准噶尔盆地中拐地区下侏罗统层序地层特征与聚煤控制因素分析

在分析前人对准噶尔盆地层序地层学研究成果的基础上,综合应用岩心、测井和地震资料,对准噶尔盆地西北缘中拐地区下侏罗统进行层序地层划分,总结了层序和体系域界面的识别标志,将下侏罗统划分为4个三级层序和7个体系域,同时叙述了各三级层序的结构特征。通过对层序内含煤岩系的发育特点分析,发现其主力煤层主要发育在JSQI和JSQ3湖侵体系域中,本文作者认为研究区内湖侵时期为有利的聚煤时期,聚煤作用主要受构造沉降、物源供给、气候和沉积环境等因素的控制。     

羌塘盆地侏罗系碎屑岩储集层综合评价

运用储层综合评判分析方法对羌塘盆地侏罗系碎屑岩储集层进行分析和评价。首先选择影响储层性质的8种参数,包括定性参数,如岩性、成岩作用、储集空间类型和定量参数,如储层厚度、孔隙结构、物性等,对其进行单因素评价。在此基础上,根据各单因素对储层贡献的大小,确定各单因素的加权系数。最后,利用评判分析方法,计算各剖面的综合判别得分。综合判别分析评价表明,北羌塘坳陷中部、东部和中央隆起带北缘发育好储层;北羌塘坳陷西部发育中等储层;而南羌塘坳陷储层较差。     

青藏高原北部新生代陆相盆地石油地质条件及勘探前景

青藏高原北部陆相盆地中烃源岩发育层位包括始新统风火山组、渐新统雅西措组和中新统五道梁组。古近系雅西措组烃源岩,特别是灰岩属于中好烃源岩范畴,有机质类型较好,且烃源岩主体处于成熟阶段,是藏北高原新生代陆相盆地主力烃源岩的发育层位。陆相盆地储集岩较发育,储层较丰富,发育层位包括风火山组和雅西措组,其中雅西措组是储层主力分布层位。对测区分析数据表明：通天河盆地具备一定规模的生油岩厚度,而且有机质丰度为沱沱河地区最高,表明其勘探前景较好。     

Mesozoic-Cenozoic tectonics and geodynamics of Altai, Tien Shan, and Northern Kazakhstan, from apatite fission-track data

Apatite fission-track (AFT) thermochronological modeling as a diagnostic tool for periods of stability (peneplanation) and tectonic activity (orogeny) has been broadly used in tectonic studies of Central Asia in recent years. We discuss more than 100 AFT ages of samples from the Kyrgyz Tien Shan and Altai and compare them with AFT data from northern Kazakhstan. Geological, geomorphological, and AFT data indicate intense activity in the Late Cenozoic Eurasian continental interior. The impact from the India-Eurasia collision on the northern Tien Shan, Altai, and northern Kazakhstan regions showed up at 11, 5, and 3 Ma, respectively, as a result of stress propagation into the continent, with the ensuing reactivation and mountain growth. We hypothesize that a distant effect of the Late Cenozoic India-Eurasia collision was to rejuvenate Paleozoic fault zones and to deform the Mesozoic sedimentary cover north of the collision front as far as the West Siberian Plate. The reactivation facilitated formation of tectonic oil and gas traps. The activity in northern Central Asia under the effect of the Indian indentation into Eurasia appears to continue and may evolve to include uplift of southern West Siberian plate with uplift.     

节理岩体卸荷强度特性的试验研究

卸荷状态工程岩体的强度特性与传统的加载岩体有本质的区别。目前对于岩石卸荷强度特性的研究比较多见,但对于含节理的岩体在卸荷应力状态下的强度特性,尤其是节理面对其强度的影响研究实属少见。本文通过岩体三轴模拟试验研究了卸荷应力状态下节理岩体的破坏特征,突出考虑了节理面性质对卸荷强度的影响,在此基础上提出了节理岩体卸荷强度准则的一般表达式并进行了对比验证。     

肋柱式锚杆支挡结构的徐变次内力分析

采用老化徐变理论和等效弹性模量法,对肋柱式锚杆支挡结构的徐变影响提出了具体计算方法,并通过实例计算了支挡结构的徐变次内力。计算结果表明,在逆作法条件下,随着开挖深度的加大,岩土侧向压力也增大,使后期施工的混凝土构件产生的徐变次内力也随之增大;考虑徐变后使结构设计更加安全可靠,尤其坡脚处后期浇筑的混凝土构件,更要关注徐变的影响。     

