塔里木盆地东北缘库鲁克塔格地区的早古生代地壳变形以及造山时限

位于中亚造山带与塔里木克拉通结合部位的新疆库鲁克塔格是研究中亚造山带及塔里木克拉通关系的一个关键地区。野外观测、显微构造分析以及Ar–Ar测年结果揭示:(1)库鲁克塔格地区震旦纪—早古生代岩系地层变形样式为底部强烈褶皱,面理密集向北缓倾,顶部褶皱较宽缓、劈理稀疏向北陡倾,构成具有向南构造指向的铲式构造样式;(2)库鲁克塔格地区基底与盖层之间存在一条E–W走向、厚度约2 km的韧性滑脱带,带内普遍发育糜棱岩及A型剪切褶皱等,糜棱岩面理向N或S缓倾、拉伸线理向NW或SE倾伏,不对称旋转构造及糜棱岩中石英晶格优选方位图(EBSD测试)指示韧性滑脱带上盘滑脱方向为自NW向SE;(3)韧性滑脱带中糜棱岩内白云母的Ar–Ar测年结果表明滑脱时代早于383 Ma。滑脱–褶皱构造是塔里木地块与中天山岩浆弧带碰撞后发生陆内俯冲的产物,说明塔里木盆地东北缘库鲁克塔格存在早古生代造山事件。     

卡姆斯特煤田侏罗系八道湾组地层层序及聚煤特征

综合利用卡姆斯特煤田钻孔测井、野外露头及古生物化石等资料,应用经典层序地层学基本理论和方法,对卡姆斯特煤田八道湾组进行了层序地层划分,共识别出SQ1和SQ2两个三级层序,并根据地层叠置样式、沉积旋回特征细分为6个体系域。通过沉积基础图件、沉积环境的分析明确了研究区八道湾组沉积演化主要受古地形起伏、古气候条件等古地理因素的综合影响。确定研究区内目的层段主要在高位和低位时期聚煤,湖侵时期不利于聚煤。通过详细研究卡姆斯特煤田八道湾组的沉积环境和聚煤特征,为今后寻找和开发卡姆斯特地区煤炭资源提供地质依据。     

中天山东部南北两缘韧性剪切带变形特征

(1)中天山北缘韧性剪切带除右旋韧剪变形之外,还发育相对较弱的左旋韧剪变形,局部残留加里东晚期的逆冲推覆韧剪变形;右旋韧剪变形的变形温度环境为中-低温,左旋韧剪变形的变形温度环境为高温、中温、中低温及低温。(2)中天山南缘韧性剪切带以右旋韧剪变形为主,兼具左旋韧剪变形;右旋韧剪变形的变形温度环境为中温、中低温、低温,左旋韧剪变形的变形温度环境为高温、中温、中低温及低温。(3)东天山存在一系列右旋韧性剪切带,中天山南北两缘韧性剪切带的构造变形与辛格尔断裂、兴地断裂等右旋韧性剪切带的变形以及塔里木北缘东部晚震旦—早古生代地层的同劈理褶皱变形、南天山泥盆纪地层的变形可能具成因联系。     

Gravity Flow on Slope and Abyssal Systems in the Qiongdongnan Basin, Northern South China Sea

The study of new seismic data permits the identification of sediment gravity flows in terms of internal architecture and the distribution on shelf and abyssal setting in the Qiongdongnan Basin (QDNB). Six gravity flow types are recognized: (1) turbidite channels with a truncational basal and concordant overburden relationship along the shelf edge and slope, comprising laterally-shifting and vertically-aggrading channel complexes; (2) slides with a spoon-shaped morphology slip steps on the shelf-break and generated from the deformation of poorly-consolidated and high water content sediments; (3) slumps are limited on the shelf slope, triggered either by an anomalous slope gradient or by fault activity; (4) turbidite sheet complexes (TSC) were ascribed to the basin-floor fan and slope fan origin, occasionally feeding the deep marine deposits by turbidity currents; (5) sediment waves occurring in the lower slope-basin floor, and covering an area of approximately 400?km2, were generated beneath currents flowing across the sea bed; and (6) the central canyon in the deep water area represents an exceptive type of gravity flow composed of an association of debris flow, turbidite channels, and TSC. It presents planar multisegment and vertical multiphase characteristics. Turbidite associated with good petrophysical property in the canyon could be treated as a potential exploration target in the QDNB.     

