海拉尔盆地贝尔凹陷含片钠铝石沉凝灰岩的成岩作用

以海拉尔盆地贝尔凹陷大磨拐河组-伊敏组的含片钠铝石火山碎屑岩为研究对象,采用偏光显微镜、扫描电镜及配套能谱、茜素红 S染色、阴极发光和X 射线衍射分析等技术手段,对研究样品的岩石类型、自生矿物种类及共生序列进行了详细研究。贝尔凹陷发育片钠铝石的宿主岩石类型为沉凝灰岩,自生矿物以发育片钠铝石、铁白云石和菱铁矿三种碳酸盐矿物为主,片钠铝石含量高达25%。成岩共生序列为菱铁矿Ⅰ→高岭石、石英次生加大→片钠铝石→微晶石英→方解石→铁白云石→菱铁矿Ⅱ→沥青。不同于国内外其它地区发现片钠铝石的主要产状为充填孔隙,本区内发育的片钠铝石以交代长石、石英、岩屑颗粒和高岭石基质为赋存特征,表明沉凝灰岩中的长石、岩屑、高岭石基质可以为其提供金属离子物质来源,并在CO2参与下,与成岩流体反应生成片钠铝石。大量碳酸盐矿物（15-44%）的发育证明了火山碎屑岩具有较高的CO2矿物捕获能力。     

海拉尔盆地贝尔凹陷火山碎屑岩自生碳酸盐矿物分布及对储层物性的影响

为了查明火山碎屑岩中自生碳酸盐矿物的分布特征及对储层物性的影响,以海拉尔盆地贝尔凹陷火山碎屑岩为研究对象,调查火山碎屑岩中自生碳酸盐矿物的类型,并通过统计50余口探井的碳酸盐含量及储层物性数据,探讨其分布特征及对储层物性的影响。结果表明：海拉尔盆地贝尔凹陷火山碎屑岩中自生碳酸盐矿物主要为方解石和白云石,其次为菱铁矿、片钠铝石和铁白云石;纵向上随着埋藏深度增加出现两个碳酸盐含量高值带,分别出现在1 500～1 900m和2 200～2 700m深度,前者主要为以胶结作用为主的连生方解石和显晶方解石及菱铁矿,后者主要为以交代作用为主的晚期方解石、白云石、铁白云石和片钠铝石;湖底扇等分选较差的沉积相为碳酸盐矿物发育的有利相带,扇-辫状河三角洲相为次有利相带;靠近德尔布干深大断裂的井碳酸盐含量要高于远离该断裂的井,且在该断裂附近的德2、德6和德8等井中见片钠铝石自生矿物,这主要因为断层是CO2逸散的通道,断层处的富CO2流体能够与围岩反应生成碳酸盐矿物;熔结凝灰岩和凝灰岩中的碳酸盐矿物含量要高于沉凝灰岩、凝灰质砂岩及普通砂岩,这主要因为火山岩及火山碎屑物质中金属离子含量高,易于释放,从而结合CO23-形成碳酸盐矿物;贝尔凹陷内储层孔隙度和渗透率等参数与碳酸盐含量呈负相关关系,说明碳酸盐含量对储层物性主要起破坏作用。     

海拉尔盆地乌尔逊凹陷与松辽盆地孤店C02气田含片钠铝石砂岩的岩石学特征

海拉尔盆地乌尔逊凹陷南屯组与松辽盆地孤店CO2气田泉头组发育大量含片钠铝石砂岩.通过偏光显微镜、扫描电镜、茜素红-S染色、X射线衍射、电子探针与INCA能谱分析等,对含片钠铝石砂岩的骨架碎屑组分、胶结物与自生矿物、成岩共生序列等岩石学特征进行了系统研究.研究表明,含片钠铝石砂岩的岩石类型为长石砂岩和岩屑长石砂岩,粒度以细粒、细-中粒为主,分选差-中等.砂岩中胶结物主要为次生加大石英、自生石英、片钠铝石、铁白云石和牯土矿物.其中,片钠铝石最高可达砂岩总体积的22%,在砂岩中或以放射状、束状、菊花状、杂乱毛发状、毛球状、板状等集合体充填孔隙,或呈束状和板状交代长石和岩屑.电子探针与INCA能谱综合分析表明,片钠铝石主要由Na、AI、O、C等组成.在含片钠铝石砂岩中,成岩共生序列依次为牯土矿物包壳-次生加大石英、自生石英、自生高岭石-油气充注-CO2充注-片钠铝石-铁白云石.其中,CO2注入前形成的自生矿物组合主要为次生加大石英、自生石英和自生高岭石,C02注入后形成的自生矿物组合主要为片钠铝石和铁白云石.     

