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1.
Late Paleozoic strata in northeastern China are distributed in a zonal pattern around the old-land on the Jiamusi-Mongolia Block.They are composed of active deposits in the regular distributed tectonic lithofacies zones.This indicates that the late Paleozoic strata belong to continental margin deposits.According to the strong conformability of the sedimentary strata in the same continental margin and distinct differences among the three continental margins,three stratigraphical regions of the Jiamusi-Mongolia Stratigraphical Province are recognized along the northern,southern and eastern margins of the Jiamusi-Mongolia Block,named respectively as Xing’an Stratigraphical Region,Inner Mongolia grass--Songhua River Stratigraphical Region and Baoqing--Hunchun Stratigraphical Region.Due to the characteristics of continental margin deposits and active sediments,the strata can be correlated on the level of formation by the methods of analysing the rock association in the same stratigraphic region.Therefore,some revisions of the lithological formations of the late Paleozoic strata in northeastern China have been made,and a new chart of lithostratigraphic correlation has been proposed.Furthermore,the present stratigraphic framework is setting on the International Stratigraphic Chart on the level of stage,after comprehensive researches to lithostratigraphy,biostratigraphy and chronostratigraphy,especially the conodont biostratigraphy and isotopic ages of volcanic rocks obtained in recent years. 相似文献
2.
Based on 48-year (1958-2006) ocean reanalysis data of Simple Ocean Data Assimilation and 23-year (1984-2006) global ocean-surface heat flux products developed by the Objectively Analyzed Air-Sea Heat Flux Project, meridional variation of the western Pacific Warm Pool (WPWP) is addressed. The results show that there is a significant expansion of the northern edge of the WPWP in the late 1990s and early 2000s. This variation is mainly within 120°E-160°E by 8°N-20°N, we define this region (120°E-160°E by 8°N-20°N) as the core region. Furthermore, analyses on upper ocean heat budget show that the short wave radiation plays a key role in the northward expansion of the northern edge of the WPWP in the core region. It is proved that the northward expansion may be caused by the change of the mixed layer which became shallower in 1994-2006 compared with 1984-1993 in the study region. The short wave radiation flux distribution within the shallower mixed layer leads to a positive anomaly in seawater temperature, promoting the northward expansion of the WPWP. 相似文献
3.
1 Introduction From July 10th to September 26, 2003,“Xuelong”scientific expedition icebreaker executed the 2nd Chinese Arctic Research Expedition (CHINARE2003). The voyage star- ted from Shanghai to Dalian via Yellow Sea and Bo Hai and the cruising rout… 相似文献
4.
Estimates of near surface layer parameters over 78°N drifting ice in ice camp over the Arctic ocean are made using bulk transfer methods with the data from the experiments operated by the Chinese Arctic Scientific Expedition in August 22-September 3,2003.The results show that the net radiation received by the snow surface is only 3.6 W/m2,among which the main part transported into atmosphere in term of sensible heat and latent heat,which account for 52% and 31% respectively,and less part being transported to deep ice in the conductive process.The bulk transfer coefficient of momentum is about 1.16×10-3 in the near neutral layer,which is a little smaller than that obtained over 75°N drifting ice.However,to compare with the results observed over 75°N drifting ice over the Arctic Ocean in 1999,it can be found that the thermodynamic and momentum of interactions between sea and air are significant different with latitudes,concentration and the scale of sea ice.It is very important on considering the effect of sea-air-ice interaction over the Arctic Ocean when studying climate modeling. 相似文献
5.