Late Silurian to Early Devonian Palynomorphs from Qujing, Yunnan, Southwest China

Well-preserved and diversified spores, cryptospores, and acritarchs have been recorded from a relatively continuous sequence that encompasses the Silurian–Devonian boundary in Qujing, Yunnan, southwest China. Four spore assemblage zones from Late Silurian to Early Devonian in age are proposed based on the first appearance datum (FAD) of characteristic spore species. In ascending stratigraphic order, they are Ambitisporites dilutus–Apiculiretusispora synorea (DS; Late Ludfordian to Early Pridoli), Synorisporites verrucatus–Apiculiretusispora plicata (VP; Pridoli), Apiculiretusispora minuta–Leiotriletes ornatus (MO; Lochkovian), and Verrucosisporites polygonalis–Dibolisporites wetteldorfensis (PW; Pragian). The acritarch assemblage from the upper part of the Yulongsi Formation, the Xiaxishancun Formation, and the lower–middle parts of the Xitun Formation indicates an age of Late Silurian. Based on palynological evidence, the upper part of the Yulongsi Formation is considered Late Ludfordian to Early Pridoli in age; the Xiaxishancun Formation is believed to be Pridoli in age; the Xitun Formation is considered Late Pridoli to Early Lochkovian in age; the Guijiatun Formation is considered Lochkovian in age; and the Xujiachong Formation is Late Lochkovian to Pragian in age. The Silurian-Devonian boundary is recognized between the VP and the MO spore biozones, and occurs within the middle part of the Xitun Formation.     

青海玉树东莫扎抓铅锌矿床围岩蚀变和黄铁矿-闪锌矿矿物学特征及意义

青海玉树地区的东莫扎抓铅锌矿床是"三江"沉积岩容矿贱金属成矿带中的重要矿床之一.矿区过去研究鉴定出多种蚀变类型和矿物种类,但不同蚀变在矿区的空间分布特征、不同矿物中元素含量特点、矿物相互之间的时间和空间关系均不清楚,从而导致所指示的找矿意义也不明确.为此,作者进行了系统岩矿石光薄片的显微镜下鉴定、矿区主要硫化物--黄铁...     

浅埋大跨小净距隧道断面形态及合理间距的优化研究

对于大跨度小净距隧道而言,合理扁平率及双洞间距的设计对于节约成本,提高隧道线型规划具有至关重要的作用,因此,优化大跨度小净距隧道的扁平率及其间距是隧道设计施工面临的关键问题。利用大型有限元分析软件ABAQUS的标准设计语言Python编程,对某拟建大跨度小净距隧道不同扁平率及其间距进行参数化设计;采用精确罚函数法以及Nelder-Mead优化算法相结合的有限元优化分析计算程序,以隧道开挖面积、围岩塑性区、地表沉降和拱顶下沉等作为优化目标值,对建立的参数化模型进行计算,提出依托工程条件下扁平率及间距的最优组合。研究方法和成果对推动大断面小净距隧道的发展和应用具有重要的现实意义。     

发震断层对微、宏观震中偏离的影响分析:以新疆地区为例

大量震例表明通常情况下地震的微、宏观震中有很大的偏离,如何在震后快速正确估计微、宏观震中偏离的程度,是目前迫切需要解决的重要问题。以新疆地区为例,详细研究了新疆地区M s≥6.5级的历史地震微、宏观震中偏离与发震构造的空间分布关系。新疆地区主要的发震断层类型包括逆断层、逆冲走滑断层及走滑断层3种。针对不同的发震断层类型初步提出了根据发震构造快速估计6.5级以上强震微、宏观震中偏离的模型和方法。微、宏观震中偏离的理想方向取决于破裂的性质(如单侧破裂、双侧破裂),很难确定理想宏观震中在发震断层的确切位置,具有一定的随机性,但是地震微、宏观震中的偏离方向与新疆整体构造应力方向具有一致性,宏观震中位置一般位于发震断层上或其附近,在实际应用过程中可以认为宏观震中就在断层上。     

宜川-旬邑地区长8油层组储层特征与控制因素

宜川-旬邑地区上三叠统延长组长8油层组主要为三角洲前缘沉积环境,局部发育湖底滑塌扇体.岩心观察、薄片分析、扫描电镜及压汞测试表明,长8油层组主要为长石岩屑砂岩和岩屑长石砂岩,孔隙类型以残余原生粒间孔为主,次为长石溶孔,多为片状喉道和弯片状喉道,孔隙结构以小孔隙-微喉-细喉型与细孔隙-微喉-细喉型为主,储层非均质性强,水下分流河道、河口坝储层物性最好,分支水道最差,绿泥石环边胶结成岩相及石英次生加大胶结成岩相为有利成岩相,压实和胶结作用分别损失的孔隙度为25.65%和3.31%,溶蚀作用整体新增0.83%孔隙度,形成长8油层组目前低孔-超低孔致密砂岩储层.     

松辽盆地北部泉头组三、四段储层质量预测

为了预测松辽盆地北部泉头组三、四段低渗透储层的质量,首先将碎屑岩的成岩作用细分为早成岩阶段A、早成岩阶段B期、中成岩阶段A1亚期、中成岩阶段A21、A2、中成岩阶段B期。统计结果表明,成岩作用对储层的物性和含油性具有明显的控制作用,处于中成岩阶段B期的任何沉积相的砂体均不能产出工业油气流,在中成岩阶段A22只有主河道砂...