基于高分辨率瞬时信息与相干算法的低幅度构造识别     

李鹏  刘财  冯晅  鹿琪  王典  王世煜 《地球物理学进展》2013,28(1):394-401

随着勘探程度的深入,隐蔽圈闭,尤其是低幅度构造油气藏逐渐受到关注,其在地震资料上表现为反射同相轴平直且变化幅度很小,不易识别.利用相干算法识别低幅度构造,确定出了薄互层低幅度构造的空间展布;经过高分辨率复数道分析处理,提高了剖面分辨率,利用高分辨率瞬时振幅、相位、频率剖面的各自特性识别出了薄互层低幅度构造的构造异常点,此基础上再结合相干算法识别低幅度构造,精度更高.  相似文献   

经济快速发展背景下中国民用汽车拥有量变化的时空特征     

杨昆  时燕  罗毅  夏典 《地理科学》2019,39(4):654-662

基于统计数据,采用Theil指数、线性倾向率、Mann-Kendall（M-K）检验、面板数据模型,从中国、八大经济区域、各省3个尺度分析中国民用汽车拥有量的时空变化特征及其与地区生产总值、居民消费水平、公路里程的关系。结果表明：① 中国民用汽车拥有量的增长分两个阶段： 1996~2005年为缓慢增长期,2005~2015年为快速增长期;② 2000~2015年中国民用汽车拥有量地区分布差异显著下降,2000~2005年区域内总差异是总差异的主要成分,北部沿海地区区域内差异是区域内总差异的主要原因,2006~2015年区域间差异是总差异的主要成分;③ 在不同的时间阶段及空间尺度各因素对民用汽车拥有量发展的作用方向和作用强度呈现一定的差异性。  相似文献   

新疆哈尔里克早石炭世A型花岗岩的岩石成因及构造意义     

王良玉  廖群安  肖典  罗婷  赵浩  刘鸿飞  王国灿 《地质力学学报》2016,22(4):1032-1048

对出露在哈尔里克山西段小白杨沟-南山口一带的早石炭世花岗岩进行了锆石LA-ICP-MS U-Pb定年,结果为331.3±1.9 Ma,属早石炭世晚期。其岩石组合为碱长花岗岩、碱性花岗岩,暗色矿物以黑云母为主,见钠质角闪石,具富碱、贫钙镁和低铝铁的特征,微量元素明显富集Rb、Th、K等大离子亲石元素和Zr、Hf等高场强元素而强烈亏损Ba、Sr、Eu等元素,10000 Ga/Al值变化于2.93~3.80之间,表明该碱性花岗岩属于典型的A型花岗岩,具板内花岗岩特征,并非前人认为的岛弧花岗岩,其正εNd（t）值（+5.66~+6.12）和年轻的Nd模式年龄（T_DM2=0.60~0.62 Ga）显示岩浆来源于新生年轻地壳。从本次1:50000区调研究成果看,博格达自早石炭世开始伸展,早石炭世晚期进入闭合阶段,哈儿里克山早石炭世晚期岩体应处于博格达裂谷晚期阶段,并非前人所说的后碰撞和岛弧环境。   相似文献   

基于非平稳相似性系数的构造导向滤波及断层检测方法   总被引：3，自引：2，他引：1       下载免费PDF全文

刘洋  王典  刘财  刘殿秘  张鹏 《地球物理学报》2014,57(4):1177-1187

不连续地质体（如断层）的自动检测一直以来都是叠后地震数据解释中的关键问题之一,尤其在三维情况中尤为重要.然而,大多数边缘检测和相干算法都对随机噪声很敏感,随机噪声衰减是叠后地震数据解释的另一个主要问题.针对构造保护去噪和断层检测问题,本文基于非平稳相似性系数完善一种构造导向滤波方法并且提出一种自动断层检测方法,形成了一套匹配的处理技术.该构造导向滤波既能够有效地衰减随机噪声又可以很好地保护地震资料中的断层等信息不被破坏,增强地震剖面中弯曲、倾斜同相轴的连续性.根据地震数据局部倾角走向,利用相邻道构建当前地震道的预测,通过预测道的叠加得到参考道,计算预测道与参考道之间的非平稳相似性系数可以设计出数据驱动的加权中值滤波.另一方面,预测道与原始道之间的非平稳相似性系数能够用于带有断层指示性的相干分析.这两种方法都基于构造预测和非平稳相似性系数,但是使用不同的调节参数和处理方案.理论模型和实际数据的处理结果证明了本文提出构造导向滤波和断层检测方法的有效性.  相似文献   

