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81.
以钻井、测井、地震以及岩心、薄片资料为基础,在划分三级层序的基础上,探讨了渤海西南海域下古生界层序地层特征及其对岩溶储层的控制作用。结果表明:1)三级层序界面附近发育碳、氧同位素负异常以及自然能谱Th/K正异常,基于此特征将下古生界划分为21个三级层序;2)白云岩是研究区主要的储集岩性,层序通过控制垂向岩性的变化进而控制了优质储层的发育;3)将白云岩发育的12个三级层序定义为"优势储集层序",加里东期构造不整合与12个"优势储集层序"耦合控制了潜山型储层规模及其产能高低;寒武系内发育以溶蚀孔隙为主的内幕型岩溶储层,亦限定发育于"优势储集层序"之中。实际勘探中,优选风化界面与"优势储集层序"耦合区域优先钻探,同时兼顾内幕型储层,其是今后该区高效勘探的关键。  相似文献   
82.
印度尼西亚Cikotok矿区帕瑟埃拉金矿位于巽他-班达岛弧的中部Bayah穹隆中,宏观上具有找到大型矿床的地质前提.成矿围岩为始新世末-中新世早期的安山岩,围岩蚀变强烈,分带性明显,金矿脉具有多条近平行产出特征.矿床有4个成矿阶段:石英-蒙脱石-绿泥石阶段,石英-绢云母-黄铁矿阶段,石英-冰长石-硫化物-含锰矿物阶段,块状石英阶段.矿床成因类型为大洋岛弧型低硫浅成低温热液型,细分类型为"Pongkor型"条带状低硫含金石英锰氧化物矿脉型金矿,其浅表部为热泉型金矿.矿床的深部找矿潜力大,具有大型金矿的成矿潜力.  相似文献   
83.
渤海西部海域沙东南构造带处于沙垒田凸起向沙南凹陷的过渡部位,受继承性凸起、不同时期同沉积断裂和古沟谷多种因素影响,沉积相的发育较为复杂,制约了下步油气勘探。为此,通过分析由地层厚度法恢复的沙东南构造带东营组各三级层序沉积时期的古地貌,明确了研究区发育凸起区、斜坡区、古沟谷、断槽、浅洼和深洼陷区等多种地貌单元。同时,以北北东向转换断裂为界,划分出两种不同的地貌组合分区:西区为由侵蚀沟谷、古潜山斜坡和早期同沉积断裂组成的沟谷-斜坡-断坡地貌,东区为由侵蚀沟谷、2~3条同向不同期同沉积断层组成的沟谷-多级断坡地貌。研究表明两种构造地貌中位于凸起边缘的沟谷早期均为物源通道,晚期接受沉积充填,对沉积相类型、分布以及充填控制的差异主要受斜坡-断坡和多级断坡的影响:在沟谷-斜坡-断坡地貌中,沉积体系的分布和沉积充填过程主要受古斜坡-断坡控制,控制断坡的同沉积断裂在沙河街组活动较强,控制了沙河街组低位扇、浊积扇的沉积和充填,SQ-Ed3时期断裂活动逐渐减弱,继承性断坡地貌成为SQ-Ed3层序扇三角洲平原和前缘以及SQEd2d,SQ-Edu2时期辫状河三角洲前缘和滨浅湖沉积的大致界限;在沟谷-多级断坡地貌中,形成于SQ-Ed3时期的沙东南1号断裂仅在SQ-Ed3时期活动,控制了深洼陷的形成和一级坡折之下小型扇三角洲的发育,形成于SQ-Ed2d时期的沙南断裂主要活动时期也在SQ-Ed2d,形成了分隔凸起与斜坡间的二级坡折,控制了SQ-Ed2d小型扇三角洲的沉积充填。  相似文献   
84.
南海油气资源储量巨大,近年来周边国家对该海域油气资源的争夺日益白热化,南海领土及油气资源归属的矛盾日益突出,及时监测海上油气钻井平台的分布及其变化状况,对维护国家海洋权益和海洋资源环境保护具有重要意义。针对南海油气钻井平台的监测问题,从遥感影像的数据源选择和识别方法2个方面对近年来南海油气钻井平台的遥感监测情况进行了分析总结,同时聚焦目前对南海油气钻井平台的监测需求,分析了当前研究面临的问题和挑战,提出了下一步研究方向。  相似文献   
85.
