北印度洋赤道海岭的远洋沉积记录在氧同位素第6期的早期，即167～160ka期间，揭示出一次重大的古海洋学事件.在多项代用指标中，浮游有孔虫组合和通量的变化对该事件的反映最为强烈，因此将其命名为“第6期海洋生态环境严重恶化事件”.该事件以广适性种Globigerinitaglutinata的高度发育、凉水种Neogloboquadrinapachyderma和Globigerinabulloides的异常增多、其他有孔虫常见种的普遍减少及有孔虫总量的大幅度降低为特征.结合其他代用指标和邻区资料，认为导致事件发生的主控因素在于超强的南亚冬季风及其所引发的表层水温降低和贫瘠的深层水团上涌.一般情况下，南亚冬季风对研究区环境的影响力远较夏季风弱，它的阶段性超常强化似乎总与青藏高原的强烈隆升有关.可推测，发生在第6期的生境恶化事件很可能是最近一次高原大规模构造抬升的产物.

We report petrological and geochemical data on ultramafic pillow lavas from Late Palaeozoic marine sequences in Yunnan, SW China. These lavas have >26wt% MgO, euhedral to subhedral olivine phenocrysts and acicular or quench clinopyroxene crystals with or without microlitic plagioclase in a devitrified and altered (>18wt% MgO), but we term them high-Mg picrites because they lack spinifex-textured olivine. Although olivines in these picrites are cumulate crystals, causing the high MgO contents of the bulk rocks, the high forsterite content of these olivines, Fo=0.902±0.011, suggests that the primitive magmas parental to the picrites have had >171-19% MgO, which is similar to the estimates for primary magmas of the Cretaceous Gorgona komatiites in the literature. The calculated liquidus temperature of the primitive magmas parental to the Yunnan picrites is >1400±25℃, which would imply a mantle potential temperature of >1540±30℃. This is inconsistent with magma generation beneath ocean ridges or in the mantle wedge above a subduction zone, but is consistent with a mantle plume origin, which is fully supported by the trace element characteristics of the magmas.

东经90°海岭的北部远洋型沉积记录是青藏高原隆升的远程监视器。文章应用有孔虫组合分析和壳体微量元素分析，结合相关的沉积学、地球化学、古地磁学和微体古生物学工作，对以ODP758钻孔为代表的9Ma以来的沉积记录综合研讨，识别出对应于高原阶段隆升（317～312Ma、0.8～0.6Ma、0.17～0.16Ma）的重大环境变化信号。文章还提出印度冬季季风强度是反映高原构造活动关键标志的观点。按照这种观点，海岭远洋记录提供的晚新生代最大环境转折时段位于3.7～3.2Ma间。

以新生代印度尼西亚多岛海沉积记录作为典型分析对象，对陆（岛）海相间结构背景下的沉积作用的主要特征及其构造地理意义进行讨论。各种类型的深水沉积作用在多岛海槛式盆地中多有反映，但以浊积和半远洋沉积最为突出，典型的远洋沉积仅发育于多岛海外围的开放大洋地区。连续而持久的远洋沉积记录是判别古代洋盆规模的最有效的依据之一。云南昌宁—孟连造山带作为古特提斯多岛洋主洋盆，包含的以放射虫硅质岩为代表的远洋记录覆盖的地质历史至少达130Ma。结合明显的等深流记录、可能的巨大火成区记录、巨量陆屑输入记录等多方面的证据，笔者认为，云南地区所揭示的东古特提斯的规模远非当代的印尼多岛海可比。对多岛海背景下的若干古海洋学问题也进行了讨论。