贝尔凹陷沉凝灰岩储层片钠铝石前体矿物研究

为拓展CO2封存的储层选取范围,研究CO2充注过的储层中矿物的赋存状态,通过薄片鉴定、扫描电镜分析、X--射线衍射分析及铸体图像分析等技术对贝尔凹陷含片钠铝石储层进行了系统研究。研究区发育片钠铝石的岩石类型为沉凝灰岩,储层深度范围为882.26~941.4 m,该类储层发育有2类9种储集空间类型,以次生孔隙为主,属于低孔低渗储层。岩石骨架碎屑颗粒石英、长石、岩屑均有不同程度溶蚀;自生矿物以片钠铝石、铁白云石和菱铁矿为主。片钠铝石主要以充填溶蚀孔隙或交代颗粒的形式产出。综合研究区岩相学、矿物含量和热力学分析结果,长石和片钠铝石的生成具有亲缘性,为片钠铝石的形成提供了必要的元素和生长空间。     

海拉尔盆地乌尔逊凹陷与松辽盆地孤店CO2气田含片钠铝石砂岩的岩石学特征

海拉尔盆地乌尔逊凹陷南屯组与松辽盆地孤店CO₂气田泉头组发育大量含片钠铝石砂岩。通过偏光显微镜、扫描电镜、茜素红-S染色、X射线衍射、电子探针与INCA能谱分析等,对含片钠铝石砂岩的骨架碎屑组分、胶结物与自生矿物、成岩共生序列等岩石学特征进行了系统研究。研究表明,含片钠铝石砂岩的岩石类型为长石砂岩和岩屑长石砂岩,粒度以细粒、细-中粒为主,分选差-中等。砂岩中胶结物主要为次生加大石英、自生石英、片钠铝石、铁白云石和粘土矿物。其中,片钠铝石最高可达砂岩总体积的22％在砂岩中或以放射状、束状、菊花状、杂乱毛发状、毛球状、板状等集合体充填孔隙,或呈束状和板状交代长石和岩屑。电子探针与INCA能谱综合分析表明,片钠铝石主要由Na、Al、O、C等组成。在含片钠铝石砂岩中,成岩共生序列依次为粘土矿物包壳-次生加大石英、自生石英、自生高岭石-油气充注-CO₂充注-片钠铝石-铁白云石。其中,CO₂注入前形成的自生矿物组合主要为次生加大石英、自生石英和自生高岭石,CO₂注入后形成的自生矿物组合主要为片钠铝石和铁白云石。     

松辽盆地红岗油田白垩系青山口组含片钠铝石砂岩自生矿物共生序列

松辽盆地红岗油田白垩系青山口组发育含片钠铝石砂岩。通过偏光显微镜、扫描电镜、阴极发光 仪、Ｘ射线衍射等多种技术手段,对含片钠铝石砂岩的碎屑成分、胶结物类型及自生矿物共生序列等特征进行 了研究。该区含片钠铝石砂岩为岩屑长石砂岩及长石岩屑砂岩,胶结物有次生加大长石、次生加大石英、自生 石英微晶、黏土矿物、片钠铝石、方解石、铁方解石及铁白云石。方解石的形成分为两期,第１期方解石为原 始生物碎屑颗粒溶蚀溶解的产物,第２期方解石可能与ＣＯ^２ 充注后钙长石及早期碳酸盐矿物的溶蚀溶解有关。 含片钠铝石砂岩的自生矿物共生序列为：次生加大长石、早期次生加大石英-自生石英微晶-早期高岭石、第１ 期方解石、片钠铝石-晚期次生加大石英-晚期高岭石、第２期方解石、铁方解石、铁白云石。其中ＣＯ^２ 注入 后的矿物共生组合为：片钠铝石-晚期次生加大石英-晚期高岭石、第２期方解石、铁方解石、铁白云石。     

