序言

台湾海峡及其邻区位于东亚活动大陆边缘重要地段,居于台湾俯冲带的弧后地带,东北面是冲绳海槽,西南是南海海盆。然而台湾海峡本身既非弧后盆地,又不是边缘海盆,又非裂谷带。台湾岛弧的俯冲带的俯冲方向又甚特殊,因之研究本区的构造特征及其演化历史,是岩石圈动力学和演化研究的一项重要内容,有助于活动板块边缘理论研究的深化,而对深部及浅层构造的了解,又有助于对本区的矿产资源,特别是能源、地热能的开发利用,以及地震预报和灾害的防止。     

菲律宾海板块东南边界地质过程与研究展望

晚中生代期间,由于古太平洋俯冲板片俯冲于欧亚板块之下,从而在欧亚大陆东缘存在一条巨型的类似于现今太平洋东侧的安第斯型俯冲带。岩浆活动记录显示,70 Ma左右,可能由于外来的正地形地体拼贴上该俯冲带,从而导致这条巨型安第斯型俯冲带逐渐消失,欧亚大陆东缘逐渐从主动大陆边缘变为被动大陆边缘。然而,新生代早期以来,伴随着菲律宾海板块从赤道北移,该被动大陆边缘又重新活化,变为主动大陆边缘,并逐渐形成了巨型的沟-弧-盆系统,期间西太平洋地区大致经历了三期的弧后扩张,即始新世、渐新世—中新世、上新世以来,且菲律宾海板块正好包括了这3个扩张期的弧后扩张盆地：西菲律宾海盆、四国海盆-帕里西维拉海盆以及马里亚纳海槽。本文详细总结了太平洋板块与次级的板块—菲律宾海板块及卡罗琳板块的地质演化历史,且详细探讨了以上3个主要板块之间相互作用的典型区域（菲律宾海板块东南侧）的地质学和岩石学特征以及尚存在的重要科学问题,并展望了未来该区域的研究方向。     

洋-陆转换与耦合过程

洋-陆转换/耦合地带就是大陆与大洋岩石圈转换/耦合的特殊构造地带。探索该区动力学对于深入理解人类密集区的地质过程具有重要的意义。这里洋-陆转换/耦合过程不是指陆壳向洋壳或陆幔向洋幔之间的物质转换,因洋壳向陆壳或洋幔向陆幔的物质转换过程也是不可逆的,而是特指构造动力作用或能量的转换交接过程。洋-陆转换/耦合带的狭义定义为被动大陆边缘的陆壳明显减薄到洋壳出现的深水区;但广义定义包括上述被动陆缘裂解作用涉及的区域范围,或是大洋岩石圈俯冲作用所能影响到的区域,其核心依然是俯冲带和/或大陆边缘,也就是说,其内涵是俯冲带和大陆边缘概念的总和,包涵浅部的地理要素和深部的地质因素。当前,对于洋-陆转换/耦合带的国际关注点很多,国际地学前沿问题较多,其中主要侧重以下几个方面:(1)物质:洋内弧形成与初始陆壳生成、俯冲脱水-相变、岩浆工厂、变质工厂;(2)结构:俯冲带类型、分段性、洋-陆转换/耦合带变形型式、地幔楔精细对流结构、俯冲面糙度-孔隙度-渗透率时空特征;(3)过程:俯冲过程、构造跃迁、构造转换、深部底侵、拆沉、高压-超高压岩石剥露、弧后扩张过程、板片窗、俯冲侵蚀与增生、物质迁移-转变-运聚、多圈层耦合过程;(4)机制:俯冲起源与板块机制起源、陆缘互换机制、地震触发机制、深部拆沉与底侵动力学机制、大陆裂解与(火山型和非火山)被动陆缘形成、洋-陆转换/耦合带构造跃迁机制、高压-超高压岩石剥露新机制、岩浆动力学、主动与被动俯冲机制、海山俯冲;(5)效应:源-汇效应、地表地形过程与深部流变关联、板片窗的构造-岩浆-成矿效应、边缘海盆地与资源-能源效应、俯冲与地震-海啸-滑坡灾害链。西太平洋和印度洋更是我国走向深海大洋、实现"海洋强国"的关键海域,蕴含着诸多中国的国家利益,也具有极其丰富的洋-陆转换/耦合过程的关键科学问题。现阶段可初步概括为以下几点:(1)板块重建的洋陆转换/耦合带检验;(2)深部过程(底侵-拆沉)与机制;(3)西太平洋陆缘构造体制和机制转换;(4)俯冲带分段性、过程与地震触发机制;(5)地表地形过程与深部流变、岩石圈强度关联;(6)地史期间的板片窗及其构造-岩浆-成矿效应;(7)洋陆转换/耦合带变形型式、构造跃迁和机制;(8)俯冲脱水、岩浆工厂与岩浆动力学;(9)边缘海盆地与资源、能源和灾害;(10)西太平洋板块格局与华北克拉通破坏;(11)太平洋板块格局与华南大陆再造;(12)印度洋过程重建与青藏高原隆升;(13)东亚地史期间的洋陆转换/耦合过程。     