西藏冈底斯带侏罗纪岩浆作用的时空分布 及构造环境

在新近完成的1：25万区域地质调查资料和相关研究成果的基础上,初步研究了西藏冈底斯带侏罗纪岩浆作用的分布特点及其年代学,并利用已有的地球化学数据重点分析了早期关注程度较低的侏罗纪花岗岩类岩浆作用的性质。目前在冈底斯弧背断隆带未发现侏罗纪火山岩;在冈底斯东部地区,早侏罗世岩浆活动几乎同时发生于南冈底斯（叶巴组火山岩和鸟郁、尼木花岗岩类）、冈底斯弧背断隆带（宁中、金达、布久花岗岩类）和北冈底斯（聂荣花岗岩类）,中晚侏罗世接奴群和拉贡塘组火山岩断续分布于北冈底斯,晚侏罗世岩浆活动零星分布于沙莫勒一麦拉一洛巴堆～米拉山断裂以北。将冈底斯侏罗纪岩浆活动置于时空框架内分析发现,南冈底斯和北冈底斯在侏罗纪时主要受俯冲作用的影响．而冈底斯弧背断隆带和中冈底斯自早侏罗世以来除了受到俯冲作用的影响外,还受到自东向西逐步扩展的碰撞作用的影响。结合古地磁重建资料和其他新发现．认为冈底斯带侏罗纪这种岩浆活动的特点可用班公湖一怒江洋壳向南、新特提斯洋壳向北的双向剪刀式（剪刀口向西张开）俯冲模式来解释。     

应用生烃动力学法研究川东上二叠统烃源岩生烃史

现今川东上二叠统烃源岩生烃史研究具有局限性.首先,没有对上二叠统Ⅰ-Ⅱ1型灰岩生油、Ⅲ型泥岩的生气史分开评价;其次,海相镜质组反射率通过拟合公式换算成镜质体反射率评价烃源岩成熟度具有局限性.针对上述不足,笔者通过热模拟实验,利用化学动力学方法,标定出两类源岩生油、生气的动力学参数,并结合川东地区的埋藏史及热史,模拟出源岩有机质的成烃转化率曲线.研究表明:上二叠统灰岩、泥岩有机质在距今200 Ma和190 Ma分别进入了生油、生气门限,而在距今170 Ma和140 Ma生烃结束.     

Rock magnetic record of Cenozoic lake sediments from the Linxia basin and aridification of the Asian inland

High resolution research of rock magnetic records and quartz sands from the Maogou Section in the Linxia basin reveals that after a relatively stable environment between 13.07 Ma and 8.6 Ma, the basin was gradually influxed by eolian dusts at about 8.6 Ma, with two rapid increases at about 6.4 Ma and 5.3 Ma, respectively. The study suggests that drying of northwest China began at 8.6 Ma and strengthened rapidly at about 6.4 Ma and 5.3 Ma. __________ Translated from Marine geology & Quaternary geology, 2007, 27(4): 103–110 [译自: 海洋地质与第四纪地质]     

The paleoclimatic records and the relevance with the formation of hydrocarbon source rocks:A case study of Huanghekou depression,Bohaiwan basin

Bohaiwan basin, covering an area of 200 000 km², is one of the most important oil-bearing basins in Eastern China. Rifting processes formed the basin, and two evolution phases can be recognized. The rifting phase developed in Paleogene, and post-rifting phase occurred in Neogene. More than 200 oil fields have been found in the onshore and offshore area in Bohaiwan basin in recent years. The distribution of the oil fields is closely related to the rich hydrocarbon depressions, and the Huanghekou depression is one of these rich hydrocarbon depressions. A number of large and medium-sized oil and gas fields have been found in this area, such as BZ25-1, BZ34 etc., and the hydrocarbon was mainly from the Huanghekou depression. The formation of rich hydrocarbon source rocks depended on the tectonic setting of rapid subsidence, favorable paleoclimatic conditions and paleolimnology environments. The effects of paleoclimatic condition on hydrocarbon source rocks are the focus of this paper. __________ Translated from Geological Bulletin of China, 2007, 26(7): 830–840 [译自: 地质通报]