滇西高原第四纪以来的隆升和剥蚀

由滇西高原内古夷平面的抬高、外流水系的河流阶地、高原外营歌海盆地和琼东南盆地的沉积响应,共同揭示滇西高原第四纪以来的快速隆升和剥蚀历史。第四纪以来滇西高原区域性抬升了610～700余米、被剥蚀了1095～1600m,其平均剥蚀速率为0．68～0．94mm／a。根据河流阶地计算出第四纪以来各时段的隆升速率;隆升在0．386～0．296Ma达到峰期,隆升速率为2．24～2．SOmm／a;1．6～0.647Ma隆升速率最缓慢为0．68～0．94mm／a。滇西高原第四纪以来的隆升量和隆升峰期与同期的青藏高原具有相似性,但隆升速率明显低于东喜马拉雅构造结的隆升速率。     

PALEOCENE—MIDDLE EOCENE DEXTRAL STRIKE-SLIP DEFORMATION AND ITS TECTONIC IMPLICATION IN THE WESTERN YUNNAN, CHINA

PALEOCENE—MIDDLE EOCENE DEXTRAL STRIKE-SLIP DEFORMATION AND ITS TECTONIC IMPLICATION IN THE WESTERN YUNNAN, CHINA     

四川盆地威远气田和资阳含气区震旦系油气成藏差异性研究

本文通过对四川盆地元古宇-下古生界勘探最成功的两个地区--威远震旦系气田和资阳震旦系含气区天然气成藏要素和成藏过程的详细比较,得出 ①资阳含气区和威远气田的原始烃源相同,均是下寒武统生成的油裂解的天然气,不同的是资阳为残留的气顶气,威远是水溶气脱溶气.②资阳含气区和威远气田震旦系碳酸盐岩基质孔隙度相近,资阳地区溶蚀洞穴发育,但裂缝不发育,储层渗透性较差,非均质性强;威远地区储层洞穴不发育,但裂缝发育,形成统一的裂缝-孔洞系统.③威远地区具有统一的圈闭,闭合度高(800 m),闭合面积大(895 km2).资阳含气区不具有统一的圈闭,多为局部的小高点.④喜马拉雅期隆升作用使资阳统一含气区分散化和气藏变小,形成多压力系统的含气区;威远地区快速大幅度隆升, 溶于水中的天然气脱溶, 形成具同一压力系统的整装气田.⑤资阳含气区的成藏过程为 (资阳-威远)古油藏→原油裂解→气顶天然气→隆升调整→现今(残留)含气区,其天然气藏是隆升调整成藏,是在原古气藏的基础上改造残留而成;威远地区的成藏过程则是(资阳-威远)古油藏→原油裂解→天然气大量溶于水中→隆升使得带有大量天然气的水向威远运移和天然气脱溶→现今(新生)气藏,属天然气的脱溶成藏.资阳含气区受古构造的控制明显;威远气田则主要受今构造的制约.因此, 在四川盆地震旦系和下古生界的油气勘探中, 既要研究其古构造的特征和演化, 也要研究今构造的特征和分布规律, 才能发现不同类型的天然气藏.     

光谱角技术在多光谱遥感蚀变异常提取工作中的应用

选择朱拉扎嘎金矿为试验区,ASTER数据为数据源,利用光谱角技术进行蚀变异常提取实验。重点阐述光谱角技术（SAM）在多光谱遥感蚀变异常提取工作中的两个关键技术：内部平均相对反射率法（IARR）大气校正和典型蚀变矿物波谱对应于ASTER波段重采样,最终通过光谱角计算提取了3种蚀变异常,分别为高岭土化蚀变异常、碳酸盐化蚀变组合异常和Fe-OH-蚀变组合异常。     

四川含油气叠合盆地基本特征

随着近年来四川盆地油气勘探的不断突破,重新审视其基本地质特征和油气成藏特点变得迫切而必要.四川盆地是典型的叠合盆地,显生宙以来经历了震旦纪一中三叠世伸展体制下的差异升降和被动大陆边缘(海相碳酸盐岩台地)、晚三叠世-始新世挤压体制下的摺皱冲断和复合前陆盆地(陆相碎屑岩盆地)、渐新世以来的褶皱隆升改造(构造盆地)3大演化阶...     

四川盆地东南缘震旦系-古生界古油藏特征

震旦系古油藏具有两期储层沥青,古生界仅见有一期储层沥青.震旦系储层沥青丰富,其丰度受到构造岩溶不整合面控制,古油藏为岩性-构造古油藏;古生界储层沥青含量较少,分布明显受到岩性控制,古生界古油藏为小型的岩性古油藏.丁山-林滩场构造带震旦系古油藏恢复规模为8.63×108t,裂解生气量为5348.698×108m3;良村志...     

Fluid Geochemical Features and Preservation Conditions of Marine Stratum in Typical Structure of Jianghan Plain Area

Many scholars carried out large quantity of researches on oil and gas preservative conditions of marine carbonate rocks from the aspects of cap rocks,faults,formation water,hydrodynamic,and tectonism.This article gives dynamic evaluation on oil and gas preservative conditions of marine stratum in Jianghan(江汉) plain of multiphase tectonic disturbance from the view of paleofluid geochemistry.The conclusion shows that there mainly existed fluid filling of two periods in the reservoir of Lower-Middle Triassic t...     