《China Geology》2021,4(4):541-552
The intersection of the Kyushu-Palau Ridge (KPR) and the Central Basin Rift (CBR) of the West Philippine Basin (WPB) is a relic of a trench-trench-rift (TTR) type triple-junction, which preserves some pivotal information on the cessation of the seafloor spreading of the WPB, the emplacement and disintegration of the proto-Izu-Bonin-Mariana (IBM) Arc, and the transition from initial rifting to steady-state spreading of the Parece Vela Basin (PVB). However, the structural characteristics of this triple-junction have not been thoroughly understood. In this paper, using the newly acquired multi-beam bathymetric, gravity, and magnetic data obtained by the Qingdao Institute of Marine Geology, China Geological Survey, the authors depict the topographic, gravity, and magnetic characteristics of the triple-junction and adjacent region. Calculations including the upward continuations and total horizontal derivatives of gravity anomaly are also performed to highlight the major structural features and discontinuities. Based on these works, the morphological and structural features and their formation mechanisms are analyzed. The results show that the last episode amagmatic extension along the CBR led to the formation of a deep rift valley, which extends eastward and incised the KPR. The morphological and structural fabrics of the KPR near and to the south of the triple-junction are consistent with those of the western PVB, manifesting as a series of NNE-SSW- and N-S-trending ridges and troughs, which were produced by the extensional faults associated with the initial rifting of the PVB. The superposition of the above two reasons induced the prominent discontinuity of the KPR in deep and shallow crustal structures between 15°N–15°30′N and 13°30′N–14°N. Combined with previous authors’ results, we propose that the stress produced by the early spreading of the PVB transmitted westward and promoted the final stage amagmatic extension of the CBR. The eastward propagation of the CBR destroyed the KPR, of which the magmatism had decayed or ceased at that time. The destruction mechanism of the KPR associated with the rifting of the PVB varies along strike the KPR. Adjacent to the triple-junction, the KPR was destroyed mainly due to the oblique intersection of the PVB rifting center. Whereas south of the triple-junction, the KPR was destroyed by the E-W-directional extensional faulting on its whole width.©2021 China Geology Editorial Office.  相似文献   
86.
利用1961—2016年山西盛夏(7—8月)平均降水和同期NOAA重构海温资料,分析了山西盛夏降水分别与赤道中东太平洋海温和西太平洋暖池海温相关性的变化。结果表明:山西盛夏降水和赤道中东太平洋海温之间呈现稳定的显著负相关;和西太平洋暖池海温呈现正相关,并在20世纪70年代末到80年代初之后相关性加强,通过了0.05显著性检验。进一步分析表明,这种西太平洋暖池海温对20世纪80年代以来山西盛夏降水指示意义加强的事实,主要体现在赤道中东太平洋海温偏冷的背景下。西太平洋暖池海温异常通过影响与山西盛夏降水密切相关的大气环流、季风槽位置和东亚夏季风,导致山西盛夏降水异常。盛夏赤道中东太平洋海温偏冷时,西太平洋暖池海温偏暖(冷),通过遥相关引起中高纬度大气欧亚—太平洋型遥相关(EUP)和负太平洋—日本(PJ)波列,通过影响季风槽位置偏西偏北(偏东偏南),引起西太平洋副热带高压偏北(南)和季风指数偏小(大),导致山西盛夏降水偏多(少)。  相似文献   
87.
To carry out this research, interpolated data of daily rainfall from Iran’s Asfazari data base during 1/1/1979–31/12/2013 is used. The day along with pervasive rainfall considered a day that at least 50% of Iran’s territory has received more than 1 mm for at least two consecutive days. Based on mentioned thresholds, 224 days selected for statistical analysis. The sea level pressure data, zonal and meridional wind components and specific humidity with spatial resolution of 0.25*0.25 Gaussian degree in spatial domain of 10 °N to 60 °N and 15 °E to 75 °E obtained from the European Center for Medium range Weather Forecasting (ECMWF) ERA-Interim for selected days. Then on the data matrix of sea level pressure, the cluster analysis by Ward linkage method done and 4 sea level pressure patterns with different configuration of synoptic systems were identified. The findings showed that in the sea level, the interaction between southern thermal low pressure systems (Arabia low pressure) with Europe and Siberia cold immigrant high pressure both by individual and integration and anticyclone circulation of Arab sea from the low level of 1000–500 hPa of troposphere have the most role on occurrence of durable and pervasive rainfall of Iran. The most Vertically Integrated Moisture Flux Convergence in the first layer of troposphere (1000–850 hPa) observed in low height regions, in the second layer of troposphere (775–700 hPa) on Zagros Mountains and in third layer of troposphere (600–500 hPa) is seen in mountains leeward of Iran. Also the results showed that the maximum rainfall cores has the most coordination with Vertically Integrated Moisture Flux Convergence (VIMFC) in the second layer of troposphere (775–700 hPa) on the Zagros heights in the southwest of Iran.  相似文献   
88.
