苏联别林斯高晋站

1820年2月28日,两艘俄国考察船“东方”号和“和平”号在海军大尉别林斯高晋的率领下,前往南极探险。这两艘俄国帆船绕南极大陆航行一周,曾九次靠近南极海岸,取得了三百多年来许多国家航海家没有取得的结果——南极大陆总的轮廓。在南极早期发现史上具有重大意义,为纪念这位俄国航海探险家的功绩,苏联设在乔治岛的科学考察站被命名为别林斯高晋站。     

南海北部地球物理特征及地壳结构

为了研究南海地壳结构，中国和日本合作在南海北部首次进行了以炸药为震源的综合地球物理调查。经初步分析其地壳结构主要特征为：南海北部地壳分为沉积层、上地壳层、中地壳层及下地壳层。大陆架及上陆坡地壳厚度大、稳定。下陆坡地壳厚度除中地壳外，其他壳层厚度减薄且不稳定。深海盆地壳分３层，厚度虽薄但相对稳定，其底部缺失７．３ｋｍ·ｓ－１的高速层。测区内地壳总厚度：陆壳２６—３０ｋｍ，过渡壳１３—２２ｋｍ，洋壳为８ｋｍ。     

南海西北部与红河地区地球物理场及其地壳深部结构特征

分析了南海西北部与红河地区地球物理场特征，计算了研究区重、磁资料的一阶小波细节变换、四阶小波逼近变换。根据重力场资料以及南海北部盆地钻井取样的测试结果，同时参考在研究区进行的地震勘探结果，对研究区的地壳结构进行了反演计算。结果表明，研究区域地壳结构较为复杂，地壳厚度在17—38km之间，总的趋势由陆向洋地壳厚度逐渐减薄，反映出该区域地壳具有陆壳、过渡壳的性质，同时存在上地幔隆起区及凹陷区。用地震层折成像结果与重力资料计算出的地壳分布趋势进行了对比验证。根据地幔对流结果探讨了研究区深部地球动力学特征及其与深部地壳结构的关系。     

南海北部地球物理特征及地壳结构

为了研究南海地壳结构，中国和日本合作在南海北部首次进行了以炸药为震源的综合地球物理调查。经初步分析其地壳结构主要特征为：南海北部地壳分为沉积层、上地壳层、中地壳层及下地壳层。大陆架及上陆坡地壳厚度大、稳定。下陆坡地壳厚度除中地壳外，其他壳层厚度减薄且不稳定。深海盆地壳分３层，厚度虽薄但相对稳定，其底部缺失７．３ｋｍ·ｓ＾－１的高速层。测区内地壳总厚度：陆壳２６－３０ｋｍ，过渡壳１３－２２ｋｍ，洋壳     

东海的地壳结构特征

介绍了国内外有关东海地壳结构特征的调查研究状况,并利用前人大量的调查研究成果,根据自西向东地壳速度结构的差异,将东海海区划分为东海陆架区、冲绳海槽区、琉球岛弧-海沟区三部分。东海陆架区主要由沉积盖层(速度为5.8～5.9km/s)、基底层(速度为6.0～6.3km/s)和下地壳层(速度为6.8～7.6km/s)三个速度层组成,属于典型的大陆型地壳。冲绳海槽则位于大陆地壳和大洋地壳的过渡地带,它仍然具有大陆地壳的结构特征,并无洋壳的形成,但在海槽的轴部地壳已经减薄。琉球岛弧-海沟区的地壳结构总的来说属于过渡型地壳,但在海沟靠洋一侧已属于大洋型地壳,而从琉球海沟往东的西北菲律宾海盆,就完全属于典型的大洋地壳。     