青藏高原东南缘位于印度板块与欧亚板块侧向汇聚部位,是检验碰撞造山动力学模型的理想场所。尽可能全面收集该区已有地球物理和新生代岩浆岩数据,探讨这些资料对碰撞造山带结构和物质组成的指示。结果表明:青藏高原东南缘不同部位的壳幔结构和组成存在较大差异。兰坪—思茅地块、保山地块和腾冲地块等的中地壳(15~30 km深度)普遍发育低速层,表明富水层或者部分熔融物质的存在,为青藏高原物质向东南流动提供了可能。部分熔融产物以大型剪切带内具有高Sr、低Nd同位素特征的淡色花岗岩脉为代表。但是,扬子板块同等深度下却发育高速层,其组成很可能是峨眉山玄武岩,它的存在阻隔了碰撞带物质向东流动。扬子板块和兰坪—思茅地块下地壳底部均出现呈条带状展布的高速体。根据新生代具有高Sr、低Y的岩石显示的下地壳源区特征,结合该区地质演化历史,将上述两套呈条带状展布的高速体分别解释为新元古代铁镁质弧岩浆岩和二叠纪—三叠纪铁镁质弧岩浆岩。青藏高原东南缘地幔各向异性存在明显南、北分区特征,在26°N以北表现为SN向,在26°N以南表现为近EW向。这一差异跟俯冲的印度板片撕裂有密切关系。该撕裂在综合地球物理剖面上显示为突变的印度板片俯冲角度,在地表表现为苦橄岩、煌斑岩、埃达克岩以及淡色花岗岩等的集中出露。这一新模型明显区别于前人的岩石圈拆沉和对流减薄等作用。 相似文献
6.
Yang Zongrang 《地球科学与环境学报》1997,(1)
在分析了近年来秦、祁、昆造山带研究中部分成果资料的基础上，认为商、丹主缝合线以南的杨子古陆北缘区早古生代由于一系列“三叉”裂谷系的发育而曾沿布尔汉布达山─略阳─山阳─线打开一次洋盆，致使南秦岭─柴达木－带从扬子陆块北缘分离出来，一度成为一独立微古陆块向北漂移；古生代有其独特的演化历史。而当时主洋盆北侧的华北古陆南缘区则发育有完整的沟、弧、盆体系．面貌很象今天的太平洋西海岸。 相似文献
7.
现今绝对板块运动 总被引：1，自引：0，他引：1
魏子卿 《地球科学与环境学报》2009,31(4):331-343
根据热点假设,热点对于中间层是固定的.相对热点的板块运动叫做绝对板块运动.绝对板块运动模型可以通过反演火山链传播的速率和走向数据以确定相对板块运动在角速度空间的原点来得到.利用一组近来(0～7.8 Ma)全球分布的热点的迁移速率和走向数据,结合板块运动模型NNR-NUVEL1A,已研制出一个叫做APM2的现今绝对板块运动模型.按照该模型,太平洋板块围绕60.063°S、102.210°E处的极以(0.833 0°±0.013 3°)/Ma的速率运动,非洲板块围绕46.849°N、44.372°W的极以(0.101 5°±0.013 4°)/Ma的速率运动,南极板块的运动则以46.871°N、146.942°E为极,速率为(0.084 6°±0.017 7°)/Ma,欧亚板块的运动更慢,极为27.291°N、171.925°W,速率为(0.065 5°±0.020 6°)/Ma.这一模型表明,岩石圈相对深部地幔有一个以49.423°S、90.625°E为极,速率为(0.198 3°±0.013 5°)/Ma的净旋转.表明太平洋热点同印度-大西洋热点不一致,显示太平洋热点的运动也不一致.为了分析和比较,还给出了仅用全球分布的热点的走向数据和仅用印度-大西洋热点的走向数据得到的板块绝对运动的角速度. 相似文献
8.
The relationships between the neon flying squid, Ommastrephes bartrami, and the relative ocean environmental factors are analyzed. The environmental factors collected are sea surface temperature (SST), chlorophyll concentration (Chl-a) and sea surface height (SSH) from NASA, as well as the yields of neon flying squid in the North Pacific Ocean. The results show that the favorable temperature for neon flying squid living is 10℃-22℃ and the favorite temperature is between 15℃-17℃. The Chl-a concentration is 0.1-0.6 mg/m3. When Chl-a concentration changes to 0.12-0.14 mg/m3, the probability of forming fishing ground becomes very high. In most fishing grounds,the SSH is higher than the mean SSH. The generalized additive model (GAM) was applied to analyze the correlations between neon flying squid and ocean environmental factors. Every year, squids migrate northward from June to August and return southward during October-November, and the characteristics of the both migrations are very different. When squids migrate to the north, most relationships between the yields and SST are positive. The relationships are negative when squids move to southward. The relationships between the yields and Chl-a concentrations are negative from June to October, and insignificant in November. There is no obvious correlation between the catches of squid and longitude, but good with latitude. 相似文献
9.
