纪地层无生物化石的空白,宏体生物化石的发现有重大的科学意义及科研价值,是地球早期生命演化研究领域中一项重大的科学发现对地球早期地球环境演化与生命进化的研究具有重要价值。     

“三江”地区北段区域地球化学元素组合异常提取及其找矿意义

由于地球化学元素携带了某种矿化信息,因此元素地球化学异常往往是指示矿床存在的一种直接标志。随着勘查地球化学的深入发展,有关矿致地球化学异常圈定方法已成为人们关注的焦点。利用"三江"北段1∶20万地球化学数据,运用R型因子分析,查明该区不同矿化类型的指示元素组合,以因子得分为综合指标,采用泛克里格剩余值圈定地球化学异常。结果得到2种元素组合:Ag-Zn-Pb-Sb-Bi组合(与热液型铅锌银矿床有关)和Mo-Cu组合(与斑岩型钼矿床有关)。圈定的组合异常与已知的矿床点在空间上具有很好的对应关系,说明利用R型因子分析与泛克里格法相结合圈定元素组合异常的方法能够较好地确认地球化学元素组合异常,并提示异常与矿化类型之间密切相关的规律性,为"三江"北段地区找矿提供信息。     

Effect of cadmium on the defense response of Pacific oyster Crassostrea gigas to Listonella anguillarum challenge

Heavy metal pollution can affect the immune capability of organisms.We evaluated the effect of cadmium(Cd) on the defense responses of the Pacific oyster Crassostrea gigas to Listonella anguillarum challenge.The activities of several important defensive enzymes,including superoxide dismutase(SOD),glutathione peroxidase(GPx),acid phosphatase(ACP),Na+,K+-ATPase in gills and hepatopancreas,and phenoloxidase-like(POL) enzyme in hemolymph were assayed.In addition,the expression levels of several genes,including heat shock protein 90(HSP90),metallothionein(MT),and bactericidal/permeability increasing(BPI) protein were quantified by fluorescent quantitative PCR.The enzyme activities of SOD,ACP,POL,and GPx in hepatopancreas,and the expression of HSP90 were down-regulated,whereas GPx activity in the gill,Na+,K+-ATPase activities in both tissues,and MT expression was increased in Cdexposed oysters post L.anguillarum challenge.However,BPI expression was not significantly altered by co-stress of L.anguillarum infection and cadmium exposure.Our results suggest that cadmium exposure alters the oysters’ immune responses and energy metabolism following vibrio infection.     

油气成藏动力学研究方法与应用

油气成藏过程的动力学研究是以一期油气成藏过程中从油气源到油气藏的统一动力环境系统为单元,定量研究油气供源、运移、聚集的机理、控制因素和动力学过程。以此为基础有望解决油气成藏定量的动力学研究中的几个关键问题。输导层概念的提出及砂岩输导层模型基本工作程序的建立,形成了可以利用通常的物性参数进行输导层量化表征的方法,实现了对油气运移通道的量化表征; 采用断层连通概率的概念对各种参数表征断层开启性的能力进行比较和评价,探讨了各种地质参数的有效性和代表性,建立起了断层启闭性表征参数的评价方法; 采用数值模拟方法,耦合运聚动力与输导体系,实现成藏系统内油气运移过程的模拟分析; 以运移途中烃损失量估算为基础,建立新的物质平衡方法,以模拟获得的运移路径为线索,评估油气在研究不同方向上的运移聚集量,展现油气运移的路径特征、运移方向及运移量,初步形成了以油气成藏动力学成因为基础的油气资源预测方法。     

秦安县农村居民点空间分布景观格局分析

基于RS与GIS技术,以2008年甘肃省秦安县SPOT遥感影像为数据源,主要选职斑块面积、斑块数、平均斑块面积、斑块大小变异系数、斑块大小标准偏差、平均形状指数、平均周长．面积比、平均斑块分维数8个景观指数,从居民点用地、规模、形态、分布等方面进行景观空间格局分析。结果表明：秦安县农村居民点分布特点受坡度、坡向、高程、...     

滇西腾冲地块东南缘早白垩世火山岩锆石U-Pb定年及地质意义

滇西腾冲地块东侧高黎贡变质岩带,发育一套浅变质的沉积岩地层,其时代不明。本次1:5万区域地质调查在潞西市轩岗乡团坡地层剖面中,确定了该套地层含有酸性火山岩夹层,获得火山岩的锆石U-Pb年龄为121.4±1.4Ma。这一结果表明该套地层的时代为早白垩世;同时也揭示研究区存在早白垩世火山活动,其成因可能与怒江洋盆的闭合有关。     

Petrogenesis of garnet-bearing ultramafic rocks and associated eclogites in the Su-Lu ultrahigh-P metamorphic terrane, eastern China

