Sources and hydrothermal alteration of organic matter in Quaternary sediments: A synthesis of studies from the Central Gulf of California

Deep sea drilling in the Central Gulf of California, a young and active spreading centre, shows that the high heat flow typical of these regions causes extensive alteration of sediment organic matter, especially near sills and above magma chambers where hydrothermal activity is concentrated. Even on the nearby passive margin, where there are no sills, heat flow is moderately high and hydrocarbon generation has begun in immature sequences. Migrating light hydrocarbons are detected especially where hydrothermal activity is concentrated. Thermogenic methane is more widespread, though not in the passive margin bordering the spreading centre. Despite the incidence of hydrocarbon generation and migration, the amounts of hydrocarbons involved are relatively small and apparently do not lead to commercially significant accumulations of petroleum.The organic matter in these sediments is mostly marine because the Gulf of California generally has low runoff from land and highly productive surface waters. Turbidites rich in terrigenous organic material are locally abundant in the mainly pelagic section in the Guaymas Basin. The highest concentrations of organic matter are found in laminated diatomites deposited on the Guaymas passive margin within the oxygen minimum zone.     

阻碍江苏滩涂开发速度的因素浅析

文章描述了江苏沿海滩涂开发存在的问题，分析归纳出影响滩涂开发速度的几个重要因素：领导重视不够；开发管理体制混乱；资金投入严重不足；科技投入减少，等等。并提出加速滩涂开发的几条措施，以企有所裨益。     

前苏联七十年海冰研究回顾

本文简要介绍了前苏联近七十年来海冰研究的主要成果及其采用的一些预报方法。     

东太平洋下中新统氧同位素地层与古海洋学意义

研究取自于东太平洋CC48柱状样的钙质超微化石和底栖有孔虫的氧同位素成分变化的结果表明,该区下中新统至少可分出九个氧同位素地层(期),反映该区在早中新世期间至少经历了4次气温上升和5次下降的古气候变化。南极大陆冰川应是形成于早中新世而不是前人认为的中中新世。在早中新世,南极冰体体积有较大的变化。受古气候变化的影响,在早中新世期间东太平洋水柱热结构或温度梯度有比较大的变化,海平面出现多次上升与下降。     

走航测深数据的自动采集

本文介绍应用IBM微机实现走航实时水深及定位数据的自动采集系统。给出了联机系统方框图及采集、传送数据的程序流程图。并对IBM-PC/XT微机与测深仪之间的接口、数码转换和数据处理作了简要的叙述。     

Northward transport of pacific summer water along the Northwind Ridge in the Western Arctic Ocean

The recent sea-ice reduction in the Arctic Ocean is not spatially uniform, but is disproportionally large around the Northwind Ridge and Chukchi Plateau compared to elsewhere in the Canada Basin. In the Northwind Ridge region, Pacific Summer Water (PSW) delivered from the Bering Sea occupies the subsurface layer. The spatial distribution of warm PSW shows a quite similar pattern to the recent ice retreat, suggesting the influence of PSW on the sea-ice reduction. To understand the regionality of the recent ice retreat, we examine the dynamics and timing of the delivery of the PSW into this region. Here, we adopt a two-layer linearized potential vorticity equation to investigate the behavior of Rossby waves in the presence of a topographic discontinuity in the high latitude ocean. The analytical results show a quite different structure from those of mid-latitude basins due to the small value of β. Incident barotropic waves excited by the sea-ice motion with large annual variation can be scattered into both barotropic and baroclinic modes at the discontinuity. Since the scattered baroclinic Rossby wave with annual frequency cannot propagate freely, a strong baroclinic current near the topographic discontinuity is established. The seasonal variation of current near the topographic discontinuity would cause a kind of selective switching system for shelf water transport into the basin. In our simple analytical model, the enhanced northward transport of summer water and reduced northward transport of winter water are well demonstrated. The present study indicates that these basic dynamics imply that a strengthening of the surface forcing during winter in the Canada Basin could cause sea-ice reduction in the Western Arctic through the changes of underlying Pacific Summer Water.     

弧后盆地的形成与演化探讨：以东亚陆缘区为例

通过对弧后盆地大地构造体制的讨论，作者认为基属活化作用的产物根据地质，地球物理，地球化学等资料的分析，作者提出结论认为，由于东亚岛弧系岩石圈的均衡作用及海沟外侧冷却大洋岩石圈块体的下沉拖曳牵引等作用，使软流圈在岛弧系下方发生分异，这种分异作用带动东亚陆缘向东扩张，从而产生弧后的张开。     

关于胶莱盆地东南缘基性火山熔岩喷发时代上限的讨论

首次对采自青岛即墨WN部两个深钻孔中新鲜玄武岩样品进行Rb-Sr同位素测年,测定年龄值为65.77±13.6Ma。认为该年龄值代表了胶莱盆地东南缘基性火山熔岩喷发的时代上限,对于整个胶莱盆地中基性火山岩的划分和对比具重要的年代学意义。