利用海南及邻区1999年以来GNSS资料及1970年以来水准数据获取三维运动速度场，分析地壳运动特征，结合东南亚水平运动背景场分析周缘板块对海南地块及华南地块陆缘速度场的影响。结果表明，海南岛三维运动以白沙断裂为界，岛北部以海口-屯昌为界。华南地块各观测点E向运动速率自西向东逐渐减小，至陆缘区域速率最小，各观测站间运动速率差异性小；S向运动速率自西向东逐渐增大；位于23°～26°N区域观测点的速度场与其南北两侧存在差异。华南地块运动受印度板块与欧亚板块碰撞和挤压影响，陆缘地带还受太平洋板块、菲律宾海板块活动及南海扩张运动影响，澳大利亚板块对区域运动影响较小。 相似文献
10.
黔南祥摆组的化石资料稀少且以植物化石为主,在独山县羊凤乡祥摆组中发现了一个海相动物群,主要化石有腕足类、珊瑚类、苔藓虫类、头足类和遗迹化石,其中以腕足类最为丰富.在鉴定分析所发现化石的基础上,结合该动物群所在层位的岩性特征、矿物特征和区域上该时期的沉积特征,采用古生态学分析方法,认为该动物群生存环境为一个淡化潟湖.区域上,该潟湖主要位于平塘县与独山县之间,而构成潟湖与外海的障壁则主要位于摆者至麻尾一线东北,呈北西向延伸;在北部兔场附近祥摆组已演变为以泛滥平原沉积为主.潟湖范围内现今构造形态完整,同时这种局限低能的沉积环境可以形成良好的烃源岩,因此它们在区域上的分布对岩相古地理和油气生储盖组合研究具有重要意义. 相似文献
11.
Monthly ocean temperature from ORAS4 datasets and atmospheric data from NCEP/NCAR Reanalysis I/II were used to analyze the relationship between the intensity of the South Asian summer monsoon(SASM) and upper ocean heat content(HC) in the tropical Indo-Pacific Ocean.The monsoon was differentiated into a Southwest Asian Summer Monsoon(SWASM)(2.5°–20°N,35°–70°E) and Southeast Asian Summer Monsoon(SEASM)(2.5°–20°N,70°–110°E).Results show that before the 1976/77 climate shift,the SWASM was strongly related to HC in the southern Indian Ocean and tropical Pacific Ocean.The southern Indian Ocean affected SWASM by altering the pressure gradient between southern Africa and the northern Indian Ocean and by enhancing the Somali cross-equatorial flow.The tropical Pacific impacted the SWASM through the remote forcing of ENSO.After the 1976/77 shift,there was a close relationship between equatorial central Pacific HC and the SEASM.However,before that shift,their relationship was weak. 相似文献
12.
四川"9.3"大暴雨中的水汽输送分析 总被引：4，自引：0，他引：4
利用NCEP／NCAR再分析资料对四川“9．3”大暴雨中水汽来源进行了讨论。结果表明,这次暴雨的水汽主要来源于南海、西太平洋地区;异常水汽输送在这次暴雨中占了较大的比例。暴雨日及前3天的异常水汽输送表明,造成此次川东暴雨的异常水汽来源于西太平洋经南海、东海、黄海的向北水汽输送和暴雨区北方的向南水汽输送,以及青藏高原的异常偏西风输送,孟加拉湾的水汽输送对异常强降水并没有明显的作用。大暴雨发生的前期,副高突然异常加强西伸。 相似文献
13.
