辽宁沿海泥炭堆积与全新世海面变化

辽宁沿海分布有丰富的泥炭资源，主要为埋藏泥炭，属于低位型的草本泥炭，按其成因可分为泻湖型，河漫滩型和沟谷型泥炭三种类型。     

中国北方全新世泥炭形成的初步研究(英文)

本文指的中国北方主要是包括华北和东北地区.该区泥炭分布较多,其中东北区多于华北区.据初步调查,东北区分布有裸露泥炭沼泽200多万公顷,埋藏泥炭约3万公顷,泥炭总储量约150多亿吨;华北区有裸露泥炭沼泽0.5万公顷,大部为埋藏泥炭,泥炭总储量约3亿多立方米.本区裸露与埋藏泥炭分布界线,大致是从辽宁省东南的岫岩以东起,经本溪、抚顺、西丰、伊通、双阳、榆树、巴彦、绥化、海伦、依安、富峪至科尔沁右旗,此线东北基本上为裸露泥炭沼泽分布区,而此线西南,主要为埋藏泥炭分布区,此线附近呈过渡状态.孢粉分析反映本区蕴藏泥炭的全新世地层古气候有三个演变过程,即从早期较冷较干,或较冷较湿,变得温暖潮湿,随后气温又变得偏凉偏干.古气候的演变导致沉积环境的变更,致使沉积相有三次较大的演变旋回,这在华北平原和沿海平原表现得尤为突出.在华北平原,全新世早期以河湖相为主,中期湖沼相普遍发育,晚期以冲积和洪积为主;在沿海平原某些地段,全新世早期为海陆过渡相,中期为海相,晚期又为海陆过渡相.北京和辽南一些地点泥炭自早全新世就开始沉积,东北平原中南部的泥炭多在中全新世形成,但都多在距今两千年左右被砂粘土或黄土状物质等埋藏.长白山、小兴安岭有的泥炭自中全新世沉积,但不少自晚全新世才开始沉积,均延     

海南岛红树林泥炭的海侵成因研究及其意义

本文在海南岛全新世红树林泥炭及其含沉积特特征，形成环境详细研究的基础上，对比会南晚更新世以来的海平面变化，综合分析得出：红树林泥炭形成于泥炭坪相；晚更新世晚期－全新世的快速海侵为含炭沉积的形成提供了古地理背景；红树林泥炭发育于４０００ａ以来的海平面波动上升时期；泥炭坪的发育主要取决于海平面的上升速度和植物有机质的堆积速度。海南岛全新世海侵成碳的研究为华北晚古生代含煤建筑的解释提供了比较沉积学的论据     

渤海湾沿岸泥炭沼泽形成机制与时空分布

渤海湾沿岸的海陆过渡带，优越的水文地理环境有利于泥炭沼泽的形成与发育。海洋海退导致的海岸线变迁，是控制泥炭沼泽发育时间和空间分布的主导因素。间冰期和冰后期的海面上升期间，自海向陆发育了海侵基底泥炭；中全新世高海面期，在山前扇缘洼地和沟谷有泥炭沼泽发育；晚全新世海面下降期，泥炭沼泽主要发育在沿岸的海湾、泻湖、三角洲汊河间洼地及平原上的河滩、阶地、古河道等地。     

广西沿海全新世以来气候变化

本文根据孢粉分析，有孔虫氧同位素分析，历史记载及现代气温观测资料，综合资料广西沿海全新世以来的气候变化，经过研究，初步划分了本区全新世以来的７个气候期，在晚全新世内，进一步划分了７个气候亚期，早全新世，中全新的气候变化具有１５００－２０００ａ周期，晚全新世界的气候变化具有５００－１０００ａ周期，晚全新世中－晚期的气候变化具２００ａ周期，２００ａ来的气候变化呈冷，热交替出现，具有１０－２０ａ或３０－     

三江平原沼泽发育与晚更新世末期以来古地理环境演变的研究

本文根据沼泽剖面的 ~(14)C测年、孢粉分析、粘土矿物X-衍射分析、植物残体鉴定和沉积物化学元素资料,研究了晚更新世末期以来三江平原沼泽发育与古地理环境演变。结果表明,沼泽发生及其发展与古地理环境演变有极其密切的关系。可分为四个时期:晚更新世末期沼泽孕育期,早全新世沼泽萌芽发育期,中全新世沼泽旺盛发育期,晚全新世沼泽继续扩大发育期。距今11000年左右应为本区晚更新世与全新世的分界。腐泥层底是全新统的下界。同江县勤得利农场十九队、抚远县创业队沼泽剖面可作为本区全新世的标准剖面。泥炭积累速率为晚全新世>早全新世>中全新世。     