琉球沟弧盆系及邻近海区的重力场和深部构造特征

依据以琉球沟弧盆体系为中心的重力异常图,本文进行了莫霍面计算、频谱分析、平滑滤波、解析延拓、水平求导、相关分析等多项计算处理,对照反射地震面进行分析讨论,以琉球海沟为界,两侧洋陆壳表现为明显不同的重力场和深部构造特征,由于俯冲的机制,使中国东部大陆边缘岩石圈结构复杂化,与大洋岩石圈为突变关系.     

我国台湾及其相邻海域构造特征

台湾岛位于亚州东海陆架边缘。是现代西太平洋沟-弧-盆系的组成部分,居于琉球弧与菲律宾弧的联接处,也是屹立在我国大陆的海岸山脉。从构造部位来看,它北接日本-琉球,南联菲律宾沟-弧-盆系。因此它是西太平洋活动大陆边缘的重要地区。     

大洋和大陆边缘岩石圈有效弹性厚度的研究意义

大洋岩石圈有效弹性厚度分布在 (45 0± 15 0 )℃等温面内 ,并且随着加载时岩石圈年龄的增加而增加。因此 ,大洋岩石圈的挠曲刚度强烈地依赖岩石圈的热结构。一些海隆下岩石圈有效弹性厚度的降低 ,可能是岩石圈经历过热活化 ,岩石圈热年龄降低的结果。大西洋一些群岛的岩石圈有效弹性厚度小于理论值 ,则反映了岩石圈结构的不同。在海沟 ,板块的挠曲也是影响岩石圈有效弹性厚度的因素 ,它降低了岩石圈的强度。在被动大陆边缘海陆岩石圈交界处 ,向陆的方向 ,岩石圈弹性厚度比同年龄的大陆或大洋岩石圈的小 ,表明强度明显降低 ;向大洋方向 ,岩石圈的弹性厚度与正常的大洋岩石圈弹性厚度吻合。在活动大陆边缘的挠曲前陆盆地和造山带 ,岩石圈有效弹性厚度变化较大 ,部分地区受先前的岩石圈低强度影响 ,而表现出岩石圈强度的弱化。同时 ,这种方法还广泛地用于大洋中脊岩浆侵位、地幔流动、南太平洋超级海隆的动力学机制、大陆边缘的变形和构造演化、新生岩石圈的力学性质和流变学性质的研究     