南极海冰

本文利用1975—1982年南极海冰资料,分析了南极海冰的一般特征及其与南极气候的关系,南极海冰对低层气温的反馈作用和对低压中心路径的影响。     

南极极地锋季节变化特征研究

WOA13是一种平均格点化数据,它覆盖范围广,时间序列长,对于研究海洋锋的分布范围、季节变化、锋面结构有着很好的效果。利用WOA13季节平均温度数据,选取0.25经纬度网格数据,对南极洲极地锋进行了季节变化特征研究。以绝对梯度的最大值连线画出锋线具体位置,对比不同季节断面T-D分布图的差异,得到了南极极地锋的锋面结构、强度等季节变化信息。南极极地锋的锋面变化随着南极冷水的季节变化而不断伸缩,最大锋面强度位置也因此而改变,具有明显的季节变化特征。     

南极布兰斯菲尔德海域地球物理场与地质构造

本文通过对１９９１年“海洋四号”船在南极布兰斯菲尔德海域所采集的地球物理资料的分析解释，指出：区内重磁异常反映为北东向条带状展布，从北向南呈高－低－高带相间，第一带内皮状起伏，地震反射层展布及厚薄变化上应类似特征。由此揭示出区内地质构造２特征及隆坳展布格局。对布兰斯菲尔德盆地发展演变与断裂、岩浆活动、地壳拉伸、地壳深部物质变动及板块构造运动等因素的关系作了尝试性的探讨。     

在南极艾理斯峡湾和伯顿湖采集沉积物岩芯

应澳大利亚南极局的邀请和受我国国家南极考察委员会的派遣,我参加了澳大利亚南极戴维斯站1985年的越冬考察工作。 戴维斯站建于1957年,位于南极东南部的Vestfold山丘海岸边。Vestfold山丘是18000年前由于地壳的隆起,而使覆盖在上层的冰块移去,因而显露出来。在此山丘中分布着无数     

ODP199航次——古赤道断面的研究

古赤道断面 (ODP1 99航次 )将用来研究地球从新生代最暖期到南极冰川作用初期赤道太平洋洋流和风系的演变。本钻探计划的主要目的是沿 56～ 57Ma地壳的断面 ,最大程度地获取晚古新世最大热事件的富碳酸盐沉积物。其中一个站位还将钻遇 40 Ma的地壳 ,以便获取一个从中始新世到晚始新世过渡到南极冰川环境的近赤道沉积序列。如果使用的判断古位置的板块构造模型正确的话 ,PAT- 8C站位应是40 Ma时的赤道位置。由于太平洋板块随时间不断向北漂移 ,远离高生产力的赤道地区 ,早第三纪沉积物被一薄层晚第三纪的红粘土所覆盖 ,钻遇的最年轻的生…     

THE BOUGUER ANOMALIES AND DEPTHS OF MOHOROVICIC DISCONTINUITY IN THE SOUTH CHINA SEA REGION

The South China Sea is situated at the continsntal margin of South China. In this region, there are both continental and oceanic crusts. The values of Bouguer gravity anomalies on the continental shelf are low positive or low negative. Because the depth of the Mohorovicic discontinuity in this region is about 26-32 km below sea level, the crust belongs to the continental type. The values of Bouguer gravity anomalies in the deep-sea region are more than 250 mgal and the depth of the Moho-surface is about 10-15 km below sea level, so the crust is of oceanic type. The values of gravity anomalies and depths of the Moho-surface, obtained over the continental (and island) slope, range between those regions mentioned above, so the crust belongs to the transitional type. The continental crust is inferred to be directly in contact with the oceanic crust as a result of a lithospheric fault.     

