鄂尔多斯盆地上石炭统—中二叠统砂岩物源分析*

对区域地质、地层接触关系、砂岩组分、重矿物及微量元素等的综合分析与研究结果表明,鄂尔多斯盆地北部上石炭统—中二叠统砂岩的物源区主要为再旋回造山带物源区,并可划分出乌海—银川、杭锦旗—东胜及准格尔旗—府谷3个物源区。受物源分异的影响,盆地内部石英砂岩分布以杭锦旗—东胜为界,具有明显的东西分区性。其中石英砂岩主要分布于盆地西部,古水流、重矿物及砂岩组分指示物源来自阿拉善古陆。而盆地东部总体上是岩屑砂岩的覆盖区,物源主要来自盆地北部和东北部阴山地区。盆地西南部及南部砂岩的物源区为克拉通地块和再旋回造山区,物源区与秦祁造山带的演化关系密切,具有稳定与活动的双重特性,可划分出海原、同心—中宁,平凉—固原、环县及耀县—宜君、富县3个主要物源区。南北物源汇水区在环县—富县—乡宁一带,呈北西西向狭长带状延伸,并从山西期—盒8期呈逐渐南移趋势。盆地西部物源到下石盒子组沉积时期才提供粗碎屑物质补给,以含有较多的长石石英砂岩为特征。周至柳叶河石炭—二叠系砂岩的物源区为再旋回造山带物源区和陆块物源区,为北秦岭造山带内山间盆地,属于盆地外缘,并与鄂尔多斯盆地呈连续过渡的关系。     

准噶尔盆地南缘东段侏罗系—白垩系物源及其演化特征

准噶尔盆地南缘东段侏罗系—白垩系储层油气勘探潜力巨大,但关于其物源条件及沉积背景演化方面的认识较为有限,严重制约了后续油气勘探开发进程。为顺利开展后续油气勘探,笔者应用砂岩碎屑成分、砾岩砾石成分、重矿物类型及组合特征、古水流特征、地层岩性比例特征等物源分析方法,并结合区域构造演化背景,对准噶尔盆地南缘东段侏罗系—白垩系沉积物源特征进行厘定,并恢复其演化过程。研究结果表明：早侏罗世,博格达山尚未隆升,准南东段物源体系受控于北部克拉美丽山及南部天山山体,研究区南部原始沉积边界距现今盆地边界最远;自中侏罗世以来,由于受周缘山体隆升及燕山运动影响,博格达山开始隆升并逐渐出露水面,对准南东段物源体系产生一定影响;自晚侏罗世—早白垩世,博格达山的持续隆升作用使其隆起高度和规模不断增大,并最终成为准南东段优势物源区,克拉美丽山隆起幅度也不断增大,而使其供源能力增强。整体上,早侏罗世—中侏罗世,准南东段受南部天山物源体系和北部克拉美丽山物源体系共同影响;而在中侏罗世—早白垩世这一沉积期,南部天山物源体系、北部克拉美丽山物源体系和博格达山物源体系并存,但各物源体系对准南东段侏罗系—白垩系影响程度存在差异。     

鄂东下二迭统含磷结核层

<正> 湖北省石油化学工业局刘乃富同志报道黄石煤炭矿务局袁仓煤矿,在下二迭统茅口组揭露到含磷泥质、硅质岩层。袁仓矿区茅口组厚162米,含磷层产于茅口组中部,厚2—3.5米。含磷层由硅质泥质物胶结磷结核构成。磷结核黑色、灰黑色,少数为棕色;直径1—5厘米,3—5厘米者居多。以硅质胶结物为主的硅质岩中含磷结核率12.7—25％,厚0.8—1.2米;以泥质胶结物为主的泥质岩中含磷结核率29.5—41.7％,厚1.3—2.3米。磷结核P_2O_5含量22.18—32.7％,含磷泥质硅质岩P_2O_5含量0.88—1.88％。     

有机—铜配合物热稳定性及热分解产物的实验研究

通过实验研究了富里酸、氨基丙酸和半胱氨酸３种有机质与铜的配合物的热稳定性及热分解产物特征。结果表明：富里酸—铜配合物在１９０～２００℃时缩合成类干酪根物质，被富里酸配合的铜一同进入到该物质中去；氨基丙酸—铜配合物在１４０～１５０℃分解，形成π键配合物“二（三）氯·（乙炔）合铜（Ⅰ）”；半胱氨酸—铜配合物很不稳定，８０℃便开始分解，生成黑色沉淀物“二水合四氯合铜酸铵”，而没有生成铜的金属硫化物     