古巴蛇绿岩侵位

根据岩性和构造特征，古巴划分出三套含蛇绿岩的构造单元：1）北部蛇绿岩带，混杂岩复合体沿古巴岛延伸长度超过1000km；2）白垩纪火山弧建造的变质岩基底；3）中古巴南部Escambray（Guamuhaya）高压变质地块中的构造片体。现有年龄分析资料表明，古巴现存洋壳年代为晚中生代，形成于两种不同的构造背景；1）晚侏罗世-纽康曼期，北美大陆及其南部大陆的漂移造成的小盆地；2）北美被动大陆边缘与阿普第-阿尔必（Aptian—Albian）期火山弧之间形成的俯冲带上部（suprasubduction）边缘盆地。Escambary（Cuamuhaya）地块中生代变质沉积岩中的蛇纹岩片体和高压角闪石形成于一小型洋盆关闭期间．时代很可能为阿尔必（Albian）期。火山弧岩层的变质岩基底来自于上侏罗统-纽康曼阶洋壳，并在中自垩世火山弧形成期间发生变质。北部蛇绿岩带可能来自上述小盆地，以及俯冲边缘盆地的，并自晚白垩世坎佩尼（Campanian）期至始新世中期发生多次侵位。古巴不同的蛇绿岩类型代表了南北美大陆之间泛古陆解体后形成的洋壳的残余物（加勒比洋盆原型）。文章提出并讨论了一种可能的板块构造模型。     

东沙群岛海区晚新生代构造特征及其对弧-陆碰撞的响应

东沙群岛及其邻近海区(简称东沙海区)位于南海北部大陆边缘,东邻马尼拉俯冲构造带。为了讨论晚新生代以来东沙海区的构造变形特征,从中找出吕宋弧对中国东南大陆边缘碰撞的构造相关,特别是8Ma以来的吕宋岛弧和中国大陆边缘之间构造消减过程的响应。根据地震地层学分析,结合区域重磁资料、ODP184钻孔资料对东沙群岛海区晚新生代构造特征进行了分析。东沙海区自南海扩张后发育了3个沉积层序(层序Ⅴ,Ⅵ,Ⅶ),经历了较强烈的构造抬升作用、岩浆活动、沉积物剥蚀。该区发育NEE-SWW和NW-SE向两组断裂,且以NEE-SWW向断裂最为发育。断裂大多具有多次活动,且为上新世到第四纪的活动断裂构造,断块抬升幅度大,沿断裂带发生岩浆侵入。分析结果表明,晚新生代期间经历了二次重要的构造运动,即东沙运动(9．8-4．4Ma)和流花运动(1．89-1．4Ma),奠定了该区的构造格局。综合该区东强西弱构造变形、构造抬升发生的时间和应力场变化等特征看,该区受8Ma以来中国东部大陆边缘与吕宋岛弧碰撞所产生的构造运动的影响,在8Ma以前,由于台湾岛不存在,活动的古东海大陆边缘延伸至东沙群岛海区东北部。     

古巴侏罗纪和白垩纪地质演化史

古巴中生界的岩石特征是重建中美洲（墨西哥湾和加勒比海）地区地质历史的关键。古巴有4种不同类型的侏罗系-白垩系沉积剖面，其中3类来自不同的构造岩层带。四类岩性剖面由北至南分别为（1）中生界北美被动大陆边缘的一部分，具有很强的分带性，特别是古巴中部中白垩统地层；（2）北部蛇绿岩带，也包含上侏罗统-下白垩统巨型混杂岩体；蛇绿岩套的所有组成单元沿古巴北部发生构造混合；（3）火山弧岩层带，主要为自垩纪火山岩，含有年代较早的拉斑玄武岩为主的岩浆（阿普第阶-阿尔比阶）和年代较新的（森诺曼期-坎佩尼期）钙碱性火山碎屑和岩浆，其间有众多沉积岩夹层；阿尔比阶-森诺曼阶沉积物及少量火山岩将两个层序分隔开，有些地区存在上侏罗统-纽康曼阶火山弧的角闪岩基底；（4）南部变质岩层带，主要为在白垩纪经历了多期变质作用的中生界被动大陆边缘岩石。     