Atmospheric nitrous oxide observations above the oceanic surface during the first Chinese Arctic Research Expedition 总被引：1，自引：0，他引：1
339 gas samples above oceanic surface were collected on the cruise of "Xuelong" expeditionary ship and nitrous oxide concentrations were analyzed in the laboratory. Results showed that Atmospheric average N2O concentration was 309 ±3. 8nL/L above the surface of northern Pacific and Arctic ocean. N2O concentrations were significantly different on the northbound and southbound track in the range of the same latitude, 308.0 ±3.5 nL/L from Shanghai harbor to the Arctic and 311.9 ±2.5 nL/L from the Arctic to Shanghai harbor. N2O concentration had a greater changing magnitude on the mid- and high-latitude oceanic surface of northern Pacific Ocean than in the other latitudinal ranges. The correlation between the concentrations of the compositions in the aerosol samples and atmospheric N2 O showed that continental sources had a great contribution on atmospheric N2 O concentration above the oceanic surface. Atmospheric N2O concentration significantly increased when the expeditionary ship approached Shanghai h 相似文献
14.
周静 《广东海洋大学学报》2009,29(5):31-33
2009年7月20日至21日,由广东社会学学会海洋专业委员会发起,广东海洋大学和中国海洋大学联合主办了"中国海洋社会变迁与海洋社会学学科建设学术研讨会"。会议围绕海洋社会学学科建设与深入海洋社会研究的两大主题展开交流与讨论,展现我国社会学学者的海洋关怀与主张,展望了基于田野灵感的经验分析和理论建构的海洋社会学学科研究的操作途径和发展前景。 相似文献
15.
方曙 《大地测量与地球动力学》2021,41(6):551-560
洋中脊是大洋的胚胎,从洋中脊为地堑式中央裂谷的形态特征来看,大洋是拉张应力的产物,因此必须依据大陆漂移造成海底被动扩张这一结论来分析研究板块运动的动力源问题。大陆漂移的方向是有规律的,根据世界大洋年龄图等资料进行逆推,还原不同阶段的洋陆展布状态,可以看出,白垩纪以来南半球大陆分解向北运动、北半球大陆分解向南运动,大陆在向低纬度地区运动的过程中向西运动,这种大陆漂移的方向性特征与地球自转力作用的方向性特征完全吻合。根据模拟实验,在空心不锈钢球体的中高纬度表面吸附具有一定质量的磁扣并旋转不锈钢球体,当达到一定转速时,磁扣会向赤道漂移,同时向西漂移。同理,地球上的大陆高出大洋,当中高纬度的大陆自转离极力大于前方大洋阻力时,必然会造成大陆在大洋之上仰冲,也就是大陆在大洋之上漂移。根据离极力理论计算可知,中心在中纬度的大陆产生的离极力足以使前方大洋破裂屈服,从而发生指向赤道方向的逆冲运动;而向赤道运动的大陆因旋转半径变大会产生强烈的向西的同步力,造成大陆西侧大洋破裂并发生逆冲运动,从而向西漂移。板块运动的本质就是大陆挤压大洋造成洋壳破裂逆冲,陆壳于洋壳之上作仰冲运动,大陆前方的古大洋逐渐被俯冲消亡,最终与前方大陆碰撞造山合并成新的大陆;而由于大陆的前行造成其后的岩石圈普遍处于张裂状态,导致原大陆被拉张分解为2个或多个陆块,分裂的陆块之间沿洋中脊增长生长为新大洋。地球自转形成的地转力除造成板块运动外,还可能使岩石圈内部发生断裂,并在已有断裂上积累和释放势能,从而造成地震。 相似文献
16.
近30年西北太平洋热带气旋时空特征分析 总被引：1，自引：0，他引：1
本文利用近30年热带气旋年鉴建立了西北太平洋热带气旋灾害数据库,以.NET和ArcGIS Engine搭建了二次开发平台(其包括登录界面、图查属性、 属性查图、数据库分析处理等功能),分析了西北太平洋热带气旋的时间特征、空间特征,以及时空变化特征。结果表明,30年来西北太平洋共生成905次热带气旋,年均30.2次/年。其中,7-10月最容易发生热带气旋,占所有热带气旋的35.7%,8月份达到峰值,达21.5%,2月最不容易发生热带气旋,发生频率仅为0.6%,而8-10月是强台风和超强台风发生的月份。热带气旋源地集中区位于(10°~22°N,112°~120°E)、(8°~20°N,126°~134°E)和(6°~20°N,136°~150°E),具有纬度带和经度带的分布特性。源地的空间分布存在明显的季节变化和月变化特征,在季节尺度上,夏季主要集中在偏北偏西位置,并向南向东偏移,冬季向北向西偏移;在月尺度上,1-4月源地相对分散;5-6月相对于1-4月的源地位置发生向西向北方向转移;7月向东向北扩散,8-9月向西扩散,9月源地相对集中,10月热带气旋源地南移, 11-12月热带气旋源地范围明显减小。 相似文献
17.
