由下扬子区海陆对比分析南黄海盆地下志留统烃源岩特征及其主控因素

针对南黄海盆地海相油气勘探的重大需求,在收集、整理下扬子苏、浙、皖地区地质和地化资料的基础上,依托科学钻探CSDP-2井岩心,系统对比了南黄海盆地与下扬子陆区早志留世古地理背景和沉积充填特征,进而利用一系列地化测试数据总结了南黄海盆地下志留统烃源岩特征并探讨其主控因素。研究结果表明：南黄海盆地大陆架科学钻探CSDP-2井目前已钻遇了坟头组和高家边组上部两套丰度很低的厚层、暗色（粉砂质）泥岩,其有机质类型主要为Ⅱ₂型,热演化程度已整体进入过成熟阶段;受控于全球海侵事件和扬子板块构造活动的发展阶段,早志留世初期深水陆棚环境逐渐向后期的浅水陆棚环境演变,加之早期较高的初级生产力和良好的保存条件,使得下扬子区高家边组下部烃源岩的品质明显高于上部,并以底部黑色笔石页岩段有机质丰度最高。因此,南黄海盆地高家边组底部理应存在一套优质烃源岩层,可作为下一步页岩气勘探的重点层位。     

松动岩体工程特性研究——以雅砻江楞古水电站松动岩体为例

为了对松动岩体的工程特性进行系统研究,以楞古水电站厂址区边坡为例,对该边坡岩体进行了详细的地质编录和物理勘探试验,重点对节理裂隙的空间发育规律、镶嵌结构和碎裂结构岩体的发育深度及空间分布、软弱结构面发育分布规律以及边坡已有变形破坏特征这四个方面进行了系统的统计和分析,认为松动岩体是区域断裂活动和浅表生改造的结果,岩体工程效应差、变形模量低;同时结合应力测试、声波测速、高密度电磁勘探等试验成果进行分析,结果显示松动岩体具低波速（波速大部分小于3 000 m/s）、低应力（最大主应力不超过20 MPa）、强透水性（透水性系数大于10 L/（min·m·m））。认为岩体破碎主要受断层及节理裂隙影响,分析了岩体破裂松动的演化过程及特征。     

缝网间距对高温岩体储留层温度影响规律模拟

为研究高温岩体储留层注水过程中缝网间距对储留层岩体温度的影响规律,建立了考虑热对流和热传导效应的热流固耦合力学模型。以水平井多簇缝网地热开发为例,将缝网及其周围岩体简化为等效的多孔介质,利用ABAQUS二次开发功能实现了流固耦合和热对流耦合。模拟结果表明：储留层岩体温度的变化按注水持续时间分为3个阶段：初温保持阶段,该阶段储留层岩体温度保持原始温度,缝网间距的不同对储留层岩体整体温度无影响;快速降温阶段,该阶段储留层岩体温度下降随注水时间呈现负指数变化规律,缝网间距与储留层岩体温度呈正相关关系;温度缓慢下降平稳阶段,该阶段初期缝网间距与储留层岩体温度的关系和快速降温阶段一致,但后期缝网间距与储留层岩体温度呈负相关关系。空间上,在岩体温度高的区域,缝网间距越小,岩体温度变化梯度越大;在岩体温度较低的区域,缝网间距越小,岩体温度变化梯度越小。     

基于地震波速度预测岩体物性参数模型与应用

以地震属性和钻孔测井参数为基础,依据试验数据构建数学模型,实现对煤层顶底板岩石物性参数的定量预测。通过试验拟合出纵横波波速之间关系、波速与密度的关系、动静杨氏模量、动静泊松比之间的关系,且相关程度较高。依据试验模拟结果对淮南刘庄区煤层顶底板岩石物性参数及孔隙度进行了预测。结果表明该地区的物性参数分布规律明显,且与实测结果吻合较好。模型计算与实例应用证实地震信息用于预测岩石力学参数具有可行性。     

