南海沉积物中甲烷水合物的实验研究     

刘峰  吴时国  董冬冬 《海洋科学集刊》2010,50(50):139-148

The experimental apparatus for gas hydrate in porous sediments is introduced.Under different constant temperature(1.0℃,2.0℃,4.0℃,7.0℃,10.℃),the formation and dissociation of methane hydrate with three kinde of sediments granule(average diameters 0.15mm,0.06mm,0.03mm respectively) are studied. The saturation of methane hydrate in porous sediments is got by measuring the consumption of methane in vesssel. The results find that the saturation increases as formation pressure and porosity of sediments increase. It is also showed that the P-T curve in distilled water,which is accordant with the results from other papets sediments departure to left comparing to the P-T curve in distilled water, which is accordant with the results from other papers involved .  相似文献   

Characteristics and Formation Mechanism of Polygonal Faults in Qiongdongnan Basin,Northern South China Sea     

Sun Qiliang  Wu Shiguo  Yao Genshun  LI Fuliang 《中国地质大学学报(英文版)》2009,20(1)

Based on high-resolution 3D seismic data,we document the polygonal faults within the Miocene Meishan (梅山) Formation and Huangliu (黄流) Formation of the Qiongdongnan (琼东南)basin,northern South China Sea.Within the seismic section and time coherent slice,densely distributed extensional faults with small throw and polygonal shape were identified in map view.The orientation of the polygonal faults is almost isotropic,indicating a non-tectonic origin.The deformation is clearly layer-bounded,with horizontal extension of 11.2% to 16%,and 13.2% on average.The distribution of polygonal faults shows a negative correlation with that of gas chimneys.The development of polygonal faults may be triggered by over-pressure pore fluid which is restricted in the fine-grained sediments of bathyal facies when the sediments is compacted by the burden above.The polygonal faults developed to balance the volumetric contraction and restricted extension.The product of hydrocarbon in the Meishan Formation may have contributed to the development of the polygonal faults.In the study area,it was thought that the petroleum system of the Neogene post-rift sequence is disadvantageous because of poor migration pathway.However,the discovery of polygonal faults In the Miocene strata,which may play an important role on the fluid migra-tion,may change this view.A new model of the petroleum system for the study area is proposed.  相似文献   

基于RS、GIS技术的扎龙沼泽湿地景观格局变化分析   总被引：19，自引：2，他引：17  

韩敏  孙燕楠  许士国  唐晓亮 《地理科学进展》2005,24(6):42-49

本文以1986年、1999年、2002年的扎龙区域Landsat TM影像为数据源,利用RS、GIS技术分析了扎龙地区沼泽湿地16年的空间格局变化。选取景观破碎化指数、分形维数、分布质心等景观指数进行计算分析,同时研究了不同地区中沼泽湿地面积相对于总的沼泽湿地面积的变化情况。结果表明扎龙区域沼泽湿地的破碎化程度在加深,斑块形状变化不大,其质心位置向西北偏移,西北部的沼泽湿地不如东南部稳定,受到的人为影响更大。  相似文献   

裂后岩浆活动中岩床复合体的特征:以南海北部和南极西罗斯海地区为例     

张峤  高金耀  吴时国 《大地构造与成矿学》2017,41(6)

由于蕴含着潜在的油气勘探和资源储藏信息,岩床复合体在全球范围内被广泛研究。本文基于南海北部三维地震资料以及南极罗斯海地区二维多道地震资料,对岩床复合体的形态特征及分布进行分析,对两个地区岩床复合体的形成时间进行判断,阐述岩床复合体的侵位机制。研究发现,岩床复合体代表性产状除了菱形、碟形及复合型外,还存在沿着层位平行侵入的板状,推测它可能是夭折了的岩床侵入体,以及由几个小型岩床堆叠而成的透镜状岩床复合体。分布上,南海北部岩床主要发育于珠江口盆地白云凹陷三维工区西部,东部只零星可见;南极西罗斯海岩床主要发育于西北角的阿黛尔盆地内。根据岩床上覆的强制褶皱结合区域构造背景,推测南海北部岩床复合体的形成时间为早中新世(15.5 Ma),海底扩张结束之时。残余岩浆将盆地内裂谷时期形成的断层作为岩浆运移的通道,并最终在断层终点处即下中新统近海相砂泥岩地层中实现侵位。南极西罗斯海岩床复合体的形成时间则非常晚,不早于5.5 Ma。该区这期岩浆活动可能与构造作用无关,而是受到冰川消融的影响。研究发现岩床复合体内部的岩床个体互相供给,即深部的大岩床为上覆浅层的小岩床提供岩浆供给,并且互相组合,形成大的岩床复合体。然而,每个岩床复合体则可能由不同的岩浆供给发育而成。  相似文献   