前期印度洋海温异常对中国春季降水的影响 总被引：2，自引：0，他引：2
为了进一步认识印度洋海温的异常变化与中国降水的关系,采用SVD分析、相关分析及合成差值分析讨论了前期冬季关键区海温的异常变化对中国春季降水影响的差异,探讨了产生这种影响的原因。结果表明:前期冬季关键区海温的异常增高(降低),会造成后期春季中国华北往南到华中、华东、华南东部及西北的新疆地区的降水明显增多(减少),西南的四川、贵州及华南的广西等地降水会有所减少(增多)。与关键区冷年相比,在关键区的暖年,环流形势反映出东欧槽显著减弱,北方气压显著降低,蒙古高压明显减弱,冷空气南下更为明显,而华南东部、华中、华东及华北一直被较为显著的南风气流控制,海洋的暖湿气流向中国内陆输送更为显著,使得东部及中部大部分地区水汽较为充沛,形成大面积的降水。 相似文献
18.
塔什库尔干县马尔洋乡大河口一带发育灰绿色斜长角闪岩,全岩地球化学分析结果显示其属于钙碱性系列,原岩为基性火山岩,形成于会聚阶段的板块边缘。锆石LA-ICP-MS U-Pb年龄为512±3.8 Ma,揭示其形成时代为早古生代,与区域上康西瓦构造结合带的形成同期。据此推断,大河口斜长角闪岩的形成与古特提斯洋演化密切相关,是原特提斯洋俯冲消减的产物。 相似文献
19.
中亚造山带是世界上最大的显生宙增生型造山带,是研究增生造山过程和大陆地壳生长的绝佳场所,其形成记录了新元古代—早中生代古亚洲洋发展演化历程,主要由一系列微陆块、岛弧、海山/大洋高原、增生杂岩及蛇绿混杂岩构成。中亚造山带西段蛇绿混杂岩物质组成基本一致,除了典型的蛇绿岩组分外,大多发育典型的海山岩石组合,即枕状玄武岩、火山角砾岩、礁灰岩、滑塌堆积岩、陆源碎屑岩。蛇绿混杂岩中基性岩在地球化学上可明显分为两类:一类为洋中脊玄武岩型,属于拉斑系列,显示俯冲带特征;另一类为洋岛玄武岩型,属于碱性玄武岩系列,形成于海山/大洋高原环境。中亚造山带西段蛇绿混杂岩和变质岩的时代、属性及空间分布,表明古亚洲洋俯冲起始时限不晚于新元古代早期,位置应在西伯利亚南缘,并逐渐向南发展。在古亚洲洋发育早期,地幔柱诱发俯冲起始占主导地位,后期可能由于海山/大洋高原阻塞俯冲通道,导致俯冲极性翻转和跃迁,从而发生俯冲起始。实际上,新俯冲带如何起始一直是地球科学领域的难点问题,主要原因是俯冲起始是一个极其短暂的过程,缺少直接的地质记录,并且现今地球上鲜有正在发生的俯冲起始案例。因此,需要地质学家共同努力去揭秘古亚洲洋的前世今生,破解板块俯冲起始的奥秘。 相似文献
20.
Through a sampling analysis of trace elements and ＲEE in the section of Middle Permian Zhesi For- mation in Solon area of Inner Mongolia,it is found that the overall sandstone and mudstone samples are charac- terized by LＲEE-enrichment． By analysis of the discriminant index of the sedimentary environment,the tectonic setting of Zhesi Formation is determined to be a continental island arc environment． Meanwhile,according to the sedimentary structure and lithology combination,Zhesi Formation is divided into the neritic-bathyal reten- tion-reduction environment as well as the delta front and prodelta sedimentary systems． 相似文献