Fuzzy probabilistic seismic hazard analysis with applications to Kunming city,China     

Jelena M. Andrić  Da-Gang Lu 《Natural Hazards》2017,89(3):1031-1057

China is prone to highly frequent earthquakes due to specific geographical location, which could cause significant losses to society and economy. The task of seismic hazard analysis is to estimate the potential level of ground motion parameters that would be produced by future earthquakes. In this paper, a novel method based on fuzzy logic techniques and probabilistic approach is proposed for seismic hazard analysis (FPSHA). In FPSHA, we employ fuzzy sets for quantification of earthquake magnitude and source-to-site distance, and fuzzy inference rules for ground motion attenuation relationships. The membership functions for earthquake magnitude and source-to-site distance are provided based on expert judgments, and the construction of fuzzy rules for peak ground acceleration relationships is also based on expert judgment. This methodology enables to include aleatory and epistemic uncertainty in the process of seismic hazard analysis. The advantage of the proposed method is in its efficiency, reliability, practicability, and precision. A case study is investigated for seismic hazard analysis of Kunming city in Yunnan Province, People’s Republic of China. The results of the proposed fuzzy logic-based model are compared to other models, which confirms the accuracy in predicting the probability of exceeding a certain level of the peak ground acceleration. Further, the results can provide a sound basis for decision making of disaster reduction and prevention in Yunnan province.  相似文献   

Climate variability in the Salawusu River valley of the Ordos Plateau (Inner Mongolia,China) during Marine Isotope Stage 3   总被引：1，自引：0，他引：1  

Xiaohao Wen  Baosheng Li  Yanming Zheng  David Dian Zhang  Jianping Ye 《第四纪科学杂志》2009,24(1):61-74

Fluctuations in climatic proxies of the Milanggouwan section in the Salawusu River valley of the Ordos Plateau (Inner Mongolia, China) during Marine Isotope stage 3 (MIS 3) coincide well with sedimentary cycles for palaeo‐mobile dune sands alternating with fluvial–lacustrine facies and palaeosols. We compared the palaeo‐mobile dune sands with modern mobile dune sands (products of a cold and dry climate dominated by the East Asian winter monsoon), whereas the fluvial–lacustrine facies and palaeosols were controlled by a wet–warm climate similar to that of the East Asian summer monsoon. The MIS 3 climate of the Salawusu River valley appears to have experienced at least nine wet–warm and ten cold–dry fluctuations, divided into five stages: MIS 3e (58 900–49500 yr BP), MIS 3d (49 500–40 700 yr BP), MIS 3c (40 700–36 900 yr BP), MIS 3b (36 900–27 000 yr BP) and MIS 3a (27 000–22 300 yr BP). The 19 cold–warm climatic fluctuations corresponded roughly to the GRIP and Guliyan records, and with fluctuations in the North Atlantic climate. Notable peaks in the spectral analysis occurred at 19 500 yr, 1020 yr, 640 yr and 500 yr. Our results show that the millennial–centennial climate was closely related to the relative strengths of East Asian monsoons, which are controlled by the North Atlantic thermohaline circulation, and which is also closely linked to the Sun's precession period. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

新疆库地南苏盖提力克晚志留世花岗岩锆石U-Pb年龄、地球化学特征及大地构造意义     

专少鹏  白春东  毛志芳  李典  张新征  陈圆圆  连青 《地质力学学报》2018,24(5):661-669

西昆仑地区早古生代原特提斯洋的后碰撞阶段划分存在分歧,通过对库地蛇绿岩南侧苏盖提力克花岗岩开展区域地质调查、岩石学、地球化学、锆石U-Pb年代学等方面研究,从而为原特提斯洋构造演化及闭合时限提供地质依据。研究表明,苏盖提力克花岗岩锆石U-Pb年龄（LA-ICP-MS）为（422.5±2.5）Ma,属于晚志留世岩浆活动产物。苏盖提力克花岗岩含有典型矿物白云母,A/CNK=1.07~1.11,刚玉分子含量为1.07%~1.56%,属于S型花岗岩。地球化学上,该岩体富硅、碱,贫钙、镁,富K、Rb、Nb、Th,贫Sr、Ti、P,Rb/Sr比值高;结合区域地质背景及地球化学特征综合分析表明,苏盖提力克花岗岩是原特提斯洋闭合后碰撞阶段的产物,因而晚志留世是原特提斯洋由消减闭合到陆陆碰撞—碰撞后伸展转换时期。   相似文献   

