中国如何面对石油短缺的挑战--向西部和海洋进军

随着我国经济的高速发展,从1993年起,我国已从石油出口国变成石油纯进口国,2000年进口量达到了7000万吨,几乎占我国当年原油生产总量的44％。目前,我国石油消费量列世界第三位(1.65亿吨),预计未来10年我国石油消费年均增长速度为5％,增速居世界首位。由此可见,石油“血液”在整个国民经济命脉中的不足     

Chemistry of some Pb-(Cu,Fe)-(Sb,Bi sulfosalts from France and Portugal. Implications for the crystal chemistry of lead sulfosalts in the Cu-poor part of the Pb2S2-Cu2S-Sb2S3-Bi2-Bi2S3 system

Electron microprobe analysis of Pb-Cu(Fe)-Sb-Bi sulfosalts from Bazoges and Les Chalanches (France), and Pedra Luz (Portugal), give new data about (Bi, Sb) solid-solution and incorporation of the minor elements Cu, Fe or Ag in jaskolskiite, and in izoklakeite-giessenite and kobellite-tintinaite series. Jaskolskiite from Pedra Luz has high Sb contents (from 17.9 to 20.7 wt.%), leading to the extended general formula: Cu _x Pb_2+x (Sb_1–y Bi _y )_2–x S₅, with 0.10 x 0.22 and 0.19 y 0.41. Fe-free, Bi-rich izoklakeite from Bazoges has high Ag contents (up to 2.2 wt. %), leading to the simplified formula Cu₂Pb₂₂Ag₂(Bi, Sb)₂₂S₅₇; in Les Chalanches it contains less Ag content (1.2 wt.%), but has an excess of Cu that gives the formula: Cu_2.00 (Cu_0.49Ag_1.18)_=1.67Pb_22.70(Bi_12.63Sb_8.99)_=21.62S_57.27.In tintinaite from Pedra Luz, the variation of the Fe/Cu ratio can be explained by the substitution: Cu + (Bi, Sb) Fe + Pb; Fe-free kobellite from Les Chalanches has a Cu-excess, corresponding to the formula Cu_2.81Ag_0.54Pb_9.88(Bi_10.37Sb_5.21)_=15.38S_35.09. Eclarite from the type locality, structurally related to kobellite, shows a Cu excess too. In natural samples of the kobellite homologous series, Fe is positively correlated with Pb, and its contents never exceed that of Cu. Ag substitutes for Pb, together with (Bi, Sb). Taking into account the possibility of Cu excess, but excluding formal Cu²⁺ and Fe³⁺, general formulae can be written:     

Wittite with Se-rich Cosalite and Bismuthinite from Nevskoe Tin Deposit (Magadan District,Russia)

Summary A second confirmed occurrence of wittite, one of the four known Pb-Bi-Se-sulfosalts, has been found in the Nevskoe tin deposit (Eastern Siberia). Microprobe analyses of wittite show pronounced variation of Se content (from 9.5 to 16.5 wt. %), due to S --> Se substitution; Pb and Bi contents vary from 29 and 43%, up to 34 and 46%, respectively. Minor elements are also present: Sb up to 1.5%, Ag up to 1.3 %, and Cu (0 to 0.2%). Comparison of microprobe data of wittite from Nevskoe and Falun, on the one hand, and cannizzarite from different deposits on the other hand, indicate that Ag is incorporated in the wittite/cannizzarite structure through the substitution 2 Pb -> Bi + Ag. Conversely, Ag substraction gives a constant Bi/(Bi + Pb) atomic ratio, independent of the Se/(Se+"S) ratio, and close to 55.1%. Se-rich wittite is compositionally very close to proudite and weibullite. X-ray powder and electron microdiffraction patterns are given; the incommensurate structure agrees with the 7H/12Q match along , like in wittite from Falun. Nevskoe wittite is close to Pb₈Bi₁₀(S, Se)₂₃, but the 7H/12Q match requires the formula Pb_11.61Bi_14.26S₃₃, with about 3% of the Pb atoms in the Q layer replaced by Bi atoms and vacancies (p). Taking into account all microprobe data, the general formula developed is: Pb_{11.61–2x0.13}Ag_x(Bi_14.26+x-ySb_y)(S_1–zSe_z)₃₃ with x and y 0.86 at., and z 0.45. At Nevskoe, associated bismuthinite contains from 5 to 12% Se, with minor Sb, Pb and Cu. Se-rich cosalite contains from 4 to 8% Se, with Sb from 2.7 to 5.3%, and minor Ag and Cu. Wittite in contact with cosalite clearly shows a relative Se-enrichment, that could be due to the pseudo-hexagonal sub-lattice of this incommensurate structure, very similar to the Bi₂(Se, Te, S)3 sheet in the tetradymite series. According to microprobe data, there is a continuous change from Se-free cannizzarite to Se-rich wittite. Therefore, the validity of wittite as a specific mineral species appears questionable, and more accurate crystallographic studies on this incommensurate series are necessary.