从南海与大洋磁异常的相关性探讨南海的成因

对南海与大洋盆地条带状磁异常的相关分析表明，相关系数为０．１１—０．６５９，存在弱线性关系。这从一个侧面反映出边缘海洋壳与大洋壳本质上的差异。边缘海洋壳是玄武岩浆侵入并吞蚀破碎的大陆边缘地壳后形成的不同于大洋壳的新型洋壳。南海盆地磁异常显示其洋壳是新老不一、厚薄不匀的新洋壳的拼合叠覆体。     

西南印度洋中脊玄武岩地球化学特征及其对岩浆过程的指示意义

对采自西南印度洋中脊(SWIR)50°E附近5个站位的玄武岩样品进行了岩石学和元素地球化学研究.样品主量元素、TAS分类图解和AFM图解显示,SWIR研究区样品类型主要为低钾拉斑玄武岩.相对原始地幔SWIR区玄武岩具有Ba、Nb、Sr负异常,K表现为正异常.稀土元素分配模式均为左倾型,具有轻微的Eu、Ce正异常;SWI...     

西南印度洋中脊热液产物稀土元素组成变化及其来源

对西南印度洋中脊热液区不同热液产物稀土元素(REE)进行了分析,探讨了热液产物形成过程中稀土元素组成变化及其来源。研究结果表明:不同热液产物稀土元素总量变化范围从3.47×10-7到4.80×10-5,轻重稀土比值(LREE/HREE)从2.06到6.16,表明轻重稀土有较大程度分异,δEu异常(δEu=0.86~3.88)和δCe异常(δCe=0.40~0.86)显示热液产物中REE呈Eu富集和Ce亏损特征。稀土元素球粒陨石标准化模式呈现两种类型:(1)呈轻微富集LREE的平坦模式,REE大于2×10-5;(2)呈显著富集LREE和正Eu异常模式,REE小于5×10-7。模式1类似于洋壳火山岩REE配分模式,而模式2与西南印度洋中脊黑烟囱REE模式相似,也与典型洋中脊热液喷口流体和硫化物LREE富集和正Eu异常模式类似。热液产物中稀土元素含量变化和模式特征以及Mg与LREE极强正相关关系可能反映了西南印度洋中脊硫化物形成在热液流体与海水混合沉淀的初始阶段,后期经历了广泛的热液流体再循环和海水蚀变过程。     

南海北部及邻区岩石圈地幔特征与深部作用过程初探

对新生代火山活动携带到地表的超镁铁岩捕虏体岩石的主元素、微量元素和同位素特征的研究表明，南海北部及邻区岩石圈地幔组成和空间变化与大地构造分区有密切联系；区域上的岩石圈地幔经历过多重地幔交代作用，而与南海北部陆缘活化和陆缘扩张更为密切相关的地幔交代作用可能主要为高温型富Ｆｅ－Ｔｉ交代作用；软流圈热物质上升是引起大陆地壳活化的重要的深部作用因素。     

Oblique rifting in the Havre Trough and its propagation into the continental margin of New Zealand: Comparison with analogue experiments

The Havre Trough is opening by oblique back-arc rifting which is propagating into the continental margin of New Zealand at the Taupo Volcanic Zone. Variations of deformational style along the rift axis have been investigated by comparison with analogue experiments which incorporate brittle and ductile rheologies and are scaled for gravity. Based on the results of the analogue experiments, we present a tectonic model for oblique rifting in the Havre Trough, which involves the rheological contrast between oceanic and continental lithosphere and the oblique geometry of the continental margin of New Zealand with respect to the regional rift trend. The model shows that the continental margin, which is weaker than both oceanic and continental lithosphere, cannot support large shear stresses. The two lithospheres can be decoupled during extensional events along the marginal shear and, depending on the continental margin orientation, this shear can modify the regional stress field. A heterogeneous stress field will rotate normal stresses to be perpendicular or parallel to the margin. As the two lithospheres decouple during extension, the rift grabens and internal faults of the oblique rift system propagate normal to the marginal shear. This model explains the oblique trend of the Havre Trough's tectonic fabric and its relationships to the Vening Meinesz Fracture Zone which represents the oceanic/continental lithospheric boundary.As the Havre Trough rift propagates into the continental margin, rheological differences between oceanic and continental lithosphere result in variations in distribution of strain along the rift axis. Extension of oceanic sub-arc lithosphere is localized into a single rift graben. At the transition into continental rifting, the zone of extension widens into a number of rift grabens forming complex indentations into the margin. This change in deformation style is consistent with analogue experiments as well as other natural examples and results from the contrast in lithospheric rheology and its influence on the process of strain localization.     

