松辽盆地敖古拉断裂的封烃泄水作用   总被引：3，自引：0，他引：3  

吕延防  王亚春 《地球科学进展》2004,(Z1)

敖古拉断裂位于齐家一古龙坳陷生油气区向西运移的指向上。且其走向与油气运移方向垂直。该断裂自基底一直断到第四系。具同生正断特征。通过封堵率计算研究表明,该断裂的侧向封烃能力在姚家组和泉头组地层中为中等,在嫩江组和青山口组地层中较好。通过断面压力计算发现,该断裂垂向封闭性在浅部差,深部好;在断裂走向上断裂中部差。向两端逐渐变好。通过地层水矿化度和变质系数等参数的分布规律及一系列折算水位剖面图的分析发现。该断裂对水是不封闭的,并且是盆地西缘大气渗入水向东流动(向心流)及齐家—古龙坳陷沉积压实水向西流动(离心流)的共同泄水带。所以,该断裂是一条封烃泄水断裂。敖古拉断裂封烃泄水的主要机理是毛细管压力作用。由于敖古拉断裂的封烃泄水作用,使其对齐家—古龙坳陷向西运移的油气起到了一定的屏障作用。  相似文献   

Alkane Biomarkers in Permian—Triassic Boundary Strata at Meishan Section, Changxing, Zhejiang Province   总被引：1，自引：0，他引：1  

LuLiqiang TongJinnan 《中国地质大学学报(英文版)》2002,13(2):177-181

Meishan Section D in Changxing County, Zhejiang Province, China has been selected as the global stratotype of the Permian-Triassic boundary and various studies hav been done at the boundary but the gas chromatographic-mass spectrographic analysis of alkane biomarkers has not been investigated. This paper presents of results of a study of the biomarkers analyzed in a series of samples across the permian-Triassic boundary at both Meishan Section A and Section D. The results show that the overall concentration of alkane biomarkers in the Permian-Triassic boundary strata is high in Bed 26 while it is low in Bed 27. A variety of biomarker parameters demonstrate that the main sources of organic matter in the sediment are algae and bacteria and that the depositional enviroment varied from weakly oxidizing to reducing during the studied interval.  相似文献   

基于时域有限差分法的雪花粒子群多次散射研究     

谢槟泽  王金虎  蔡嘉晗  陈浩  王佳欣  李晶 《气象科技》2020,48(3):313-321

为精确利用雷达回波反演雪花粒子的微物理参数,建立满足指数分布的非球形雪花粒子群模型,在94GHz频率下利用XFDTD软件计算电磁波不同入射方向下粒子群的后向散射截面,并与简单相加作比较,结果表明:同一入射方向下,粒子群多次散射效应下的后向散射截面均大于简单相加的结果;不同入射方向下,粒子群的后向散射截面表现出很大的差异。因此雷达实际探测中必须考虑多次散射和入射电磁波的方向。  相似文献   

Ophiceras(蛇菊石)在滇东卡以头组的发现及其意义     

田云涛  喻建新  冯庆来 《地层学杂志》2008,32(2):153-158

Ophiceras(蛇菊石)在滇东海陆交互相卡以头组下部(25层下部)的首次发现,是近期海陆交互相和陆相二叠系-三叠系界线(PTB)研究的重要进展之一。该化石的发现为滇东卡以头组地层时代的确定提供了更加确凿的依据。在煤山D剖面,29-37层为Ophiceras(蛇菊石)的顶峰带,因此,可将滇东密德B剖面的25层与煤山D剖面29层对比,那么滇东地区卡以头组主体(甚至全部)的时代可划归早三叠世。  相似文献   

哀牢山北段金矿成矿地质条件     

刘天国 《云南地质》2008,27(3):302-308

哀牢山北段发现诸多金矿,其中,以接触蚀变带型、破碎带蚀变岩型、火山碎屑岩型为主,构造及超基性岩控制金成矿,硅化、黄铁矿化、铬云母化为找矿标志。  相似文献   

Grain-size characteristics of sediments formed since 8600 yr B.P. in middle reaches of Yarlung Zangbo River in Tibet and their paleoenvironmental significance     

Yinghua Zheng  Yongqiu Wu  Sen Li  Lihua Tan  Shiwei Gou  Hongyan Zhang 《中国地理科学(英文版)》2009,19(2):113-119

Widespread aeolian sediments have been found in the middle reaches of the Yarlung Zangbo River, China. The grain-size characteristics of sediments from Cha'er Section in the area were analyzed. The results show that the section include one stratum of paleo-mobile dunes, four strata of paleo-semi-fixed dunes, two strata of paleo-fixed dunes, one stratum of sandy immature soils. The paleo-mobile and paleo-somi-fixed dune sand in this section are similar to modern aeolian sand in either grain-size composition or Mz and σ distribution. Compared the above types of dunes each other, the content of sand substance decreases, while the content of silt and clay increases for palco-fixed dunes and sandy immature soils. Combined with age data for each stratum, the analysis shows that these strata are the products of climate changes and the evolution of aeolian landforms. The evolutionary sequence of the paleoclimate and of acolian activities in the valley since 8600 yr B.P. reveals four stages: 8600-5700 yr B.P., when the paleoclimate was cold and dry, with strong winds, thereby activating dunes; 5700-3600 yr B.P., when it was warm and wet, with weak winds, causing dunes to undergo soil-forming processes; 3600-1900 yr B.P., when climate shifted from cold-dry with strong winds to warm-wet with weak winds, and activated dunes were fixed again; and 1900 yr B.P. -present, when the climate became fine, with weak winds, fixing dunes again.  相似文献   

