Fault Systems and their Control of Deep Gas Accumulations in Xujiaweizi Area

A study of faults and their control of deep gas accumulations has been made on the basis of dividing fault systems in the Xujiaweizi area. The study indicates two sets of fault systems are developed vertically in the Xujiaweizi area, including a lower fault system and an upper fault system. Formed in the period of the Huoshiling Formation to Yingcheng Formation, the lower fault system consists of five fault systems including Xuxi strike-slip extensional fault system, NE-trending extensional fault system, near-EW-trending regulating fault system, Xuzhong strike-slip fault system and Xudong strike-slip fault system. Formed in the period of Qingshankou Formation to Yaojia Formation, the upper fault system was affected mainly by the boundary conditions of the lower fault system, and thus plenty of multi-directionally distributed dense fault zones were formed in the T2 reflection horizon. The Xuxi fault controlled the formation and distribution of Shahezi coal-measure source rocks, and Xuzhong and Xudong faults controlled the formation and distribution of volcanic reservoirs of Y1 Member and Y3 Member, respectively. In the forming period of the upper fault system, the Xuzhong fault was of successive strong activities and directly connected gas source rock reservoirs and volcanic reservoirs, so it is a strongly-charged direct gas source fault. The volcanic reservoir development zones of good physical properties that may be found near the Xuzhong fault are the favorable target zones for the next exploration of deep gas accumulations in Xujiaweizi area.     

邯邢地区燕山期多重火成岩系的成因

邯邢地区燕山期火成杂岩由一系列基性—超基性、中基性、中偏碱性和碱性的侵入体组成。火成活动发生在109～171Ma之间。可将该区火成杂岩划分成4个系列,它们为角闪橄辉岩系,角闪闪长岩系,二长岩系和正长岩系。岩石化学特征表明不同岩系具有独立的成因,矿物分离结晶作用是控制岩浆演化的主导机制。文中提出的多重火成岩系是指同一造山旅回的不同阶段,在同一地区产出的来自不同源区的多个火成岩系的共存。     

月球雨海盆地多环结构的厘定及其深部构造研究

雨海盆地是月球正面最大、月球上研究程度最高的多环结构撞击盆地,已有很多学者对其多环结构的边界进行恢复研究,但在多环结构最初始形状、多环位置/数量、盆地大小等方面,至今未能达成共识。本文利用GRAIL自由空气重力异常数据、LOLA激光测高数据进行了多源数据的融合,结果表明,雨海盆地是具有偏心圆的三环结构特点,其直径从外到内分别为1 500 km、1 100 km、665 km。基于欧拉反演结果研究表明,在雨海撞击盆地中部存在两种不同深度、构造运动性质及方向的断裂构造,即：(1)深度大于40 km,向下逐渐向内倾斜、延伸的深部断裂构造;(2)深度在40 km以内,由月表向下逐渐向外倾斜、延伸的浅部断裂构造。结合物质成分及地球物理特征的研究,雨海地区的地质构造演化过程可分为两个阶段：(1)在月球早期阶段(45~38.5亿年),主要以内动力地质作用即岩浆洋冷凝过程为主,形成了雨海盆地深度在40 km以下逐渐向内倾斜、延伸的构造断裂,其为本区在月球早期深部岩浆洋产生、分异及运移提供了通道,该构造断裂代表了雨海盆地撞击前的月球早期深部岩浆洋的构造地质演化阶段;(2)在月球晚期阶段(≤38.5亿年),主要以内、外动力地质作用并重,形成了雨海盆地深度在40 km以内逐渐向外倾斜、延伸的构造断裂,其应为本区不同期次的玄武质岩浆喷出或溢流到月表提供了运移通道,该构造断裂代表了雨海盆地撞击后的月球晚期不同期次玄武质岩浆喷发、充填溢流的月海岩浆活动作用的构造地质演化阶段。     

青藏高原地面有效辐射变化及其对表层土温的影响

利用青藏高原格尔木、狮泉河、昌都日射站及中国科学院冰冻圈观测研究站的观测资料,分析了高原有效辐射的变化,在此基础上结合土壤温度资料讨论了高原北部有效辐射的变化对表层土壤热状况的影响.结果显示：1）青藏高原有效辐射变化因所处的区域不同而异,高原东北部、西部及高原腹地有效辐射总体呈减小的趋势,高原东南部有效辐射呈增大的趋势...     

