《中国滨海砂矿》一书出版

该书是由地质矿产部海洋地质研究所矿产研究室谭启新、孙岩等编著,科学出版社编辑出版.本书是在“中国滨海砂矿分布及富集规律”研究报告的基础上撰写的.是我国第一部系统论述中国滨海砂矿的专著,它的出版必将对我国滨海砂矿的研究、开发起着积极的推进作用.书中汇集了我国目前已探明的具有工业价值的矿种12个,91处矿产地,矿床140个,矿点161个.对于形成滨海砂矿的物源条件、海岸及地貌类型、气候水动力条件、地质构造、新构造运动、海平面变化、第四纪沉积作用等成矿及控矿因素进行了系统的论述,进而总结了我国滨海砂矿成矿作用和成矿规律,建立了我国滨海砂矿的一般成矿模式,并就我国不同矿种的滨海砂矿成矿远景区划进行了论述和探讨.     

广西滨海地貌特征及砂矿形成的研究

广西滨海地貌,大体以饮州犀牛脚为界,东部以侵蚀一堆积的砂质夷平岸为主;西部则主要是微弱充填的曲折溺谷湾岸。滨海地貌与砂矿有直接关系。不同的地貌类型形成的砂矿床有所区别,一般砂矿床主要产于砂质海岸、沙坝—泻湖海岸、三角洲海岸内。生物海岸、泥质海岸不成矿。砂矿成矿与地貌形态相联的有海积的、冲积的、残积的、浅海的及混合的几种类型。砂矿的形成与富集多受地貌形态的控制。不同的地貌形态,砂矿富集的部位不一样,一般在沙堤的根部、海滩的高潮线附近、沿岸沙堤的上中部、水下沙坝的顶部和向海坡的上部,以及冲积平原的边缘地貌部位,容易形成砂矿和富集。区内滨海砂矿极其丰富,主要有北海白虎头玻璃石英砂矿床、江平澫尾锆石—钛铁砂矿床、巫头金红石—锆石砂矿床等。沿岸不同的砂矿种类与沉积物的粒级有不同的选择。钛铁砂矿产在中细砂—中粗砂中;玻璃石英砂矿产于中细至中粗级沉积物中。     

对我国滨海砂矿的一些基本认识

我国海岸线长达18000余公里,陆架宽广,蕴藏着较为丰富的滨海砂矿.近两年来,我们对全国滨海砂矿资料进行了系统收集、整理,对不同矿种选择了具有代表性矿区作了调查,对个别具有成矿远景的滨海区进行了重点的剖析,通过研究分析,对我国滨海砂矿的分布及其成矿特征有了基本的认识.本文从十个方面对我国滨海砂矿进行概要的论述.一、主要矿种及地理分布我国目前已探明具有工业价值的主要矿种有锆英石、钛铁矿、独居石、磷钇矿、金红石、磁铁矿、砂金、砂锡矿、铬铁矿、锯钽铁矿、石英砂等11种,发现各类砂矿床数十个,矿点、矿化点数百处,圈定浅海区重矿物异常42个,高含量区48个,已建立国营及地方矿山8处,民采点15处.其地理分布简述如下:     

我国滨海砂矿在第四系中的富集规律

滨海砂矿受海岸物质类型的控制具有呈带分布的特点.不同矿种的滨海砂矿,具有不同的成矿时代,在第四纪地层中有着不同的分布规律和富集特点,而且与地层的成因密切相关.     