雅鲁藏布江航磁异常带性质及其意义   总被引：5，自引：6，他引：5  

姚正煦  周伏洪  薛典军  刘振军  张永军 《物探与化探》2001,25(4):241-252

航磁概查发现雅鲁藏布江航磁异常带东西相连长达1400km,它由北、南2条线性异常带构成,并认为它由沿雅鲁藏布江缝合带侵位的北、南2条蛇绿岩带引起,且以北带为主,即雅鲁藏布江缝合带是由2条蛇绿岩带组成,而不是过去地学界所认同的一条。航磁异常带实质上是雅鲁藏布江缝合带存在的客观反映,不仅为识别缝合带提供了比较典型的磁场模式,也为探讨新特提斯洋演化、可能存在2次开合过程,提供了新的依据。  相似文献   

Study of Sediments in the Yutian-Hotan Oasis, South Xinjiang, China   总被引：2，自引：0，他引：2  

LI Baosheng  David Dian ZHANG  ZHOU Xingjia  ZHU Feng  YUAN Baoyin  MU Guijin  LI Sen  YAN Mancun  JIN Heling  GAO Quanzhou  SUN Wu 《《地质学报》英文版》2002,76(2):221-228

Based on investigation of sediments in the Yutian-Hotan Oasis at the southern margin of the Tarim basin, 14C ages and grain-size and chemical element analyses, the following views are put forward in this paper.(1) Sediments in the Yutian-Hotan Oasis are composed chiefly of "oasis soil", similar to the recent oasis soil, i.e. brown desert soil, which was formed due to pedogenesis after aeolian sand (sandy loam) and dust (loess) of 3.32-6.64 were deposited.(2) The ancient Yutian-Hotan Oasis represented by oasis soil was formed at 13000 a B.P. During the cold period of the past 13000 years, this region is characterized mainly by accumulation of sand and dust storms, and sandy oasis soil was developed in this region due to pedogenesis in an oasis environment; during the warm period, dust falls predominated along with certain current concomitants (lacustrine facies), and silty oasis soil was formed by pedogenesis. Owing to fluctuations of cold and warm climates since 13000 a B.P., sandy oasis soil was deposi  相似文献   

青藏高原的大气CO_2含量、岩溶溶蚀速率及现代岩溶微地貌   总被引：8，自引：0，他引：8  

章典  师长兴 《地质学报》2002,76(4):566-570

青藏高原是世界上最高、最大和最年青的高原。按照气候地貌学的观点,其干燥和寒冷的气候条件不利于岩溶地貌的发育。笔者在青藏高原上已发现了广泛分布的岩溶微形态。笔者用国际通用的石灰岩圆形切片,在西藏三个不同地点进行了12年的野外溶蚀试验,揭示出青藏高原的岩溶溶蚀速率是全世界最低的,在土层中还产生沉淀现象。通过在青藏高原不同高程上测量大气中CO_2分压,发现P_(CO_2)随海拔高度的增加而降低。在土壤、沉积物和岩石裂隙中的P_(CO_2)也呈现同样的变化趋势。由于CO_2含量直接影响天然水的溶蚀能力,因此可以断定低CO_2浓度是造成青藏高原上现代岩溶过程微弱的重要原因之一。其他主要原因包括干旱和寒冷气候条件。通过对不同微地貌上溶蚀速率的计算和形态分析,可以认为,分布于高原面上的所有岩溶微形态中,现代发育的岩溶微地貌形态仅仅是那些与生物岩溶过程有关的溶痕,其他岩溶微地貌形态可能是全新世温暖期的产物。  相似文献