非洲热点火山现象：克拉通之下上地幔内的小型对流

克拉通是１０亿多年来未受构造运动影响的大陆区域。相对低的表层热流、金伯利岩内的金刚石包裹体以及约２５０ｋｍ深处具有高地震速度的比较冷而厚的龙骨状突起把克拉通与其它大陆岩石圈分开。虽然通常认为克拉通为地球岩石圈的稳定带 ,但是 ,岩石圈厚度的变化以及比后克拉通边缘处相对强烈的侧向温度和粘度变化仍然会引起克拉通边缘之下地幔中小规模的对流。研究表明这样的对流通常被称为边缘驱动对流 ,由一直延伸到克拉通边缘之下的地幔过渡带（大约６６０ｋｍ）的下降流和距离克拉通边缘大约５００～１０００ｋｍ处的上升流构成。上述研…     

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。     

Phylogenetic diversity and phenotypic characterization of cultivable bacterioplankton isolated from polar oceans

A set of 27 marine planktonic bacteria isolated from the polar regions was characterized by 16S rDNA sequencing and physiological and biochemical testing. More than half of these bacteria were positive for caseinase, gelatinase and 13-glucosidase, and could utilize glucose, maltose or malic acid as carbon source for cell growth. Twelve isolates expressed nitrate reduction activities. Except for one antarctic isolate BSwlO175 belonging to Actinobacteria phylum, these isolates were classified as γ-Proteobacteria, suggesting that γ-Proteobacteria dominated in cultivable marine bacterioplankton at both poles. Genus Pseudoalteromonas was the predominant group in the Chukchi Sea and the Bering Sea, and genus ShewaneUa dominated in cultivable bacterioplankton in the Prydz Bay. With sequence similarities above 97%, genus Psychrobacter was found at both poles. These 27 isolates were psychrotolerant, and significant 16S rDNA sequence similarities were found not only between arctic and antarctic marine bacteria （ 〉 99% ）, but also between polar marine bacteria and bacteria from other aquatic environments （ ≥ 98.8% ）, including temperate ocean, deep sea, pond and lake, suggesting that in the polar oceans less temperature-sensitive bacteria may be cosmopolitan and have a bipolar, even global, distribution at the species level.     

Estimation of Sediment Properties during Benthic Impact Experiments

Sediment properties, such as water content and density, have been used to estimate the dry and wet weights, as well as the volume of sediment recovered and discharged, during benthic impact experiments conducted in the Pacific and Indian Oceans. The estimates show that the weights of dry (355-1332 t) and wet sediment (1651-4888 t) recovered during the experiments, are not only a function of the total duration and distance covered during the experiment, but also depend on water content and density of the sediment. Estimation of dry sediment and its volumetric ratio in the discharge, are key parameters for calculating the discharged volume. The estimated volume of wet sediment recovered (1427-4049 m 3 ) as well as discharged (2693-6951 m 3 ) during the experiments, provide important inputs to evaluate the sediment resettlement and migration. Using these estimates, the average depth of excavation on the seafloor, can also been calculated. However, the stages of sediment recovery and discharge are expressed differently in some of the experiments. In order to standardize these, different stages have been identified, and definitions of certain terms have been suggested, for use in the future. The methods of calculating different properties, as well as weight and volume of discharged sediment are described in the paper for use in other applications concerning deep-sea discharges.     

A Tidal Flow Model for the Gulf of Kachchh, India

A vertically integrated model has been used to study the tidal circulation and currents in the Gulf of Kachchh along the west coast of India. The model is fully nonlinear and uses a semiexplicit finite difference scheme to solve the basic hydrodynamic equations on a staggered grid. The model is forced by prescribing the tides along the open boundary of the model domain. The flow is simulated both with and without the presence of the proposed tidal barrage across the Hansthal Creek in the Gulf of Kachchh. The results show a considerable change in the behavior of the tidal flow in the presence of the barrage.     