河南南襄盆地泌阳凹陷东南部古近系核桃园组物源分析*

在层序地层格架的基础上,结合区域地质概况和前人研究成果,充分运用重矿物的组合特征、岩心观察描述的岩性序列特征、岩性及电性的横向变化特征、地震反射特征,结合砂岩厚度、砂地比的平面展布规律,对南襄盆地泌阳凹陷东南部古近系渐新统核桃园组的物源方向进行了研究。结果表明,泌阳凹陷东南部主要发育5个物源,其中主要物源有1个,为泌150—泌285井区的平氏物源,该物源对研究目的层各个层序的西南部沉积砂体均有控制;次要物源有4个,即泌102—泌239井区的杨桥物源、正南方向的泌151—泌251井区的魏庄物源、东南方向泌129井区的栗园物源、以及东北方向的泌319井区的栗园东北物源,这些次要物源仅对部分层序的沉积砂体有控制作用。     

河南南襄盆地泌阳凹陷东南部古近系核桃园组物源分析

在层序地层格架的基础上,结合区域地质概况和前人研究成果,充分运用重矿物的组合特征、岩心观察描述的岩性序列特征、岩性及电性的横向变化特征、地震反射特征,结合砂岩厚度、砂地比的平面展布规律,对南襄盆地泌阳凹陷东南部古近系渐新统核桃园组的物源方向进行了研究。结果表明,泌阳凹陷东南部主要发育5个物源,其中主要物源有1个,为泌150—泌285井区的平氏物源,该物源对研究目的层各个层序的西南部沉积砂体均有控制;次要物源有4个,即泌102—泌239井区的杨桥物源、正南方向的泌151—泌251井区的魏庄物源、东南方向泌129井区的栗园物源、以及东北方向的泌319井区的栗园东北物源,这些次要物源仅对部分层序的沉积砂体有控制作用。     

饶阳凹陷新近系馆陶组物源方向分析

为了深入认识沉积物源的位置及古流向,通过矿物成分、岩屑特征、重矿物组合及分布、砂体展布特征等分析,对饶阳凹陷馆陶组的物源方向进行了系统研究。结果表明,饶阳凹陷新近系馆陶组沉积时期,盆地存在4个相对独立的物源及古水流体系:分别为来源于北或北东部物源自北向南或北东—南西流向的水系,来源于西部物源、西南—北东向展布的水系,源于西部物源、东西向展布的水系,源于南部或西南部物源、西南—北东向展布的水系。新近系的河流流向以南北向、沿盆地长轴方向为主,盆地内砂体具有南北向带状展布的特征;中部留路地区距离物源区相对较远、盖层较发育、储盖组合条件好,为饶阳凹陷新近系油气聚集的有利区带。     

水杨基萤光酮-CTMAB荧光猝灭法测定痕量镓的研究

近年来,采用水杨基萤光酮(SAF)与金属离子在表面活性剂存在下形成三元配合物,使试剂SAF荧光猝灭而测定金属离子的方法已有不少报道。但利用Ga—SAF—CTMAB形成三元配合物导致SAF荧光猝灭而测定Ga的方法尚未见报道。我们发现,SAF—CTlWAB体系在400nm处有最     

新疆西昆仑特格里曼苏砂岩型铜矿地质特征及成因探讨

特格里曼苏铜矿产于库山河群(C1k)砂岩中,矿体呈层状、似层状产出,受地层控制,浅色砂岩与紫色砂岩的交互带是铜矿体产出的最有利层位.通过对含矿砂岩胶结物的研究,认为赋矿砂岩中胶结物类型主要有碳酸盐胶结、硅质胶结、泥质胶结和铁质胶结4种,常见的胶结物组合类型有碳酸盐—硅质胶结组合、碳酸盐—泥质胶结组合、硅质—泥质胶结组合、铁质—泥质—碳酸盐胶结组合;矿化常发生于具碳酸盐—硅质胶结组合的砂岩中,铜矿物与硅质胶结物伴生.通过对含矿砂岩胶结物中流体包裹体研究,得到成矿流体为低温、低盐度流体.认为矿床成因为沉积成岩成因,古陆的风化剥蚀提供了基本的成矿物质,沉积物的搬运沉积形成了矿源层,成岩作用时期由于有机质及细菌的作用、氧化还原条件的改变,在成岩流体的迁移下造成了铜质的局部再富集,形成具有工业意义的铜矿体.     