闽南沿海若干全新世沉积物剖面的孢粉组合

闽南沿海全新世沉积物甚为发育,尤以海积物、冲积物和风积物最为多见,主要分布于海积平原和河口平原,厚度可达二十余米。我们对龙海九龙江河口平原和漳浦沿海平原做了重点研究,分析了高边头、塘内和下蔡等三个海积—冲积物和泥炭剖面的孢粉组合,结合已测的十几块贝壳、泥炭、木头、淤泥样品的C~(14)年龄,试对闽南沿海冰后期的植被演替、气候变化、海陆变迁和沉积发育的历史以及全新统的地层划分进行初步探讨,勾绘全新世环境变化的基本轮廓。     

浙江沿海~(14)C测年与全新世以来的海平面变化

本文对浙江沿海所采集的40个泥炭、贝壳、海滩岩、木头、淤泥和粘土样品进行了~(14)C年代测定。根据测定结果对浙江沿海全新世以来海平面的变化和全新世底界的年代进行初步讨论。     

江苏建湖庆丰剖面全新世气候变迁和海面变化

本文报道了江苏建湖庆丰剖面全新世地层研究新结果，提出了新的年代地层格架，建立了１万年来具有较高精度与分辨率的年均温与海面变化曲线．研究结果表明，金新世气温与海面均经历过７次明显的暖、冷与高、低波动；高温期出现于８．５～４．０ｋａＢＰ间，当时年均温普遍高于现今０．８～１．７℃；高海面时期出现于７．５～４．０ｋａＢＰ间，其中最高海面时期（６．５～４．０ｋａＢＰ）海面可高于现今２～３ｍ；气候变迁与海面变化均兼具区域性与金球性特征．     

3500年前夏威夷群岛北部海平面比现今高

全球海平面上升速率的新资料（２．１±１．３ｍｍ／ａ,Ｎｅｒｅｍ等,１９９７）在局部相对海平面的历史和组成中有长期的影响。两个重要的时期作为较温暖气候和海平面位置的模型,即１２５ｋａＢ．Ｐ．末次间冰期和５ｋａＢ．Ｐ．的全新世中期（Ｆｏｌａｎｄ等,１９９...     

Assessing the Validity of Seismo-Acoustic Predictor Equations for Obtaining Seabed and Sub-Surface Sediment Physical Properties

The interdependence between the seismo-acoustic properties of a marine sediment and its geotechnical/physical parameters has been known for many years, and it has been postulated that this should allow the extraction of geotechnical information from seismic data. Though in the literature many correlations have been published for the surficial layer, there is a lack of information for greater sediment depths. In this article, a desktop study on a synthetic seafloor model illustrates how the application of published near-surface prediction equations to subsurface sediments (up to several tens of meters burial depth) can lead to spurious predictions. To test this further, acoustic and geotechnical properties were measured on a number of sediment core samples, some of which were subjected to loading in acoustically-equipped consolidation cells (oedometers) to simulate greater burial depth conditions. For low effective pressures (representing small burial depths extending to around 10 meters subsurface), the general applicability of established relationships was confirmed: the prediction of porosity, bulk density, and mean grain size from acoustic velocity and impedance appears generally possible for the investigated sedimentary environments. As effective pressure increases through, the observed relationships deviate more and more from the established ones for the near-surface area. For the samples tested in this study, in some instances increasing pressure even resulted in decreasing velocities. There are several possible explanations for this abnormal behavior, including the presence of gas, overconsolidation, or bimodal grain size distribution. The results indicate that an appropriate depth correction must be introduced into the published prediction equations in order to obtain reliable estimates of physical sediment properties for greater subsurface depths.     