实地观测和对沉积记录的研究表明，孟加拉湾存在强大的等深流活动。通过采自孟加拉深海扇东部和中部的3支活塞岩心的沉积学研究表明，那些氧化色彩强烈、钙质生物壳体溶蚀严重、不存在粒序层理的粉砂质薄层实际上是等深积作用的产物。源自两极的等深流是全球温盐循环系统的关键组分，它们在过去150ka的历史中曾经多次得到强化，不仅对研究区的环境变化产生重要影响，而且可能作为纽带，加强了低纬地区与极区在气候意义上的遥相关。等深流的强化与冰川旋回之间似乎不存在密切关联，氧同位素第3，4，5期内均可发现明显的强化记录。关于强化的控制机制有待深入探讨。

通过相轮分析，讨论了北印度洋孟加拉深海扇扇区和东经90°海岭岭区的沉积记录部分环境指标间可能存在的相互联系。60kaBP以来短周期的快速变化在扇区得到充分反映，其中，古生产力的变化与夏季季风的兴衰并非呈简单的线性关系。与西北印度洋的替代性指标意义相反，上升流种Globigerinabulloides的相对富集在研究区不是印度夏季季风增强反是其减弱的信号。岭区记录在更长的时间范围内显示了与扇区记录基本对应的气候演化特征。还初步讨论了发生于165kaBP前后的重大海洋生态环境恶化事件，认为其很可能亦是印度季风活动的产物。

The orbital and interior climatic cycles can be found both in the Bengal Deep Sea Fan and Ninetyeast Ridge, North Indian Ocean. The periodicity of the Quaternary glacio-eustacy by 100ka gave a strong impact on the sedimentation in the fan area and the monsoon signals controlled by the obliquity and precession were easily picked up. This paper discusses the possible correlation between the environmental elements on the basis of the ETP phase wheels. A rapid change with short-periods develops during the past 60 ka in the region under study as well. The variability of paleoproductivity has a nonlinear response to the Indian summer monsoon. As contrasted to the Northwest Indian Ocean, here an abundance of Globigerina bulloides, a proxy to indicate upwelling current, does not imply so much a promotion of the summer monsoon as its decrease. The record from the ridge area shows in a longer-scale a climatic evolutionary feature corresponding to that of the fan area. A special and great event arising at around 165 kaBP and meaning a catastrophe for ecological environment is reported in this paper. It is also regarded as a result induced by the monsoon.

本文在综合东北印度洋域5支深海钻芯和7支活塞柱状芯资料的基础上，对该区沉积作用及其形成的记录与北部山脉和高原隆升的关系进行讨论。过去有关深海记录对造山带构造活动响应的研究多集中于孟加拉浊积扇，而90°E海岭的远洋沉积记录通过海气相互作用系统作为中介，可能包含响应隆升的重大环境信号。初步研究表明，远洋记录中的碳酸盐含量、有孔虫的形态结构和若干微量元素特征的剧变期与已知的高原构造阶段存在密切的对应关系，其中，距今8Ma、3.7Ma、0.8Ma和0.16Ma所反映的变化尤为突出。

北印度洋孟加拉扇远源区的半远洋沉积记录在氧同位素第2期早期及第3期包含大量高频气候波动信号。该区MD77190柱状样自第3期起由以富钙质生物壳体和贫钙质生物壳体为主要特色的两类沉积物构成韵律互层，它们的分布状态、互换频率及在生物和化学组分方面的细微变化反映出59000～21000aB.P。期间研究区可与Heinrich和DamgaaId/Oeschger事件遥相对比的气候演化特征。有关的全球热传输机制有待深入探讨。

As a trunk part of the Paleo-Tethyan archipelago ocean, the Changning-Menglian belt of western Yunnan, China, presents varied volcano-sedimentary records ranging in time from Early Devonian through Middle-Late Triassic. The typical pelagic sediments represented by radiolarites can not only signify a continuously evolved ocean but also constitute a complicated basin comprising different tectono-sedimentary units. It is likely that oceanic plateaus of diverse origins played a key role in constructing the pattern of eastern Tethys. The opening and closing of the Yunnan Tethys are discussed in the paper as well. 0 AcadCmie des sciences 1 Elsevier. Paris.