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Wittite avec Cosalite et Bismuthinite Séléniferes du Gisement d'Etain de Hevskoe (District de Magadan, Russie)

Resume Une seconde occurrence de wittite, l'un des quatre sulfosels de Pb-Bi-Se cormus, a été trouvée daps le gisement d'étain de Nevskoe (Sibérie Orientale). Son analyse á la microsonde électronique montre une forte variation de la teneur en sélénium (de 9,5 á 16,5%), qui se substitue au soufre; les teneurs en Pb et Bi varient de 29 à 43 et 34 á 46%, respectivement. On note la présence de Sb (, 1,5%), Ag ( 1,3%) et Cu (< 0,2%). La comparaison des analyses de wittite de Nevskoe et Falun, et de cannizzarite de différents gisements, montre que Bans cette série l'argent est incorporé suivant la substitution 2 Pb Bi + Ag. Après soustraction de Ag, le rapport atornique Bi/(Bi + Pb) corrigé apparaït constant, proche de 55,1%, et indépendant du rapport Se/(S + Se). La wittite la plus riche en Se est chimiquement très proche de la proudite et de la weibullite. Son diagramme de poudre aux rayons X ainsi que son étude en microdiffraction électronique sont présentés; la structure, de type incommensurable, s'accorde aver un ajustement selon le rapport 7H/12Q suivant , comme dans la wittite de Falun. La formule de la wittite de Nevskoe est proche de Pb₈Bi₁₀(S, Se)₂₃, mais l'ajustement 7H/12Q demande la formule Pb_11.61Bi_14.26S₃₃, avec environ 3% des sites à Pb du feuillet Q remplacés par des atomes de Bi et des sites vacants (). La prise en compte de l'ensemble des analyses conduit á la formule développée générale: Pb_11.61-2x0.13Ag_x(Bi_14,26+x–ySb_y)-(S_{1 –z}Se_z)₃₃ avec x et y 0,86 at., et z 0,45. A Nevskoe, la bismuthinite associée contient de 5 à 12% Se, avec Sb, Pb et Cu mineurs. La cosalite contient de 4 a 8% Se, 2,7 á 5,3% Sb, avec Ag et Cu mineurs. Lá où wittite et cosalite sont en contact étroit, la wittite montre clairement un enrichissement relatif en Se, qui pourrait etre du au sousréseau pseudo-hexagonal de cette structure incommensurable, très proche du feuillet Bi₂(Se, Te, S)3 présent dans la série de la tétradymite. Les analyses à la microsonde indiquant une continuité chimique de la cannizzarite sans Se à la wittite 1a plus riche en Se, la validité de la wittite en tant qu'espéce spécifique apparaït discutable. Mais le caractère incommensurable de cette série demande une etude cristallographique plus détaillée.

     

Palaeozoic oolitic ironstone of the French Armorican Massif: a chemical and structural trap for orogenic base metal–As–Sb–Au mineralisation during Hercynian strike-slip deformation

In the Saint-Aubin-des-Chateaux quarry (Armorican Hercynian belt, western France), an epigenetic hydrothermal alteration affects an oolitic ironstone layer intercalated within the Lower Ordovician Grès armoricain Formation. The hydrothermal overprint produced pervasive and massive sulphidation with stratoid pyritised lenticular bodies within the oolitic ironstone layer. These sulphide lenses are spatially associated with strike-slip faults and extend laterally from them. After the massive sulphidation stage (Fe–As, stage 1), subsequent fracturing allowed the deposition of base metals (stage 2) and Pb–Sb–Au (stage 3) parageneses in veins. The dominant brittle structures are vertical extension veins, conjugate shear veins and strike-slip faults of various orders. All these structures are filled with the same paragenetic sequence. Deformation analysis allows the identification of structures that developed incrementally via right-lateral simple shear compatible with bulk strain affecting the Central Armorican Domain. Each increment corresponds to a fracture set filled with specific parageneses. Successive hydrothermal pulses reflect clockwise rotation of the horizontal shortening direction. Geothermometry on chlorite and arsenopyrite shows an input of hot hydrothermal fluids (maximum of 390–350°C) during the main sulphide stage 1. The subsequent stages present a marked temperature drop (300–275°C). Lead isotopes suggest that the lead source is similar for all hydrothermal stages and corresponds to the underlying Neo-Proterozoic basement. Lead isotope data, relative ages of deformation and comparison with neighbouring deposits suggest that large-scale fluid pulses occurred during the whole Hercynian orogeny rather than pulses restricted to the late Hercynian period. The vicinity of the Hercynian internal domain appears as a key control for deformation and fluid flow in the oolitic ironstones, which acted as a chemical and structural trap for the hydrothermal fluids. The epigenetic mineralisation of Saint-Aubin-des-Chateaux appears to be very similar to epigenetic sulphidation described in banded iron formation-hosted gold deposits.     