A Review of Some Environmental Issues Affecting Marine Mining

This article reviews information recently available from existing marine and coastal mining for responses to environmental issues affecting marine mining at different depths. It is particularly but not exclusively concerned with those issues affecting seabed biodiversity impact and recovery. Much information has been gathered in the past 10 years from shallow mining operations for construction aggregate, diamonds, and gold, from coastal mines discharging tailings to shallow and deep water, and from experimental deep mining tests. The responses to issues identified are summarized in a series of eight tables intended to facilitate site-specific consideration. Since impacts can spread widely in the surface mixing layer SML, and can affect the biologically productive euphotic zone, the main issues considered arise from the depth of mining relative to the SML of the sea. Where mining is below the SML, the issue is whether it is environmentally better to bring the extraction products to the surface vessel for processing (and waste discharge), or to process the extraction products as much as possible on the seabed. Responses to the issues need to be sitespecific, and dependent on adequate preoperational environmental impact and recovery prediction. For deep tailings disposal from a surface vessel, there are four important environmental unknowns: (1) the possible growth of "marine snow" (bacterial flocs) utilizing the enormous quantities of fine tailings particles (hundreds or thousands of metric tons per day) as nuclei for growth, (2) the possibility that local keystone plankton and nekton species may migrate diurnally down to and beyond the depth of deep discharge and hence be subjected to tailings impact at depth, (3) the burrow-up capability of deep benthos and their ability to survive high rates of tailings deposition, and (4) the pattern and rate of dispersion of a tailings density current through the deep water column from discharge point to seabed. Actions to obtain relevant information in general and site-specifically are suggested.     

Increased Particle Fluxes at the INDEX Site Attributable to Simulated Benthic Disturbance

Particle fluxes were measured 7 m above the sea bottom during the predisturbance, disturbance, and postdisturbance periods by using time series sediment traps attached to seven deep-sea moorings deployed in the INDEX experiment site in the Central Indian Basin. The predisturbance particle fluxes varied between 22.3 to 55.1 mg m -2 day -1 . Increased and variable particle fluxes were recorded by the sediment traps during the disturbance period. The increase observed was 0.5 to 4 times more than the background predisturbance fluxes. The increases in particle fluxes (~4 times) recorded by the sediment trap located in the southwestern direction (DMS-1) were the greatest, which could be the result of preferential movement of resuspended particles generated during the deep-sea benthic disturbance along the general current direction prevailing in this area during the experimental period. Also, the traps located closer to the disturbance area recorded greater fluxes than did the traps far away, across the Deep Sea Sediment Resuspension System path. This variability in recorded particle fluxes by the traps around the disturbance area clearly indicates that physical characteristics such as grain size and density of the resuspended particles produced during the disturbance had an important effect on particle movement. The postdisturbance measurements during ~5 days showed a reduction in particle fluxes of ~50%, indicating rapid particle settlement.     

海上大直径钢管桩打桩过程中桩周土强度弱化研究

海上大直径钢管桩打桩过程中,桩周土体受到强烈扰动而发生强度弱化,掌握桩周土体强度弱化规律对于准确预测打桩过程、保证工程安全具有重要意义。为研究土体强度弱化规律,开展了环剪试验模拟打桩对桩周土体的扰动,测试土体强度随剪切速率的变化规律,建立了描述土体强度弱化规律的拟合公式,引入到打桩分析软件中。研究结果表明：土体的强度折减程度不仅与土体本身的性质有关还受到土体的埋深和剪切速率的影响,埋深越深土体强度折减程度越低,剪切速率越高土体强度折减越高,在打桩分析中可采用这里推荐的线性折减方法来模拟不同深度处土体强度的折减规律。     

Determination of In Situ Sediment Shear Strength from Advanced Piston Corer Pullout Forces

The advanced piston corer (APC) has been used by the Ocean Drilling Program since 1985 for recovering soft sediments from the ocean floor. The pullout force measured on extracting the core barrel from the sediment is shown to correlate with the average shear strength of the sediment core measured in the ship's laboratory. A simple rule of thumb is derived relating the shear strength of the sediment to the pullout force. Multiple APC holes at individual sites allow the consistency of the pullout measurements to be assessed. The effects of different operational procedures during APC coring are also explored. Although generally applicable, the correlation between pullout force and laboratory measurements of shear strength breaks down for some APC holes, possibly because of the disturbance of some sediment types during the APC coring process. A better understanding of the physical process of APC coring, and its effect on the properties of the sediment both inside and immediately outside the core barrel, would indicate what confidence can be put on the measurement of pullout force as a way of evaluating the in situ shear strength of deep sea sediments.     

Interannual Sea Level Variations and Annual Tides in the Northwestern Pacific

Specific properties of the interannual sea level variations and annual tides in the Northwestern Pacific were studied. Several tide stations were monitored. The monthly mean sea level for the year of 1995 was analyzed at each tide station. A seismic event in 1995, some tectonic activity around the subject area, and the Kuroshio (the oceanic western boundary current) may possibly contaminate results which would have occurred from the astronomical annual tide alone.     

《Acta Oceanologica Sinica》Vol. 33(2014) contents

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INFORMATION FOR AUTHORS

<正>Acta Oceanologica Sinica(AOS)is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.The journal publishes scholarly papers on marine science and technology,including physics,chemistry,biology,