查干凹陷中、新生代热史及烃源岩热演化

查干凹陷是内蒙古银-额盆地最具勘探潜力的凹陷, 为了揭示查干凹陷中、新生代热史及烃源岩热演化历史, 首先利用9口井的镜质体反射率数据恢复了查干凹陷中、新生代热史, 结果显示查干凹陷在早白垩世巴音戈壁组沉积开始至银根组沉积末期, 地温梯度逐渐增加, 且到银根组沉积末期达到最大, 为50~58 ℃/km; 自晚白垩世乌兰苏海组沉积开始至今, 地温梯度逐渐下降, 现今地温梯度仅为31~34 ℃/km.再以热史为基础, 结合沉积和构造发育史及烃源岩地球化学资料, 模拟了查干凹陷9口井3套烃源岩的成熟度演化历史, 模拟结果显示查干凹陷烃源岩成熟度演化受古地温控制, 3套烃源岩成熟度都在早白垩世晚期达到最大.      

银额盆地苏红图坳陷西部中生界烃源岩热演化史恢复

苏红图坳陷是位于银额盆地东北部的中生代断陷盆地,含油气资源勘探潜力较大.利用研究区7口井的75个镜质体反射率资料,分析了研究区中生界烃源岩热演化程度及分布特点,银根组烃源岩处于未成熟-低成熟阶段,苏红图组底部Ro分布在0.6%~1.2%,凹陷中心巴音戈壁组底部Ro普遍大于1.1%.苏红图坳陷西部中生代以来的热历史恢复表明,研究区现今地温梯度为34 ℃/km,晚白垩世地温梯度约为40.6~46.7 ℃/km,地温梯度从40~42 ℃/km（135~110 Ma）增加到46~50 ℃/km（110~103 Ma）,银根组沉积期（100~95 Ma）地温梯度达到最大,为48~53 ℃/km;从乌兰苏海组沉积开始到现今,地温梯度先增大到40~46 ℃/km（92~80 Ma）,后逐渐降低为34 ℃/km（80~0 Ma）.研究区早白垩世以来较高的地温场对油气生成、成藏起着重要的控制作用,烃源岩均在乌兰苏海组沉积末期达到最大热演化阶段.      

鄂尔多斯盆地南部延长组油气成藏期次研究

为了研究鄂尔多斯盆地南部延长组油气成藏期次和成藏模式,采取镜下观察、激光拉曼、显微测温等方法对盆地南部地区延长组储层成岩作用和包裹体的特征进行了研究,并结合烃源岩生烃史、盆地热演化史,综合分析研究区延长组成藏期次。研究结果表明:鄂尔多斯盆地南部地区延长组存在两期油气包裹体:第一期油气包裹体在荧光显微镜下呈蓝绿色或深绿色的液烃包裹体,丰度较低,伴生的盐水包裹体均一温度主峰为100~110 ℃;第二期油气包裹体以气液烃包裹体为主,包裹体在单偏光下为无色或淡黄色,荧光显微镜下为亮蓝色,丰度较高,伴生的盐水包裹体均一温度主峰为130~140 ℃。通过对油气包裹体的均一温度、盐度、密度研究明确了研究区为“一期两幕”成藏,结合盆地热演化史认为鄂尔多斯盆地南部地区延长组存在两次油气充注:第一次油气充注在早白垩世中期(距今115~125 Ma),第二次油气充注主要在早白垩世晚期(距今97~105 Ma)。两次油气充注表明鄂尔多斯盆地南部地区延长组油气成藏时期为早白垩世(距今97~125 Ma)。     

王集-新庄地区包裹体特征及油气成藏期次

通过采集泌阳凹陷王集-新庄地区岩心样品,对其中包裹体进行盐度特征分析、镜下观察及均一温度测定;结果表明王集-新庄地区包裹体分为两期,与盆地埋藏史和热史研究划分的早、晚两个成藏期相对应。结合生排烃史综合分析,该区油气分两期成藏,早期油气成藏期主要发生在核一段末期~廖庄组沉积期,为小规模油气成藏,该期主要生成低熟油;晚期油气成藏期主要发生在廖庄末抬升期,为大规模油气成藏,是形成现今油田的主要成藏期。利用油气包裹体进行油气成藏研究,必须和宿主矿物的矿物岩石学分析及其他成藏期次分析方法结合使用,才能使分析结果更加客观可信。     

内蒙古海拉尔盆地乌尔逊凹陷热演化史

乌尔逊凹陷是内蒙古海拉尔盆地内勘验程度较高的一个南部凹陷,该凹陷沉积厚度大,地层发育全,生油条件十分优越,是海拉尔盆地主要产油气凹陷。主要烃源岩层是南屯组,其次是铜钵庙组和大磨拐河组。根据磷灰石裂变径迹法恢复的乌尔逊凹陷早白垩世古地温梯度为3.44℃/hm,接近现今地温梯度3.3℃/hm。古地温恢复及热演化史模拟表明,乌尔逊凹陷中生代以来经历了一个升温过程,下白垩统烃源岩热演化程度主要受现今地温场控制。热演化史与油气关系研究结合伊利石测年结果表明,乌尔逊凹陷油气成藏期主要有两期,为早白垩世晚期及古近纪以来,且以早白垩世晚期为主要成藏期;古近纪以来为第二期成藏阶段,烃源岩进入第二次生油高峰期。第二次成藏时期对乌尔逊凹陷油气藏的形成起着重要作用,是制约油气富集的重要因素。     