山西代县震群序列特征及其指示意义

2006年4月3日至9月19日在山西代县发生一次3.7级震群,着重研究该震群活动的时序列特征、韵律特征及震源机制解等相关参数。进一步探讨其对周围地区中强震的指示意义。分析结果表明,此次震群活动是该区域一次正常的地震起伏,并与周围350 km范围内华北地区中强震有较好的呼应关系。     

南海北缘早-中更新世之交新构造活动 及其区域对比*

文章根据一系列野外调查和年代测定以及地球化学与地球物理测试分析,阐述了南海北部早更新世湛江组和中更新世北海组的沉积相、化学组分、磁化率等特征,并描述了该区构造变形、褶皱、断裂和火山活动特点。研究结果表明,本区在0.9~0.7MaB.P.的早-中更新世转换期间(中国第三大构造-地貌阶梯主隆起期)发生了一系列构造活动,导致了沉积相由海陆交互相向陆相的转变、大陆风化和剥蚀作用的增强、海平面急剧下降、火山强烈喷发以及褶皱、断裂和不整合面的形成。这种事件群发性所指示的构造活化与中国大陆其他地区的记录相似,例如,黄土高原、青藏高原、华北、华东和西部;同时指示,青藏高原的阶段性隆升不仅导致其自身构造-地貌-气候的剧变,而且引起了周边地区乃至中国和东亚大陆环境的剧变。这种构造运动可能是在气候-构造旋回的规律下,受气候-构造耦合系统的控制,即受内外动力系统的控制,或全球构造系统和全球气候系统的控制。     

点源理论目标的概念和应用

从认识世界对地观测的本源出发，提出了空间信息的理论目标的概念模型——点源系统(PRS)，其根据综合信息场观点和离散目标观点来认识和处理原始混合的对地观测图像信息(RGIS)，可以根据不同尺度的点源，获取具有明确边界和位置属性的目标物体信息。并实现了该模型的几个应用工具——点源尺度变化模型、点源检索模型、点源位模型，完成海量数据信息提取和信息处理直至形成信息库存贮和检索的过程。     

塔什库尔干碱性杂岩体形成时代及其地质意义

帕米尔构造结是青藏高原变形最强烈的地区之一，区内新生代岩浆侵入活动发育，既有壳源岩浆侵位，也有幔源岩浆广泛分布。根据岩石学和地球化学研究，侵入岩可分为幔源碱性正长岩和壳源花岗岩2个系列。幔源碱性正长岩总体上由暗色正长岩、浅色正长岩和碱性花岗岩组成，其成因为岩浆不不混溶作用。壳源花岗岩类成分单一，具有低共熔岩浆属性，其成因可能与幔源岩浆对地壳加热有关。利用碱性正长岩的钾长石进行^40Ar-^39Ar法获得3个分别为大约23Ma、13Ma和8Ma坪年龄数据，结合岩体地质特征，认为它们分别代表了碱性正长岩和花岗岩的侵位时间以及后期构造热事件。研究结果表明，岩浆活动是帕米尔构造结形成和帕米尔强烈变形的主要因素之一。     

油藏储层的岩石磁学描述

油气田勘探中已取得了海量的岩屑,其所蕴含的地质信息有待再利用.岩石磁学在辽河油田储层描述中的应用已取得了成果.在辽河油田曙光潜山,对3口油井的岩屑磁性进行了研究,发现碳酸盐岩储层中含油层位具有较低的磁化率特征,通过井间的磁化率曲线可以较精细地进行地层岩性层位的划分与对比.在辽河油田大民屯凹陷静西陡坡带,沙河街组储层碎屑岩磁化率与总孔隙度、有效孔隙度、泥质含量间具有相关关系;重砂矿物分析表明,在强水动力条件下形成的沉积岩以碎屑岩为主,具有较高的磁化率,其储层性质较好;弱水动力环境下形成的泥质岩磁化率较低,储层性质较差.8口井1009件岩屑磁性数据对该区进行了剖面的、平面的储层性质的岩石磁学描述.两个地区的例子说明,岩石磁学在油藏储层描述中具有极大的潜力.     

新疆哈尔里克双峰山浅成低温热液金矿床的地质特征与成矿模式

对新疆东准噶尔哈尔里克构造带上双峰山金矿床的地质特征、矿床蚀变分带进行了初步研究，表明潜火山热液与火山热泉参与了成矿。这两个成矿阶段同源同位的蚀变矿物晕(带)叠套，造成双峰山矿床蚀变分带从上至下为隐爆硅质角砾岩化带、低金品位硅质岩带、石英(冰长石)网脉带(矿体)、黄铁矿蒙脱石化带和青磐岩化带。该矿床的成矿流体与晚古生代造山初期深成流纹质熔浆的陆相喷发有关。火山热泉循环形成蚀变晕，此阶段有大气降水的参与；潜火山热液成矿阶段发育的低温微细石英网脉中含冰长石和绢云母。双峰山矿床是晚古生代火山地区典型的冰长石-绢云母型浅成低温热液金矿床。