美国天然气水合物研究计划介绍   总被引：9，自引：0，他引：9  

陈多福  徐文新  吴时国  宋海斌  姚伯初 《地球科学进展》2003,18(2):321-325

以美国近年来提出的天然气水合物研究计划和项目申请书为基础,介绍美国科学家在天然气水合物研究领域中所关心的关键科学与技术问题和研究焦点,供我国天然气水合物研究者在项目设计和开展研究工作时参考。美国天然气水合物研究关注的重点科学问题主要集中在 4个方面：天然气水合物的物理与化学特性研究;天然气水合物开采技术研究;天然气水合物灾害-安全性与海底稳定性研究;天然气水合物在全球碳循环中的作用研究。在研究方法上主要采取天然气水合物区的现场地质地球化学观测、实验室合成和测定及计算模拟,特别关注与水合物和油气冷泉相关的生命过程及与水合物的相互作用研究。  相似文献   

Balanced Cross Section for Restoration of Tectonic Evolution in the Southwest Okinawa Trough     

吴时国  倪祥龙  郭军华 《中国地质大学学报(英文版)》2007,18(1):1-10

On the basis of the multi-channel seismic data and the other data, using 2DMove software, the tectonic evolution in three seismic profiles was restored since Pliocene. The tectonic restoration results show that: (1) the initial active center lay in the west slope and then was transferred to east and south via trough center during the evolution process; (2) several main normal faults controlled the evolution of the southern Okinawa Trough; (3) since Late Pliocene, the southern Okinawa Trough has experienced two spreading stages. The early is depression in Early-Middle Pleistocene and the late is back-arc spreading in Late Pleistocene and Holocene, which is in primary oceanic crust spreading stage.  相似文献   

A Comprehensive Investigation of an Offshore Active Fault in the Western Sagami Bay, Central Japan   总被引：1，自引：0，他引：1  

Izumi SAKAMOTO  How Kin WONG 《《地质学报》英文版》2002,76(3):300-307

Offshore active faults, especially those in the deep sea, are very difficult to study because of the water and sedimentary cover. To characterize the nature and geometry of offshore active faults, a combination of methods must be employed. Generally, seismic profiling is used to map these faults, but often only fault-related folds rather than fracture planes are imaged. Multi-beam swath bathymetry provides information on the structure and growth history of a fault because movements of an active fault are reflected in the bottom morphology. Submersible and deep-tow surveys allow direct observations of deformations on the seafloor (including fracture zones and microstructures). In the deep sea, linearly aligned cold seep communities provide indirect evidence for active faults and the spatial migration of their activities.The Western Sagami Bay fault (WSBF) in the western Sagami Bay off central Japan is an active fault that has been studied in detail using the above methods. The bottom morphology, fracture  相似文献   

Research Progress and Challenges of Submarine Cyclic Steps     

Dawei Wang  Yue Sun  Shaowen Si  Shiguo Wu 《地球科学进展》1986,35(9):890-901

Cyclic steps structure derived from the supercritical flows is one of the common bedforms， which is commonly found in sedimentary systems such as delta systems， deep-water canyon-channel systems， and carbonate platforms. In this paper， the research progresses of cyclic steps were introduced from the aspects of sedimentary environment， the features of bedforms， sedimentary structure， formation mechanism， and numerical simulation. The Research scale differences associated with the survey techniques or study methods， such as the ship survey and AUV-based multi-beams， sub-bottom profiles， multichannel seismic， the field outcrop， and numerical simulation were discussed. Finally， the breakthrough directions of the cyclic steps research were given. The combining method of ground penetrating radar， multichannel seismic， drilling and well logging were used to accurately detect the location of field outcrop thalweg. Within the area with water depth greater than 500 meters， the blending of multi-data for the cyclic steps research involved the AUV-based and the ship multi-beams， sub-bottom profiles， and multichannel seismic data. With the in situ samples and observation data obtained by human occupied vehicles， three-dimensional numerical simulation was developed to establish a set of dynamic simulation equations suitable for the real cyclic steps. Therefore， the high resolution three dimensional mode of the deep-water cyclic steps could be obtained more accurately.  相似文献   

南极普里兹湾柱样中石英颗粒的表面结构   总被引：6，自引：0，他引：6       下载免费PDF全文

王祥珍  吴时国  李传荣  陈虹勋  罗又郎 《极地研究》1997,9(2):12-25

本文统计分析了南极普里兹湾陆坡区一个柱样（ＮＰ９５１）１３个层位的石英颗粒的形态和表面结构。石英表面呈现出强烈的冰川运动和较弱的化学溶蚀－沉淀作用留下的表面特征，表明该沉积物主要是处于低能海洋环境中的冰碛物。石英颗粒因化学溶蚀－沉淀作用形成的组合表面特征的定量统计结果与矿物的Ｘ射线衍射和微体古生物的分析结果相对应，能较好地解释该海区经历的沉积环境和古气候变化。  相似文献   

南沙海区海洋沉积学的研究进展     

罗又郎  吴时国 《地球科学进展》1995,10(2):143-147

简要介绍了中国科学南沙综合考察队有关海洋沉积学十年科考取得的研究进展，包括现代沉积作用过程，沉积地球化学，礁碳酸盐地质学，盆地分析，古海洋学与全球变化等方面。  相似文献