南海夏季风爆发时间在1993/1994年出现显著的年代际提早, 探讨了大气要素场的不同时间尺度分量季节演变的年代际变异对南海夏季风爆发时间的年代际变异的相对影响作用。南海夏季风爆发时间的年代际提早与南海季风区对流层经向温度梯度季节性逆转的年代际提早有密切联系。南海季风区5月中对流层经向温度梯度年代际增强主要由季风区北部温度的年代际显著增暖造成。季内分量和季节以上分量对1993年之前南海季风区经向温度梯度逆转及加强时间偏晚的作用同等重要。经向温度梯度距平的季节以上分量主要源于季风区北部温度相应分量的贡献, 而季节内分量则主要由南部相应分量影响所致, 并由25~90 d分量所主导。季节以上分量对1994年之后南海季风区经向温度梯度逆转及加强时间偏早的贡献要大于季节内分量的贡献。经向温度梯度距平的季节以上分量和季内分量对总距平的正贡献都主要来自于季风区北部温度相应分量。两种季内低频分量对温度梯度季内分量的贡献率相当, 10~25 d分量主要由南海北部温度相应分量所主导, 25~90 d分量对总距平的正贡献也源自北部分量。准双周振荡分量对各年代南海夏季风爆发具有明显的触发作用。   相似文献   
89.
南海季风爆发的年代际转折与东亚副热带夏季降水的关系   总被引:1,自引:0,他引:1  
利用1979—2016年NCEP再分析资料, 分析了南海季风爆发的年代际转折与东亚副热带夏季降水的关系。结果表明:南海夏季风爆发时间在1993/1994年出现年代际转变, 1979—1993年爆发时间相对偏晚, 夏季华南降水偏少, 长江中下游至日本南部降水偏多; 1994—2016年爆发时间偏早, 夏季华南降水偏多, 长江中下游到日本南部降水偏少。南海季风爆发时间年代际转折与夏季东亚副热带降水关系可能受到菲律宾越赤道气流强度的调控, 季风爆发时间与菲律宾越赤道气流有显著正相关, 且均在1993/1994年间存在年代际转变。在1994—2016(1979—1993)年南海夏季风爆发偏早(晚), 菲律宾越赤道气流偏弱(强), 澳大利亚北部有偏北(南)风异常, 将暖池的热量往赤道输送, 使得赤道对流增强(减弱), 产生异常上升(下沉)运动汇入Hadley环流上升支, 增强(减弱)的Hadley环流导致下沉主体偏北(南), 促使副高脊线偏北(南), 从西北太平洋(孟加拉湾)往华南地区(江淮到日本南部)输送水汽增强, 所以华南(江淮到日本南部)夏季降水偏多。   相似文献   
90.
Marine protected areas (MPAs) hold great promise as an effective conservation tool, but the potential negative socioeconomic impacts of MPAs remain poorly understood. Indeed, little work has been done to advance the frameworks and methods needed to assess, measure, and communicate the potential negative socioeconomic impact of MPAs and incorporate this information in MPA planning and management efforts. To address this gap, we test a vulnerability assessment termed the Livelihood Vulnerability Index (LVI) that is designed to measure the relative potential impact a proposed MPA network may have upon fisherman livelihoods. To test the LVI, specifically we ask, how does the vulnerability of fishermen to the impact of MPAs differ across place? We explore this question through two core areas of inquiry surrounding the study of vulnerability assessments: 1) Ranking and comparing vulnerability and 2) Explaining attributes of vulnerability. Through this study we demonstrate how the historical and current conditions fishermen experience in a given place shape vulnerability levels in various ways. Variability in the attributes of a particular place such as weather conditions, the size of fishing areas, availability of alternative fisheries, and changes in kelp cover contribute inherently as measures of vulnerability but they also shape fishermen perceptions of what are important measures of vulnerability. Secondly, counter to existing notions, the use of weights in vulnerability assessments may not significantly impact vulnerability scores and ranking. Together these findings emphasize the need to test vulnerability assessments against actual experienced impact or harm across geographies and groups of fishermen towards an informed refinement of vulnerability assessments. We emphasize that the particularities of place are critical to understand, to appropriately assess and thus to effectively mitigate vulnerability in order to promote the future well being of fisherman livelihoods.  相似文献   
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