山西某芒硝矿床中硼磷镁石的研究

硼磷镁石(Lueneburgite,)系一种稀少的含水含磷硼酸盐矿物。该矿物1870年发现于德国汉诺威的吕内堡。现已知国外产地有:美国新墨西哥二叠纪含盐盆地,苏联里海的卡拉—博加兹—戈尔海湾及喀尔巴阡的斯捷布尼克等地区。此     

Alteration of a pelagic chalk below a paleokarst surface,Oxford, South Island,New Zealand

A small isolated outlier of Lower Oligocene chalk, which grades upwards into what was originally a sandy marl, has been truncated by a paleokarst surface, which is overlain by cross-bedded, well-sorted glauconitic sands. A sandy clay horizon (probably originally tuffaceous) and a basaltic lava flow of probable Miocene age cap the local sequence. Below the paleokarst surface and roughly parallel to it, the original sediment has been intensely altered to an average depth of 1.5 m. The alteration front is sharply defined, even where it extends along the walls of glauconitic sand-filled fissures in the chalk.In the alteration zone, the chalk has been entirely replaced by silica (opal-CT, largely in the form of lepispheres). The calcareous fraction of the marl has been replaced by montmorillonite and clinoptilolite. Rounded gravel clasts (largely basaltic) in the base of the overlying glauconitic sands also have been replaced (by montmorillonite), which suggests that all alteration followed deposition of the sands. However, neither the glauconite nor any other mineral in the sands appears highly altered. Similarly, the quartz grains show no evidence of dissolution or silica precipitation. Preservation of most silica sponge spicules, the only siliceous microfossils in the chalk, indicates that the source of the silica was extraneous to the carbonate sediments.Migrating interstitial liquid, largely confined to the sands between the impervious cap of sandy clay plus basalt and the porous but less permeable chalk, is inferred to have been the causal agent for the replacement. Silica, and any other components necessary for the formation of opal-CT, montmorillonite and clinoptilolite, were probably derived by chemical alteration of the capping volcanics in a groundwater regimen. Replacement reactions in the chalk and marl presumably were dependent on the original presence of calcium carbonate, and apart from montmorillonitization of volcanic material, occurred only where this compound was present.     

The environmental influence of a volcanic plume,a new technique of study,Mount Etna,sicily

Detailed study of the chemistry of volcanic plumes has previously been hindered by the difficulties of sampling, particularly if data on trace elements are required. In an attempt to overcome this problem, and to learn more about the regional effects of the plume of Mt. Etna, it was decided to investigate whether lichens, which are used as indicators of aerial pollution, would be suitable for this type of study. Samples collected from the slopes of Etna were assayed, mainly for heavy metals. The results show that this technique has great potential, that lichens can be used to determine semiquantitatively the minor and trace element composition of the plume, and can detect the influence of the plume on the chemistry of local rainfall.     

Brussels, a truncated metropolis

This paper describes and analyses the geographical development and the governmental, budget and administrative structure of Brussels. It defines the place Brussels occupies among the cities of Europe and assesses the value of its Regional Development Plan. Brussels appears to be highly successful in international inter-city competition, but it also appears to be unable to develop a strategy for dealing with the problems of the divided city it has become in the late-20th century. Key factors in explaining this paradox are a discrepancy between the political delimitation of the Brussels Capital Region (a member state of the federal state of Belgium) and the geographical urban region, and the administrative fragmentation of the Brussels Capital Region. These factors are strongly related to the reform of the Belgian state and the forces behind this reform. In the absence of a strategy based on solidarity within the metropolitan community, one has to fear for the development towards a repressive city. This revised version was published online in August 2006 with corrections to the Cover Date.     

Petrology of a mantle-derived rhyolite, Hokkaido, Japan

The Miocene Kitami rhyolite, consisting of orthopyroxene and plagioclase-phyric lavas and dikes, occurs on the back-arc side of the Kuril arc with coeval basalts and Fe-rich andesites. Temperatures estimated from orthopyroxene–ilmenite pairs exceed 900°C. Although the whole rock compositions of the Kitami rhyolite correspond to S-type granites (i.e., high K, Al, large ion lithophile elements, and low Ca and Sr), Sr–Nd isotope compositions are remarkably primitive, and similar to those of the coeval basalts and andesites. They are distinct from those of lower crustal metamorphic rocks exposed in the area. Comparison of chondrite-normalized rare earth element (REE) patterns between the rhyolite and the basalts and andesites show that the rhyolite is more light REE enriched, but has similar heavy REE contents than the basalts. All rhyolites show negative Eu anomalies. The geochemical data suggest that did not formed by simple dehydration melting of basaltic rocks or fractional crystallization of basaltic magmas. The features of slab-derived fluids expected from recent high pressure experimental studies indicates that mantle wedge is partly metasomatized with “rhyolitic” materials from subducted slabs; it is more likely that very low degree partial melting of the metasomatized mantle wedge formed the rhyolite magma.     