开发我国滨海砂矿资源

滨海砂矿具有巨大的经济价值,它具有分布广、勘探、开采、选矿、冶炼方便等优点,受到滨海各国的重视,已成为世界上大部分独居石、锡石、锆石、钛铁矿、金红石的重要开采源。我国海岸线漫长、大陆架宽阔、岛屿众多,发育了各种不同的地质单元和地貌类型,有着良好的成矿条件,形成了丰富的砂矿资源。目前,从滨海砂矿中提取的矿物资源有钛铁矿、锆英石、独居石、金红石和磷钇矿、锡石、玻璃砂、型砂等。钛铁矿主要用于制造钛合     

广东和海南岛砂质海岸地貌及其开发利用

砂质海岸是广东和海南岛主要岸线类型,占岸线总长1/3以上,其规模取决于岸线轮廓、物质来源、海岸动力等因素。据不同动力过程、粒度、结构与历史的差别,从海向陆一般可分为海滩沙、岸堤沙,风积沙和晚更新世老红砂等不同沉积类型;据形态特点、沉积特征和分布情况,可将现代砂质海岸分为7种地貌类型。砂质海岸蕴藏着可供开发利用的资源,如沙荒地的改造利用、砂矿开采、海滨旅游、港口建设等。     

广西滨海砂矿特征及其富集条件

本省沿海地区砂质海岸发育,蕴藏丰富的滨海砂矿.有工业价值的砂矿床10处,矿点20余个.根据矿床形成的地理位置和矿床类型可划分为3个成矿区.这些矿床均形成全新世中、晚期的沿岸沙堤、海滩、水下沙坝中,个别砂矿床赋存于中更新世北海组冲积层中.     

中国滨海砂矿调查研究概况

我国地处太平洋西岸,有漫长的海岸线,宽阔的大陆架,发育了各种不同的海岸地貌类型,蕴藏着丰富的滨海砂矿资源.加强对这些矿产资源的调查,对国民经济的发展,具有现实意义.为了有助于了解和讨论我国滨海砂矿的一些基本特征,本文在前人工作基础上,结合近年课题研究工作,对我国滨海砂矿做一简单的回顾和讨论.     

西朝鲜湾二维潮流泥沙数值模拟与砂矿成矿分析

黄海西朝鲜湾是潮流流速特别高、潮流沙脊群明显发育的水动力沉积环境区,具有有利的砂矿成矿条件。为了分析其成矿特征,我们采用波浪潮流共同作用下潮流泥沙数值模拟的计算方法,模拟各级波浪下潮流、海底冲淤状态和全输沙量过程,由此分析按形成时代和主要分选控制因素划定的砂矿成因型和漂沙分选方式。本区砂矿属于潮流波浪控制的现代滨海砂矿,砂矿由潮流波浪掀沙、潮流输沙、风暴浪混沙进行平面及垂直分选形成,研究区类似一个巨型砂矿分选机,分选强度有利于砂矿成矿的地区大多为0～20m海域,矿层延伸到风暴浪最大冲刷范围之外。     

青岛地区滨海及浅海砂矿

青岛地区目前已探明小型滨海砂矿床１处，矿点数十处，浅海砂矿异常区２处，本文就其分布和特征进行了综述。     

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.     

Flow Cytometric Analysis of Coastal Lagoon Bacterioplankton and Picophytoplankton: Fixation and Storage Effects

The effect of different fixation and storage protocols on the flow cytometric (FCM) simultaneous analysis of bacterioplankton and phytoplankton in coastal seawater samples (Mediterranean coastal lagoons) was investigated. FCM measurements (cell number, fluorescence and scatter characteristics) were obtained through DAPI staining. Three fixatives [glutaraldehyde (GA), formaldehyde (FA) and paraformaldehyde (PFA)] and two storage (3 months duration) methods (5 °C and −196 °C) were tested. Two dominant populations were detected in studied samples: bacteria and eukaryotic picophytoplankton. Adding fixatives (2% final concentration) appears necessary to obtain FCM exhaustive counts of all the bacteria and phytoplanktonic cells. This was related to the permeation effect of fixatives which allowed a better DAPI staining of the cells. Maximum fluorescence, i.e. optimal staining of the cells was obtained with FA or PFA, and significant lower fluorescences with GA. Fixed samples stored at 5 °C induced rapid cell loss. Only storage in liquid nitrogen of samples fixed with FA or PFA, allows mid-term (≥4 months) preservation of bacteria or picophytoplankton cell numbers, and limited evolution of DAPI-induced fluorescence and scatter characteristics.     

《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,