Rare earth element geochemistry of hydrothermal deposits from Southwest Indian Ridge

The REE compositions of hydrothermal deposits and basalt samples from the Southwest Indian Ridge (SWIR) were determined with ICP-MS.The results show that there are significant differences between different types of samples although all samples show relative LREE enrichment.The contents of REE in hydrothermal sulfides and alterated rocks samples are lower (from 7.036 × 10 6 to 23.660 × 10 6),while those in the white chimney deposits are relatively higher (ranging from 84.496 × 10 6 to 103.511 × 10 6).Both of them are lower than basalts.Chondrite-normalized REE distribution patterns show that sulfides and alterated rocks samples are characterized by significant positive Eu anomalies.On the contrary,white chimney deposits have obvious negative Eu anomalies,which may be caused by abundant calcite existing in the white chimney samples.Both the content and distribution pattern of REE in sulfides suggest that REE most possibly is originally derived from hydrothermal fluids,but influenced by the submarine reducing ore-forming environment,seawater convection,mineral compositions as well as the constraint of mineral crystallizations.     

琼东南盆地陵南低凸起深水钻井岩心的稀土元素地球化学特征及其意义

A geochemical analysis of rare-earth elements(REEs) in 97 samples collected from the core of deep-water Well LS-A located at the Lingnan Low Uplift Area of the Qiongdongnan Basin is conducted, with the purpose of revealing the changes of sedimentary source and environment in the study region since Oligocene and evaluating the response of geochemical characteristics of REEs to the tectonic evolution. In the core samples, both ∑REE and ∑LREE(LREE is short for light-group REEs) fluctuate in a relatively wide range, while ∑HREE(HREE is short for heavy-group REEs) maintains a relatively stable level. With the stratigraphic chronology becoming newer, both ∑REE and ∑LREE show a gradually rising trend overall. The ∑REE of the core is relatively high from the bottom of Yacheng Formation(at a well depth of 4 207 m) to the top of Ledong Formation, and the REEs show partitioning characteristics of the enrichment of LREE, the stable content of HREE, and the negative anomaly of Eu to varying degrees. Overall the geochemical characteristics of REEs are relatively approximate to those of China's neritic sediments and loess, with significant "continental orientation". The ∑REE of the core is relatively low in the lower part of Yacheng Formation(at a well depth of 4 207–4 330 m), as shown by the REEs partitioning characteristics of the depletion of LREE, the relative enrichment of HREE, and the positive anomaly of Eu; the geochemical characteristics of REEs are approximate to those of oceanic crust and basalt overall, indicating that the provenance is primarily composed of volcanic eruption matters. As shown by the analyses based on sequence stratigraphy and mineralogy, the provenance in study region in the early Oligocene mainly resulted from the volcanic materials of the peripheral uplift areas; the continental margin materials from the north contributed only insignificantly; the provenance developed to a certain extent in the late Oligocene. Since the Miocene, the provenance has ceaselessly expanded from proximal to distal realm, embodying a characteristic of multi-source sedimentation. In the core strata with 31.5, 28.4, 25.5, 23, and 16 Ma from today, the geochemical parameters of REEs and Th/Sc ratio have significant saltation, embodying the tectonic movement events in the evolution of the Qiongdongnan Basin. In the tectonic evolution history of the South China Sea, the South China Sea Movement(34–25 Ma BP, early expansion of the South China Sea), Baiyun Movement(23 Ma BP), late expansion movement(23.5–16.5 Ma BP), expansion-settlement transition, and other important events are all clearly recorded by the geochemical characteristics of REEs in the core.