利用中国GF-3卫星SAR和HY-2A卫星微波散射计的首次台风联合定量观测

<正>The typhoon,as a mature tropical cyclone that develops in the western part of the North Pacific Ocean with high wind speed and heavy rainfall,is one of the most lethal and costly of natural disasters for the densely populated countries of East Asia.It can be easily detected by space-borne sensors operated at microwave,visible or infrared bands(Liu et al.,2014).Synthetic Aperture Radar(SAR)is     

离子交换—原子吸收光谱法测定海水中痕量铜、铅、锌、镉、铁、锰

本文介绍了用国产D401型螯合树脂分离富集海水中铜、铅、锌、镉、铁、锰等痕量元素,并用原子吸收光谱仪测定其含量的方法。讨论了各元素的分离条件选择及干扰元素的影响,并与溶剂萃取法的结果作了比较。各元素检测的定量下限为:铜0.5μg/L、铅0.1μg/L、锌1.0μg/L、镉0.01μg/L、铁2.0μg/L、锰2.0μg/L。方法精密度在4—8％之间,回收率为90—102％。     

Biogeochemistry of Mangrove Soil Organic Matter: a Comparison BetweenRhizophoraandAvicenniaSoils in South-eastern Brazil

Soil core samples fromRhizophora mangleL. andAvicennia schauerianaStapf & Leech forests from south-eastern Brazil were analysed for their total organic matter content and their sugars, amino acid and amino sugars composition. Organic carbon and nitrogen contents were higher inAvicenniathan inRhizophorasoils. The contribution of sugars and amino acids to the total organic carbon pool was constant with depth inRhizophorasoils whereas inAvicenniasoils it increased. Spectral distribution of sugars and amino acids showed a dominance of Ca-affine monomers, particularly acidic amino acids, and the sugar arabinose. Biogeochemical indicators derived from ratios of individual sugar and amino acid monomers confirm previous studies which showed that organic matter in both soils is mainly of mangrove origin. The results further suggest accumulation of organic matter inRhizophorasoils and a continuing degradation of organic matter inAvicenniasoils. The latter may thus release more nutrients to adjacent ecosystems thanRhizophorasoils.     

A review of orange roughy Hoplostethus atlanticus fisheries,estimation methods,biology and stock structure

Orange roughy Hoplostethus atlanticus are unusual fish. They form dense aggregations that have fuelled lucrative fisheries at great depths (600–1 400 m), especially off Namibia, New Zealand and Australia. They are thought to be very long-lived (>100 years, maturity at 22 – 40 years), and to have exceptionally low natural mortality (M = 0.045–0.064 year^?1) and slow growth rates (K = 0.055–0.070 year^?1). In addition, they spawn large eggs and have low fecundity. These factors combine to make orange roughy highly susceptible to overfishing; most stocks are below 30% of pristine levels. Assessments are obtained from indices of catch rate and trawl, acoustic and egg surveys. Acoustic estimates are the most direct, but are confounded by the species' low target strength (?50 to ?53 dB)–attributable to the wax-filled swim bladder. Extracellular wax esters are stored in abundance and comprise mostly mono-unsaturated fatty acids, with low concentrations of the ω-3 fatty acid family. This unusual composition (resultant from the species' diet) ensures neutral buoyancy. Stock separation has been inferred mainly from biological studies, but genetic studies have also found differences among stocks within New Zealand and Australia. Deep-water habitat may be damaged by trawling operations and may take many years to recover, so in some quarters there is a call for a portion of suitable habitat to be set aside for preservation. Although Namibian orange roughy are shallower, smaller and younger than those in other stocks, the Namibian fishery sustained high catches for only a few years before quotas were reduced, from 12 000 to 1 875 tons. Three management lessons are suggested for developing orange roughy fisheries based on the Namibian experience: (1) imposition of catch limits during exploratory fishing; (2) starting the acoustic surveys earlier in the fishery, if possible; (3) greater reliance on trends in catch rate until a survey series has been established.