马鞍石热电厂灰坝稳定性分析与地质灾害防治     

闫振 《内陆地震》2008,22(2):177-181

为了对马鞍石热电厂灰坝工程做出安全性评价,对坝体在无渗水作用下可能发生的地质灾害进行了分析。选取坝体可能破坏的面进行理论计算,发现其安全系数值大于规范给定的数值,大坝是稳定的。经现场勘察及相应分析,该坝汇水面积较大,若不加整治,由强降雨引起的汇流雨水对坝体稳定造成一定的威胁,因此,提出了相应措施对大坝进行整治。  相似文献   

Fossil gastropods from the MGS3 stratigraphic segment in the Salawusu River Valley and their climatic and environmental implications     

Li BaoSheng  Chen DeNiu  David Dian Zhang  Wen XiaoHao  Qiu ShiFan  Ou XianJiao  Du ShuHuan  Niu DongFeng  Yang Yi  Ye JianPing  Guo YunHai 《中国科学D辑(英文版)》2008,51(3):339-348

Contemporaneous with MIS3, the MGS3 segment of the Milanggouwan stratigraphic section in the Salawusu River Valley, Mu Us Desert, China contains fossil gastropods (terrestrial and freshwater snails) in strata 33LS, 35LS, 37FL and 39LS. Examination of these fossils revealed 11 species belonging to 8 families and 10 genera. They can be classified as: (1) assemblage of Gyraulus and Galba mainly consisting of Gyraulus convexiusculus, Gyraulus sibiricus, Galba pervia and Galba superegra Gredler, etc. (2) assemblage of Vallonia mainly consisting of terrestrial snails, such as Vallonia patens, Pupilla muscorum and Discus paupe, etc. Based on the dating results, and the living habits, living conditions, and geographic distribution of their extant species, we suggest that: the ages of 33LS, 35LS, 37FL, and 39LS are 26000, 29000, 33000 and 38000 a, respectively, corresponding well to the interstadial period in GRIP 4, 5, 6 and 10 in terms of chronology and climatic characters; 33LS, 35LS and 39LS represent very warm-humid periods, while 37FL represents a less warm-humid period; the four periods of climatic fluctuations recorded in MGS3 were related to the strong impact of the summer monsoon in East Asia in Mu Us Desert of China during the interstadial of MIS3 on a global climatic background.  相似文献   

蓝细菌微生物席主导的芙蓉统均一石生物丘:以河北涞源祁家峪剖面为例   总被引：1，自引：0，他引：1  

梅冥相  MUHAMMADRiaz  刘丽  孟庆芬 《地质论评》2019,65(5):1103-1122

基于中等尺度的构造特征,常常将微生物碳酸盐岩划分为四个类型：纹层状的叠层石、凝块状的凝块石、贫乏构造的均一石、树枝状的树形石;在其中,均一石被定义为相对贫乏构造和非晶质的中等构造,而且作为“隐秘微生物”的同义语曾经与凝块石相混用。华北地台的芙蓉统,包括长山组和凤山组,可以进一步划分为3个淹没不整合面型三级沉积层序;在这些三级层序的强迫型海退体系域中,常常集中产出各种微生物碳酸盐岩所主导的生物丘,河北涞源祁家峪剖面的芙蓉统就是一个较为典型的实例。在该剖面,两套较为典型的均一石生物丘灰岩构成了较为壮观的沉积学现象,其内部特别的非均一组构与贫乏构造的宏观特征形成了强烈的反差,从而将这些均一石生物丘特征化,包括：① 钙化蓝细菌化石如基座菌、葛万菌,以及可以类比于第谷菌的丝状蓝细菌鞘化石;② 底栖鲕粒;③ 肾型菌状的钙化生物膜残余物;④ 海绵木乃伊;⑤底栖鲕粒填充的生物潜穴;⑥包覆着海绵木乃伊和生物潜穴的微叠层石。这些特征,表明了这些均一石生物丘可能形成于蓝细菌细胞外聚合物质（EPS）复杂的钙化作用,而且这样的EPS是蓝细菌微生物席及其内部的多重状生物膜的基本有机基质构成。由于均一石缺乏现代可以类比的典型实例,而且在其命名之后也很少描述在在古老的地层记录中,所以,河北涞源祁家峪剖面芙蓉统中的均一石生物丘为了解均一石形成的复杂机理提供了一个最为典型的实例。  相似文献   

长江三峡巫山第四纪沉积物粒度分布特征     

黄臻  王建力  王勇 《热带地理》2010,30(1)

以长江三峡巫山第四纪沉积物为主要研究对象,目的在于弄清它究竟是风化壳还是北方黄土在此区的沉积。利用马尔文激光粒度仪对其粒度进行了检测,并计算了粒度参数,结果表明:(1)砂含量极少,平均值为0.7﹪,粉砂最高,为68.64﹪,黏粒次之,为30.66﹪;风尘基本粒组10~50μm含量较高,平均值为52.07﹪,推测其成因有一定的风成特性。(2)剖面粒度分布曲线呈单峰形态,拖有细尾,与风成黄土类似,可能指示沉积后经历了风化成壤作用。(3)望天坪剖面粒度参数特征与北方风成黄土具一定相似性,判别参数分析对应于风成成因。根据以上分析,初步判定其物源具风成特性,但其环境意义还有待进一步探讨。  相似文献