蒙古国塔木察格盆地塔南凹陷铜钵庙组火山碎屑岩中片钠铝石胶结物的成因

塔木察格盆地塔南凹陷铜钵庙组火山碎屑岩中发育大量的片钠铝石自生矿物。通过偏光显微镜、扫描电镜及X射线衍射分析等,查明了火山碎屑岩中的胶结物与自生矿物类型和成岩共生序列。含片钠铝石火山碎屑岩的成岩共生序列为粘土包壳-方解石-一期微晶石英-一期高岭石-二期微晶石英、二期高岭石、片钠铝石-铁白云石;通过MAT253稳定同位素质谱仪确定了片钠铝石和铁白云石的稳定同位素组成为片钠铝石的δ¹³C_PDB为-8.15‰~-2.81‰,与片钠铝石平衡的CO₂的δ¹³C_CO2为-12.91‰~-7.55‰,通过与海拉尔盆地及BGS盆地系碳氧同位素数据的类比,表明片钠铝石中的碳主要为幔源岩浆来源,形成片钠铝石的钠和铝主要来源于安山岩岩屑、长石晶屑碎屑、玻屑和火山灰等;铁白云石的δ¹³C_PDB为-6.76‰~-2.65‰,与片钠铝石的碳氧同位素数据相似,结合相关地质实例及地球化学模拟实验,可以推断铁白云石中的碳也是幔源岩浆来源,铁白云石中的铁离子主要来源于安山岩岩屑、玻屑、火山灰和蒙脱石等矿物。     

松辽盆地南部乾安油田青山口组含片钠铝石砂岩的成岩作用

松辽盆地南部乾安油田青山口组发育大量含片钠铝石砂岩.通过偏光显微镜、扫描电镜、茜素红-S染色和X-射线衍射分析等,对含片钠铝石砂岩的骨架碎屑成分、胶结物与自生矿物、成岩共生序列和流体演化等进行了系统研究.结果表明:松辽盆地南部乾安油田含片钠铝石砂岩的粒度为粉砂、微粒-细粒,分选中-好,岩石类型为微粒含片钠铝石长石砂岩、微粒含片钠铝石岩屑长石砂岩.胶结物与自生矿物主要为片钠铝石、铁白云石、方解石、次生加大石英、自生粘土矿物(高岭石及伊利石).片钠铝石一部分以放射状、束状和板状等产出,另一部分呈凝块状大面积地连片出现,尤为特殊.成岩共生序列依次为方解石-自生高岭石、次生加大石英-伊利石-片钠铝石、铁白云石.CO2注入前形成的自生矿物组合主要为多期方解石组合,高岭石、次生加大石英组合;CO2注入之后形成了片钠铝石和铁白云石组合.流体演化过程为碱性流体环境-酸性流体环境-酸性流体向碱性流体过渡或偏碱性流体环境-碱性流体环境.     

海拉尔盆地贝尔凹陷南屯组火山碎屑岩成岩作用的讨论

利用偏光显微镜、扫描电镜、染色法以及X-衍射分析等方法,查明南屯组火山碎屑岩成岩作用模式.研究表明火山碎屑岩成岩作用方式包括：机械压实作用、胶结作用与自生作用、交代作用和溶蚀溶解作用.成岩共生序列为：黏土矿物包壳-泥晶碳酸盐矿物、自生蒙皂石、自生伊利石-长石溶解-自生石英-自生高岭石-绿泥石、白云石-铁方解石-铁白云石.成岩阶段划分为早成岩阶段B期和中成岩阶段A期,并且以中成岩阶段A期为主.     