粉煤灰制备硫铝酸钙-阿利特水泥熟料的研究

以粉煤灰为主要原料, CaF2为矿化剂,设计MG和MS值,控制CaO和CaSO4含量,分别在1 150、1 200、1 250、1 300和1 350℃温度下烧制高胶凝性硫铝酸钙-阿利特复合矿相水泥熟料.运用X射线粉晶衍射(XRD)和扫描电镜(SEM)等手段,研究原料配方和煅烧温度对熟料物相组成的影响,对熟料物相形成的反应历程作了探讨.实验结果表明,在1-300℃,当MG=1.05、MS =0.95时,形成较理想的熟料,物相组成约为C4A3-S 58.73%,C3S 23.99%,C2S 2.87%,C11A7·CaF2/C12A7 14.07 %,f-CaO 0.35%.熟料中主要物相硫铝酸钙晶体呈菱形十二面体,发育完整,形态规则,颗粒大小约为1～3 μm;阿利特(C3S)相物相为板状六角形,晶体发育相对细小.     

应用Adobe Photoshop定量分析岩石结构

岩石薄片定量研究中常用的有肉眼估计、比较图表估计、数点法和图像分析四种定量或半定量分析方法,但Adobe Photoshop比一般的图像分析软件更能迅速、详细和准确地对岩石结构进行定量。其原理是利用Photoshop软件强大的选取功能,对各结构组分进行精细选取,查看选区像素值和总像素值的比值即可得到各自所占百分含量。因此,能定量分析碳酸盐岩中的颗粒、胶结物和孔隙含量,及各种矿物含量和各类孔隙的面积百分含量,继而可定量化分析碳酸盐岩的成岩和孔隙演化历史。其它岩石类型与此类似。川东北PG2井的实例分析表明,Photoshop定量分析法具有很强的实用性和准确性,可广泛应用于各类岩石结构的定量化研究。     

Late Mesozoic compressional to extensional tectonics in the Yiwulüshan massif,NE China and their bearing on the Yinshan–Yanshan orogenic belt: Part II: Anisotropy of magnetic susceptibility and gravity modeling

Granitoids play an important role in deciphering both crustal growth and tectonic evolution of Earth. In the eastern end of the Yinshan–Yanshan belt of North China Craton, the Yiwulüshan massif is a typical region that presents the tectonic evolution features of this belt. Our field work on the host rocks has demonstrated two phases of opposite tectonics: compressional and extensional, however, the deformation is almost invisible in the intrusive rocks. To improve the understanding of the tectonic evolution of the Yiwulüshan massif and the Late Mesozoic tectonics of East Asia, a multidisciplinary study has been carried out. In this study, anisotropy of magnetic susceptibility (AMS) and gravity modeling have been applied on these Jurassic plutons (Lüshan, Jishilazi and Guanyindong), which intrude into the Yiwulüshan massif. According to laboratory measurements and microscopic observations on thin sections, the AMS of the Yiwulüshan massif is characterized by secondary fabrics, indicating that the intensive post solidus deformation has reset the (primary) magmatic magnetic fabrics. A relatively gentle NW dipping magnetic foliation has been identified with two distinct groups of magnetic lineations of N34°E and N335°E orientations, namely L_M1 and L_M2, relatively. Gravity modeling reveals a southward thinning of the massif with a possible feeding zone rooted in the northern part of the massif. Integrating all results from structural observation, geochronological investigation, AMS measurement and gravity modeling, two tectonic phases have been identified in the Yiwulüshan massif, posterior to the Jurassic (180–160 Ma) magmatism in the Yinshan–Yanshan area. The early one concerns a Late Jurassic–Early Cretaceous (~ 141 Ma) compressional event with a top-to-the-south to southwest sense of shear. The second one shows an Early Cretaceous (~ 126 Ma) NW–SE ductile extensional shearing. At that time, sedimentary basins widened and Jurassic plutons started to be deformed under post solidus conditions. In fact, the NW–SE trend of the maximum stretching direction is a general feature of East Asian continent during Late Mesozoic.     