扬子西缘小相岭地区苏雄组古火山机构的发现及意义

通过详细的野外地质调查,发现扬子西缘小相岭地区苏雄组火山岩由巨厚的酸性-中酸性熔岩、火山碎屑岩和少量基性熔岩组成,在小相岭山脊两侧首次厘定4处古火山机构。其中,阳糯雪山古火山机构最壮观,是由火山颈相、溢流相、爆发相和火山沉积相构成的完整古火山机构。通过系统的地质剖面研究,发现该古火山机构存在2次喷发亚旋回和15个火山韵律,2次喷发亚旋回之间出现了1次明显的火山间歇期。小相岭地区古火山机构的发现,进一步厘定了苏雄组火山岩的喷发方式和构建特征,对进一步研究苏雄组酸性火山碎屑岩的起源及新元古代陆内裂谷作用具有重要意义。     

An integrated ore prospecting model for the Nyasirori gold deposit in Tanzania

The Nyasirori gold deposit, located in the middle-western end of the Musoma-Mara Archean greenstone belt in Tanzania, is a tectonic altered rock type gold deposit controlled by shear tectonic zone. This work conducted high-precision ground magnetic measurements to delineate fault structures and favorable prospecting targets, utilized induced polarization (IP) intermediate gradient to roughly determine the distribution and extension of the tectonic altered zone and gold ore (mineralized) bodies, and further carried out IP sounding and magnetotelluric sounding to locate the tectonic altered zone and gold ore (mineralized) bodies. The anomalous gradient belt of the combination of positive and negative micromagnetic measurements reflects the detail of shallow surface tectonic alteration zone and gold mineralization body. Micromagnetic profile anomalies indicate the spatial location and occurrence of concealed tectonic alteration zone and gold (mineralized) ore bodies. Soil geochemical measurements indicate that the ore-forming element Au correlates well with As and Sb, and As and Sb anomalies have a good indication to gold orebodies. Based on the multi-source geological-geophysical-geochemical information of the Nyasirori gold deposit, this work established an integrated prospecting model and proposed a set of geophysical and geochemical methods for optimizing prospecting targets.     

ECONOMIC GEOLOGY

正20142114Lin Quansheng(China University of Geosciences,Bejing 100083,China)On the Geologic Characteristics and Economic Significance of the Cambrian Lintian Group in Fujian Province(Geology of Fujian,ISSN1001-3970,CN35-1080/P,32(4),2013,p.264-273,2illus.,2tables,6refs.)     

SEDIMENTARY PETROLOGY

正20141430 Chen Ji(Key Laboratory of Petroleum Resources,Chinese Academy of Sciences,Lanzhou 730000,China);Shi Ji’an Sedimentary Facies and Models for the Palaeogene-Neogene Deposits on the Northern Margin of the Qaidam Basin,Qinghai Province(Sedimentary Geology and Tethyan Geology,ISSN1009-3850,CN51-1593/P,33(3),2013,p.16-26,14 illus.,16 refs.)     

GEOTHERMICS GEOLOGY

正20141588 Guo Shiyan(Green Energy Geothermai Development Co.,SINOPEC,Xianyang 712000,China);Li Xiaojun Reservoir Stratum Characteristics and Geothermal Resources Potential of Rongcheng Uplift Geothermal Field in Baoding,Hebei Province(Chinese Journal of Geology,ISSN0563-5020,CN11-1937/P,48(3),2013,p.922-931,2 illus.,4 tables,10 refs.)Key words:geothermal fields,Hebei Province     

A depth average SPH model including μ(I) rheology and crushing for rock avalanches

Classical depth-integrated smoothed particle hydrodynamics (SPH) models for avalanches are extended in the present work to include a μ(I)− rheological model enriched with a fragmentation law. With this improvement, the basal friction becomes grain distribution dependent. Rock avalanches, where grain distribution tends to change with time while propagating, are the appropriate type of landslide to apply the new numerical proposal. The μ(I)− rheological models considered in the present work are those of Hatano and Gray, combined with two different fragmentation laws, a hyperbolic and a fractal-based law. As an application, Frank avalanche, which took place in Canada in 1903, is analyzed under the scope of the present approach, focusing in the influence of the rheological and fragmentation laws in the evolution of the avalanche.