Ultramafic blocks that themselves contain eclogite lenses in the Triassic Su-Lu ultrahigh-P terrane of eastern China range in size from hundreds of metres to kilometres. The ultramafic blocks are enclosed in quartzofeldspathic gneiss of early Proterozoic age. Ultramafic rocks include garnetiferous lherzolite, wehrlite, pyroxenite, and hornblende peridotite. Garnet lherzolites are relatively depleted in Al₂O₃ (<3.8wt%), CaO (<3.2%) and TiO₂ (<0.11 wt%), and are low in total REE contents (several p.p.m.), suggesting that the rocks are residual mantle material that was subjected to low degrees of partial melting. The eclogite lenses or layers within the ultramafic rocks are characterized by higher MgO and CaO, lower Al₂O₃ and TiO₂ contents, and a higher CaO/Al₂O₃ ratio compared to eclogites enclosed in the quartzofeldspathic gneiss. Scatter in the plots of major and trace elements vs. MgO, REE patterns and La, Sm and Lu contents suggest that some eclogites were derived from melts formed by various degrees (0.05–0.20) of partial melting of peridotite, and that other eclogites formed by accumulation of garnet and clinopyroxene ± trapped melt in the upper mantle. Both ultramafic and eclogitic rocks have experienced a complex metamorphic history. At least six stages of recrystallization occurred in the ultramafic rocks based on an analysis of reaction textures and mineral compositions. Stage I is a high temperature protolith assemblage of Ol + Opx + Cpx + Spl. Stage II consists of the ultrahigh-pressure assemblage Ol + Cpx + Opx + Grt. Stage III is manifested by the appearance of fine-grained garnet after coarse-grained garnet. Stage IV is characterized by formation of kelyphitic rims of fibrous Opx and Cpx around garnet, and replacement of garnet by spinel and pargasitic-hornblende. Stage V is represented by the assemblage Ol + Opx + Prg-Hbl + Spl. The mineral assemblages of stages VI_A and VI_B are Ol + Tr-Amp + Chl and Serp + Chl ± talc, respectively. Garnet and orthopyroxene all show a decrease in MgO with retrogressive recrystallization and Na₂O in clinopyroxene also decreases throughout this history. Eclogites enclosed within ultramafic blocks consist of Grt + Omp + Rt ± Qtz ± Phn. A few quartz-bearing eclogites contain rounded and oval inclusion of polycrystalline quartz aggregates after coesite in garnet and omphacite. Minor retrograde features include thin symplectic rims or secondary amphiboles after Cpx, and ilmenite after rutile. P-T estimates indicate that the ultrahigh-metamorphism (stage II) of ultramafic rocks occurred at 820-900d? C and 36-41 kbar and that peak metamorphism of eclogites occurred at 730-900d? C and >28 kbar. Consonant with earlier plate tectonic models, we suggest that these rocks were underplated at the base of the continental crust. The rocks then underwent ultrahigh-pressure metamorphism and were tectonically emplaced into thickened continental crust during the Triassic collision between the Sino-Korean and Yangtze cratons.     

Re-examination on The Contribution of Deep Thermogenic Gas to Shallow Hydrate in The Shenhu Area, Northern Continental Slope of South China Sea

<正>1 Introduction*In April-June of 2007,the Expedition GMGS-1 was completed successfully in the Shenhu Area of the South China Sea.Gas hydrate was detected at three(Sites SH2,SH3 and SH7)of the five sites that were cored.The Shenhu gas hydrate drilling area is located in the central Baiyun     

世界铼资源供需现状及展望

铼在地壳中的丰度低且分散,多伴生于钨钼矿中,现有方法常采用碱熔富集,流程长且繁琐,亟需开发一种简便快捷的检测方法。本文建立了逆王水微波消解钨钼矿石样品,8-羟基喹啉沉淀分离钨钼元素,与电感耦合等离子体质谱联用的检测方法。结果表明：0.0500g样品,2.80mL逆王水即可实现铼元素的全部溶出,0.20mL有机沉淀剂8-羟基喹啉（3%）在乙酸-乙酸铵缓冲体系（pH 4.5）中可选择性沉淀钼、钨元素,有效消除基体元素钼、钨（沉淀率>95%）对Re定量干扰,同时不引入新干扰元素。相比现有分离富集前处理流程更加简便快捷,前处理时间缩短为现有方法的1/4;该方法对Re的检出限为6.9ng/g,采用国家一级标准物质钼矿石（GBW07238）、钼矿石（GBW07285）、铼钼矿石（GBW07373）和钨锡铋矿石（GBW07369）对方法的准确度进行了验证,测定值与推荐值吻合,相对误差为0.71%～6.07%,RSD＜5%。本方法建立的“消解-分离富集”处理流程所需时间从常规的8～12h缩短至2h左右,在准确定量矿石样品中Re的同时简化了样品前处理流程,快速的样品处理及低廉的测试成本有助于关键稀有金属矿产的开发利用。

     

广播星历和精密星历解算GPS基线成果的比较分析

本文对长度不同的基线分别使用广播星历和精密星历进行解算,分析了两种星历对基线解算结果的影响.通过对解算结果的比较得到使用广播星历的最佳基线长度范围,结果表明,对于长度小于100km的短基线而言,广播星历能够达到与精密星历同样的效果.