扬子克拉通东南缘新元古代陆缘弧型TTG的厘定及其构造意义

在扬子克拉通东南缘的江山-绍兴结合带沿线多处出露新元古代深成杂岩,以往被认为是沿扬子克拉通和华夏地块碰撞缝合带侵入的板内型深成岩类。本文选择其中的浙江金华罗店中酸性深成杂岩进行了系统的岩石学、年代学和地球化学研究,提出它们属TTG岩石组合,包括英云闪长岩-奥长花岗岩-花岗闪长岩组合(T1T2G1)和二长花岗岩-花岗岩组合(G2QM)两类,普遍以明显富集Rb、Ba、K、Pb等大离子亲石元素而强烈亏损Nb、Ta、Ti、P等高场强元素为特征,δCe为弱负异常或无异常,属典型的弧岩浆岩类。T1T2G1组合富钠贫钾,εNd(t)值=+2.6~+9.4,Mg#值为41.5~63.1,推断由玄武质俯冲板片脱水部分熔融而成,并受到地幔楔橄榄岩熔体的混染。G2QM组合与T1T2G1组合地球化学特征类似,但又明显富K2O(2.75%~5.08%)、LILE和LREE,低Mg#值(27.2~52.31)和εNd(t)值(+1.7~+2.0),应是T1T2G1源区继续部分熔融的产物,可能未受到明显的地幔楔橄榄岩混染。测得花岗闪长岩(G1)锆石SHRIMP U-Pb年龄为841±10Ma,奥长花岗岩(T2)锆石LA-ICPMS U-Pb年龄为793±13Ma,前人报道之花岗岩(G2)年龄为832±44Ma,结合上述地球化学特征,说明T1T2G1和G2QM组合是由新元古代古华南洋向扬子东南缘持续俯冲形成的。综合区域地质资料及前人研究结果,提出金华罗店与诸暨璜山、绍兴平水等地的深成杂岩共同构成了扬子克拉通东南缘一条长达200km的青白口纪(930~793Ma)陆缘弧型深成杂岩带,反映迟至793Ma前仍存在强烈的洋壳俯冲,扬子克拉通尚未与华夏地块发生碰撞拼合,且T1T2G1-G2QM组合的出现指示洋壳俯冲正处于早-中期阶段。     

海拉尔盆地贝尔凹陷伸展断层转折褶皱作用及其对沉积作用的制约

海拉尔盆地是叠置于内蒙－大兴安岭古生代碰撞造山带之上的中新生代盆地,总体上呈北东向展布,由3坳、2隆5个一级构造单元组成,自西向东依次为扎贲诺尔坳陷、嵯岗隆起、贝尔湖坳陷、巴彦山隆起和呼和湖坳陷, 其中贝尔凹陷是贝尔湖坳陷南部的1个二级构造单元。贝尔凹陷的控陷断层为1个上凸、2个上凹断层转折组合构成的犁式正断层,在深部发育伸展双重构造。在犁式正断层上盘由于上凸断层转折产生的活动轴面与断层面为同旋向剪切,而上凹断层转折产生的活动轴面与断层面为反旋向剪切,在断层上盘形成2个背斜中间夹1个向斜的构造组合。由活动轴面与固定轴面之间滚动面的宽度确定控陷断层F₁在早白垩世南屯期晚期的水平伸展量为6 850 m。贝尔坳陷伸展断层转折褶皱的几何学和运动学特征,反映了断层滑移速率、构造沉降速率和沉积速率对凹陷内沉积地层变形特征的影响和构造活动对沉积作用和油气地质条件的制约。贝尔凹陷南屯组上段内部角度不整合的形成与变形作用中的剥蚀作用和沉积间断无关,而是由于半地堑从略欠补偿充填向过补偿充填状态转变时,沉积速率相对于构造沉降速率显著增加所致。