Evidence for a shock-metamorphic breccia within a buried impact crater,Lake Raeside,Yilgarn Craton,Western Australia

Mineral exploration drilling 60 km west of Leonora in 2008 intersected >95 m of poorly consolidated granitoid-dominated breccia at the base of a Cenozoic paleochannel beneath Lake Raeside. The breccia, initially interpreted as a kimberlite, is composed of poorly consolidated fragments of granitic gneiss, felsite and metamorphosed mafic rock within a matrix of fine to medium-grained breccia. Microscopic examination revealed quartz grains displaying well-developed planar deformation features (PDFs) dominated by the ω? {1013} planar set, diaplectic silica glass and diaplectic plagioclase glass. These features constitute the diagnostic hallmarks of shock metamorphism owing to high-velocity impact of a large meteorite or asteroid. The PDFs in quartz grains of the breccia are distinctly different from metamorphic deformation lamellae produced tectonically or in diatremes. Airborne total magnetic intensity data suggest an outline of an 11 km-diameter crater, consistent with the significant thickness of the shock-metamorphosed breccia at >95 m, suggestive of the existence of a large impact structure.     

Althausite,a new mineral from Modum,Norway

Althausite occurs as cleavable masses in serpentine-magnesite deposits at Modum, Norway. The proposed formula in Mg₂PO₄ (OH_0.37F_0.25O_0.10)_0.81 with partly vacant halide sites. It is orthorhombic, space group Pna2₁, $\text{a}\text{= 8.258,}\text{b}\text{= 14.383,}\text{c}\text{= 6.054}\text{A}\text{?}\text{, Z}\text{= 8.}\text{D(meas)}\text{=2.97, ?(}\text{calc}\text{) = 2.91}\text{g/cm}{}^3\text{(}\text{X-ray}\text{), ?(}\text{calc}\text{) = 3.06}\text{g/cm}{}^3\text{(}\text{Gladstone-Dale}\text{),}\text{H}\text{= 3}\text{1}\text{2}\text{?4.}$ The strongest X-ray powder lines (41 given, FeKα radiation) with intensities and indices are 3.593 (100)(040), 3.316 (90)(211), 3.024 (80)(002), 2.786 (60)(112), 2641 (60)(122).The mineral is light grey with vitreous lustre, running brown on alteration to apatite. Non-fluorescent. Perfect cleavage {001}, distinct cleavage {101}. It is biaxial positive, α=1.588, β=1.592, γ=1.598, 2V_γ(calc)=78.5°, negative elongation, X=b, Y=c, Z=a. IR, DTA and TGA data are given.     

Coral-stromatolite reef framework, Upper Miocene, Almería, Spain

Stromatolitic crusts on stick-like and platy Porites corals forming Messinian reefs in Almería played an important role in supporting and binding the brittle corals. The crusts were previously regarded as probable marine cements. However, their clotted, peloidal, and micritic fabrics are directly comparable with those of stromatolites. They accreted allochthonous grains even on vertical faces, and include bushy fabrics closely comparable with those produced by cyanobacterial calcification. They contain numerous fenestrae, exhibit rapid fabric variation, and locally form micro-columns and laminated domes. Their similarities to peloid micrite crusts in Recent reefs suggest that at least some of these Recent crusts are microbial in origin, even though they have widely been interpreted as marine cements. The sedimentary effects of crust development substantially affected both the morphology and relief of the reefs and the generation of reefal clasts. Binding of the reef-frame in the Pinnacle and Thicket zones in the lower and middle parts of the reef created a rigid margin which shed large (commonly up to 5 m) cuboidal blocks of coral-stromatolite frame. The blocks broke along planes of weakness provided by the vertical Porites sticks and were deposited on the Fore-Reef Slope. In the uppermost parts of the reefs crusts dominate the structure, constituting 80% or more of the rock. Veneers up to 15 cm thick encrust thin irregular Porites plates to create a solid Reef Crest Zone which has not been recognized before. The coral-stromatolite framework is associated with echinoids, crustose corallines and halimedacean algae which, together with the scleractinians, indicate normal marine salinity throughout reef growth.     

翼龙重建：方法论的一个研究例子

Reconstructions of fossil animals are widespread and often very high profile, yet many of these reconstructions exhibit low standards of scientific accuracy.