雅布赖盆地萨尔台凹陷古地温场与油气成藏期次

为了探明雅布赖盆地萨尔台凹陷中侏罗统烃源岩经历的古地温环境及其与油气成藏的关系,利用镜质体反射率(Ro)、磷灰石裂变径迹(AFT)、流体包裹体等古温标揭示古地温大小,并建立烃源岩热演化史模型,在此基础上结合流体包裹体均一温度进行油气成藏期次判定.研究区现今为低温传导型地温场,地温梯度为2.76 ℃/100m.不同次级构造单元古地温场特征不同:盐场次凹、小湖子次凹为传导型古地温场,古地温梯度为2.8~3.4 ℃/100m,古地温约81.2℃~128.1℃;黑沙低凸起带受凸起聚热或热异常作用的影响,古地温梯度明显高于沉积凹陷区域,达到4.0~4.8 ℃/100m,古地温约103.2℃~140.2℃.中侏罗统古地温高于现今地层温度,有机质成熟演化主要受古地温场的控制.热史模拟和油气成藏期次分析表明,萨尔台凹陷不同次级构造单元油气充注过程稍有差异,但对整个萨尔台凹陷中侏罗统储层来讲主要存在两期油气充注过程,分别发生在晚侏罗世早期(145.0~152.0 Ma)和早白垩世(100.0~134.0 Ma),与达到古地温峰值的时间大致相当,体现出古地温场演化在油气成藏过程中的重要性.     

流体包裹体中盐度分析与应用——以福山凹陷为例

盐水包裹体中盐度（w（NaCl））信息与均一温度一样,是进行流体活动分析的主要依据。基于福山凹陷盐水包裹体盐度测试数据并结合均一温度等信息,对福山凹陷流体包裹体的幕次组合及成藏期流体的幕式活动特征进行了分析。结果表明：福山凹陷烃类包裹体荧光色丰富,均一温度单一峰值,盐水包裹体盐度具有先下降后上升再下降的变化特征;其流体包裹体可划分为7个幕次组合,即福山凹陷古近系存在着7幕流体活动,早2幕为排烃早期流体活动,中间3幕为成藏期流体活动,后2幕为异常热流体活动。分析还得出：福山凹陷具有多幕成藏、多源混注的成藏特征,成藏时期为13~6 Ma,油气主充注幕次对应于生排烃高峰;异常热流体活动时期晚于成藏期,且异常热流体活动是导致地层水盐度中途突然升高的主因。     

包裹体测温技术在高邮凹陷北斜坡戴南组油气成藏期中的应用

为确定高邮凹陷北斜坡戴南组油藏的成藏期次,采用流体包裹体测温技术,对研究区3口井的流体包裹体特征和均一温度进行了分析。结果表明,该区戴南组储层流体包裹体分为盐水包裹体和有机包裹体;均一温度呈1期连续分布,主峰温在90～100℃。根据包裹体均一温度、地层埋藏史和热史,推测该区戴南组油气成藏时对应的地质年代约为垛二段沉积末期。结合圈闭发育史和烃源岩生排烃史等分析,最终确定研究区戴南组为1期成藏,时间为垛二段沉积末期。     

海拉尔盆地呼和湖凹陷下白垩统烃源岩地球化学特征及热演化史

呼和湖凹陷下白垩统烃源岩生油条件好,油气资源潜力大.利用研究区7口钻井270个热解资料和125个镜质体反射率数据,分析了下白垩统烃源岩地球化学特征及热演化史.下白垩统烃源岩有机质类型主要为Ⅲ-Ⅱ2型干酪根,现今热演化程度具有中间高、四周低的特点.主力烃源岩层南屯组属于中等-好烃源岩,在约128 Ma进入生烃门限,现今处于高成熟-生气阶段.大磨拐河组属于差-中等烃源岩,在约124 Ma进入生烃门限,现今处于中等-低成熟阶段,大磨拐河组二段烃源岩至今未进入生烃高峰.热史模拟表明呼和湖凹陷在伊敏组沉积晚期达到最大古地温,地温演化具有先升高后降低的特点.从南屯组沉积至今,地温梯度先升高到50~55℃/km,后逐渐降低为现今的35.4℃/km.早白垩世以来较高的地温场对油气生成、成藏起控制作用.包裹体均一温度结合热演化史结果表明126~87 Ma（伊敏组沉积时期）应是呼和湖凹陷油气主成藏期.晚白垩世以来盆地发生抬升,温度降低,烃源岩生烃强度减弱.      

蠡县斜坡北段储层流体包裹体特征及成藏时期

饶阳凹陷西部蠡县斜坡是在前古近纪古隆起上发育起来的继承性宽缓沉积斜坡,沙河街组储层发育烃类和盐水包裹体。通过储层流体包裹体的系统分析和均一温度-精细埋藏史投影,确定蠡县斜坡北段沙一下亚段油气成藏期次和时期,为分析成藏过程及油气分布规律、指导油气勘探提供了依据。蠡县斜坡北段沙一下亚段地质历史时期发生过2期油气充注:发黄绿色荧光的油包裹体均一温度在80~90℃之间,对应的成藏时间在7.5~5.5 Ma之间;发蓝绿色荧光的油包裹体均一温度在105~115℃之间,成藏时间在2~0 Ma之间。     

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.     

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.)     

GEOCHEMISTRY

正20142002 Wei Hualing(Institute of Geophysical and Geochemical Exploration,Chinese Academy of Geological Sciences,Langfang065000,China);Zhou Guohua Element Content and Mineral Compositions in Different Sizes of Soil in Tongling Area,Anhui Province(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(11),2013,p.1861