东北及邻区中生代盆地片钠铝石的分布、产状及其油气地质意义

东北及邻区中生代地层中的片钠铝石分布于海拉尔盆地、塔木察格盆地、二连盆地、开鲁盆地和阜新盆地的早白垩世地层及松辽盆地南部的早白垩世晚期-晚白垩世早期地层中.片钠铝石主要发育在油气储层或CO2气储层中富含长石的砂岩和火山碎屑岩中.在含片钠铝石砂岩和火山碎屑岩中,片钠铝石以放射状、束状、杂乱毛发状、球状和板状等集合体充填孔隙,或呈束状和板状交代长石和岩屑.片钠铝石及其共生的铁白云石都是最晚形成的自生矿物组合.越来越多的证据表明,片钠铝石是富CO2流体的指示矿物,记录了CO2和油气双重充注现象.在含片钠铝石碎屑岩中可以解读出CO2充注的时间和CO2分压的变化.     

The terrestrial fauna of the Late Triassic Pant-y-ffynnon Quarry fissures,South Wales,UK and a new species of Clevosaurus (Lepidosauria: Rhynchocephalia)

Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco.     

Définition d'une limite multicritère ; stratigraphie du passage Campanien–Maastrichtien du site géologique de Tercis (Landes,SW France)Definition of a multi-criteria boundary; stratigraphy of the Campanian–Maastrichtian interval of the geological site at Tercis (Landes,SW France)

Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414.     

The effect of water on accessory phase solubility in subaluminous and peralkaline granitic melts

The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H₂O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H₂O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species.     

Quaternary stresses revealed by calcite twinning inversion: insights from observations in the Savonnières underground quarry (eastern France)

Calcite samples were extracted both from the rock matrix and the superficial coating of a karstified fault plane of an underground quarry, located in the eastern border of the Paris basin. The karstification is dated as Quaternary. Analysis of mechanical calcite twinning reveals that only the calcite matrix has also undergone a compression trending WNW that can be attributed to the Mio-Pliocene alpine collision. Both coating and matrix have undergone a strike-slip regime with σ₁ roughly trending north–south, that could correspond to the regional present-day state of stress, a strike-slip compression rather trending NNW, modified by local phenomena. To cite this article: M. Rocher et al., C. R. Geoscience 335 (2003).     

HYDROGEOLOGY

正20141756 Chen Ruige(Mathematical College,China University of Geosciences,Beijing100083,China);Zhou Xun Numerical Simulation of Groundwater Level Fluctuation in a Coastal Confined Aquifer with Sloping Initial Groundwater Level Induced by the Tide(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(7),2013,p.1099-1104,6 illus.,16 refs.) Key words:confined water,groundwater level     

METAMORPHIC PETROLOGY

正20141408 Cai Jia(Institute of Geology,Chinese Academy of Geological Sciences,Beijing100037,China);Liu Fulai Petrogenesis and Metamorphic P-T Conditions of Garnet-Spinel-Biotitebearing Paragneiss in Danangou Area,Daqingshan-Wulashan Metamorphic Complex Belt(Acta Petrologica Sinica,ISSN1000-0569,CN11-1922/P,29(7),     

SERIALS

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GEOPHYSICAL EXPLORATION

正20142386An Guoying(China Aero Geophysical Survey and Remote Sensing Center for Land and Resources,Beijing 100083,China)Application of Satellite Remote Sensing in Regional Hydrogeological Investigation:Taking Cenozoic Strata in Wenquan Sheet(1∶250 000)of Karakoram Range as an Example(Geosci-     

QUATERNARY GEOLOGY & GEOMORPHOLOGY

正20141016An Chengbang(Key Laboratory of Western China’s Environmental Systems,Ministry of Education,Lanzhou University,Lanzhou 730000,China);Zhao Yongtao Lake Records during the Last Glacial Maximum from Xinjiang,NW China and Their Climatic Impli-     

PETROLEUM GEOLOGY

正20141538 Cao Qing(School of Earth Sciences and Engineering,Xi’an Petroleum University,Xi’an 710065,China);Zhao Jingzhou Characteristics and Significance of Fluid Inclusions from Majiagou Formation,Yichuan Huangling Area,Ordos Basin(Advances in Earth Science,ISSN1001-8166,CN62-1091/P,28(7),2013,p.819-828,7 illus.,3 tables,43 refs.)