Hydrocarbon Accumulation Process in the Marine Strata in Jianghan Plain Area,Middle China

Marine strata in the Jianghan Plain area are widely distributed with a total depth of more than 8,000 m from the Upper Sinian to the Middle Triassic. Six reservoir caprock units, named Z–∈2, ∈2–O, S, D–C, P and T1, can be identified with each epoch. The geology, stratigraphy, drilling, oil testing and other basic data as well as the measured inclusion and strontium isotope data in the study area are used in the analysis of the formation and evolution process of marine petroliferous reservoirs in the Jianghan Plain area. This study aims to provide a scientific basis for the further exploration of hydrocarbons in the Jianghan Plain and reduce the risks by analyzing the key factors for hydrocarbon accumulation in the marine strata. Our findings show that in the Lower Palaeozoic hydrocarbon reservoir, oil/gas migration and accumulation chiefly occurred in the early period of the Early Yanshanian, and the hydrocarbon reservoir was destroyed in the middle–late period of the Early Yanshanian. In the Lower Triassic–Carboniferous hydrocarbon reservoir, oil/gas migration and accumulation chiefly occurred in the Early Yanshanian, and the hydrocarbon reservoir suffered destruction from the Late Yanshanian to the Early Himalayanian. The preservation conditions of the marine strata in the Jianghan Plain area have been improved since the Late Himalayanian. However, because all source beds have missed the oil/gas generation fastigium and lost the capacity to generate secondary hydrocarbon, no reaccumulation of hydrocarbons can be detected in the study area's marine strata. No industrially exploitable oil/gas reservoir has been discovered in the marine strata of Jianghan Plain area since exploration began in 1958. This study confirms that petroliferous reservoirs in the marine strata have been completely destroyed, and that poor preservation conditions are the primary factor leading to unsuccessful hydrocarbon exploration. It is safely concluded that hydrocarbon exploration in the marine strata of the study area is quite risky.     

北冈底斯带日松花岗岩体的锆石U-Pb测年和Hf同位素组成

在野外地质调查工作的基础上,对日土县-拉梅拉山口一带的日松花岗岩体开展了详细的岩相学、岩石地球化学、锆石U-Pb测年和Hf同位素分析。岩石地球化学数据表明,日松花岗岩体属钙碱性岩类型,绝大多数样品含透辉石标准分子。富集Rb、Pb、Th等而亏损K、Ba等大离子亲石元素,高场强元素Nb、Ta、Ti等明显亏损。稀土元素呈现出右倾缓倾斜型的特征,且存在较为明显的负Eu异常。与前人研究确定岩体的时代为晚白垩世-始新世不同,本文认为岩体的侵位时代主要为白垩纪,可分为早白垩世、晚白垩世两期。获得二长花岗岩样品（D1045-2）的LA-ICP MS锆石U-Pb年龄为108.4±2.1Ma（MSWD=2.4,n=18）,结合锆石稀土元素特征、岩浆振荡环带特征（CL图像）及锆石Th/U比值,上述年龄可以代表岩体的形成年龄（早白垩世）。锆石Hf同位素特征显示,二长花岗岩样品（D1045-2）的εHf（t）为正值,介于1.49-3.86间（平均值为2.50）;而石英闪长岩样品（D1045）的εHf（t）多数为负值,介于-2.09至0.15之间（平均值为-0.69）。Hf同位素地壳模式年龄分别在763.0-884.5Ma（D1045-2）、959.1-1073.5Ma（D1045）之间。两件样品的εHf（t）和Hf同位素地壳模式年龄均具有较小的变化范围,暗示岩体的岩浆物质来源应该具有较为均一的锆石Hf同位素组成。日松地区早白垩世花岗岩体的锆石U-Pb年龄和Hf同位素特征,基本反映了北冈底斯早白垩世的岩浆活动时间和源区等特征,其成因可能与班公湖-怒江特提斯洋岩石圈向南俯冲过程中幔源物质参与岩浆形成演化有关。本文研究成果,为研究班公湖-怒江结合带构造演化提供了新的资料证据。     

川西前陆盆地流体的跨层流动和天然气爆发式成藏

川西前陆盆地是我国西部典型的前陆盆地,也是我国重要的致密砂岩含气区。盆地上三叠统须家河组二段和四段等渗透层中的流体跨过须家河组三段、五段等不渗透层流入侏罗系自流井组、千佛岩组、沙溪庙组、遂宁组和蓬莱镇组等渗透层,即发生了流体的跨层流动。流体的跨层流动一方面使侏罗系砂岩发生了受酸性水控制的次生溶蚀作用,从而改善了侏罗系的储集条件;另一方面为侏罗系形成天然气藏提供了气源条件。盆地天然气成藏具有烟囱效应、早聚晚藏和异常高压等特征。深盆气是天然气早期聚集在川西前陆盆地上三叠统(主要是须二段和须四段)的基本形式,是后期天然气成藏的基础,本文称之为气库区。天然气藏形成是由地壳隆升作用致使早期聚集的气库区决口,引起流体跨层流动,天然气以速度快、规模大和范围窄的形式运移和聚集,本文称之为爆发式成藏。爆发式成藏形成了上三叠统晚期裂缝重组气藏和侏罗系气藏(并非都是次生气藏)两类气藏。早期天然气聚集和定位地区的确定和评价是今后川西前陆盆地天然气勘探的重点和难点。