深海沉积物分类与命名的关键技术和方案

对地质研究的对象进行科学合理的分类,是地学研究的重要内容之一.为建立科学合理、量化统一、操作简便的深海沉积物分类与命名方案,详细分析国内外深海沉积物分类与命名现状,深刻了解海洋沉积物组成与分布,深入研究深海沉积物的水深、平均粒径和粘土含量3项参数指标,通过分析涂片鉴定粘土、钙质生物、硅质生物这三者的含量、粒度和化学分析之间的差异,建立钙质生物、硅质生物与CaCO₃、生物SiO₂的量化关系,完成沉降法和激光法粒度分析资料的对比和校正,分析深海沉积物分类与命名的兼容性和可比性.在上述研究成果基础上,自主创新提出深海沉积物分类与命名方案及其关键技术.深海沉积物类型简分法把深海沉积物分为深海粘土、钙质软泥、硅质软泥、粘土-硅质-钙质软泥4类,它能满足一般性海洋地质调查要求,达到基本了解深海沉积物类型的目的,在兼容世界深海沉积物类型现状的同时,充分考虑到混合沉积物的存在.深海沉积物类型细分法在简分法基础上细分了16种沉积物,使分类与命名更加详细和全面,满足海洋地质详细调查研究的要求.深海沉积物分类与命名方案与浅海沉积物分类与命名比较,在图形、类型指标、种类数量、冠字冠名法、混合沉积物表示法、可操作性等方面具有可比性,使浅海到深海的沉积物分类与命名呈渐变和有机联系.      

深水碳酸盐沉积研究进展

深水碳酸盐沉积包括深水重力流作用形成的异地沉积和非重力流沉积，在非重力流沉积中又有深水牵引流(等深流、内波、内潮汐等)沉积和静态原地碳酸盐沉积。深水碳酸盐沉积与重力流及等深流活动有关，也受控于表层水碳酸盐产率、陆源物质的稀释作用及深水对碳酸盐的溶解作用。大量研究表明，深水碳酸盐沉积对海平面升降与气候变化响应明显，无论是重力流或非重力流沉积均有体现，通过深水碳酸盐沉积研究可以提取地质历史时期环境变化的信息，同时，某些深水碳酸盐沉积岩中蕴藏着丰富的石油、天然气和其他沉积矿产。由此开展此项研究具有重要的理论和实际意义。     

黄县盆地褐煤与油页央的泥炭沼泽类型分析

对黄县第三纪褐煤与油页岩共生盆地中煤1和油1的煤岩学特征及煤相参数特征的分析表明，黄县盆地煤1形成于较深覆水的森林沼泽，油1形成于湖泊沼泽，而海水侵入控制着盆地的覆水变化，进而影响了植物群落的演化与更叠。     

昆明盆地两孔岩芯的沉积特征及环境磁学分析

本文根据比较密的采样和磁化率测量,结合沉积特征、生物化石和沉积速率,分析了不同沉积环境沉积物的磁化率数值及沉积相变所表现出的磁化率曲线的形态特征.     

黄县盆地褐煤与油页岩的泥炭沼泽类型分析

对黄县第三纪褐煤与油页岩共生盆地中煤₁和油₁的煤岩学特征及煤相参数特征的分析表明,黄县盆地煤₁形成于较深覆水的森林沼泽,油₁形成于湖泊沼泽,而海水侵入控制着盆地的覆水变化,进而影响了植物群落的演化与更叠。      

南海西南海域表层沉积物中微量元素Ba的地球化学特征

分析南海西南海域表层沉积物中微量元素Ba的地球化学特征,并探讨生物成因Ba的分布及其与表层海水生产力的关系。南海西南海域表层沉积物Ba总量的变化范围为398~1 270 μg/g,平均值为851 μg/g,从上陆坡到下陆坡,沉积物中的Ba含量逐渐增加;微量元素Ba主要赋存于陆源碎屑相和生物成因相中,且明显受到沉积环境水深和陆源物质输入的影响。生物成因Ba含量的变化范围为30.6~938 μg/g,陆坡区和深海区平均值分别为495 μg/g、349 μg/g,占沉积物Ba总量的54％和51％,总体上,与沉积物Ba总量具有相对一致的分布特征。尽管研究区表层沉积物中Al、Ti成分为典型的陆源碎屑组分,但是,利用大陆上地壳Ba/Al比值和陆坡区沉积物回归分析获得的Ba/Al比值进行生物成因Ba的计算,过高地估算了沉积物中陆源Ba的含量;而采用页岩Ba/Ti比值来估算陆坡区表层沉积物中的生物成因Ba含量显得相对可靠。在深海区,利用经验的Ba/Al或Ba/Ti比值均不能获得有效的生物成因Ba值。因此,在获取沉积物中生物成因钡含量时,需结合各海区的特点选取合适的参数来扣除陆源Ba的含量。     

加速器质谱分析超痕量铍同位素研究深海沉积物沉积速率和多金属结核生长速率

用加速器质谱测定１０Ｂｅ同位素，研究深海沉积物和多金属结核中１０Ｂｅ同位素的含量分布，获得相关的地质年代、沉积速率和生长速率。     

深海浅表层沉积物不排水剪切强度的多探头原位测试系统及评价方法研究

海洋工程建设已步入深海,但与之匹配的浅表层沉积物不排水剪切强度原位测试技术尚不成熟。为此,本文开发了可用于评估深海浅表层沉积物土力学性质的多探头原位测试系统,包括锥形触探仪、球形贯入仪和十字板剪切仪,可实现对深海沉积物土力学性质的快速、准确和智能化评价。进一步,通过CEL大变形数值模拟和足尺土工模型试验确定锥形触探仪的锥尖阻力系数,基于离心模型试验给出球形贯入仪的贯入阻力系数,从而完善深海浅表层沉积物不排水剪切强度的评价方法;在此基础上,探讨3种特定仪器各自适合的强度测试区间。结果表明:对于深海浅表层沉积物不排水剪切强度的评估,锥形触探仪和球形贯入仪的阻力系数建议分别取值为9.5和11.1。     

深海相中的砂质碎屑流沉积--以西藏特提斯喜马拉雅侏罗-白垩系为例

阐述了砂质碎屑流沉积特征、研究现状及其与其他深海碎屑沉积的区别 ,认为西藏特提斯喜马拉雅上侏罗统 -下白垩统深海沉积背景下的块状砂岩具有砂质碎屑流沉积性质 ,指出深海相中的块状砂岩可以预测。     

西藏沙丁、荣布地区三叠系—老第三系沉积地质特征

研究区从三叠纪到老第三纪,发育的岩石地层主要有确哈拉群（Ｔ３）、希湖群（Ｊ１－２）、拉贡塘组（Ｊ２－３）、多尼组（Ｋ１）、竟柱山组（Ｋ２）和牛堡组（Ｅ２－３）。在沉积相上,经历了从深水沉积到浅水直至陆相沉积的演变,发育有冲积扇、河流、湖泊、三角洲（潮汐）、障壁海岸、浅海、深海和火山碎屑流沉积。古地理分析表明,研究区晚三叠世古地理轮廓是一个从东南向西北和东北方向由浅水碳酸盐台地及深水陆层海底扇沉积共同发育的沉积盆地;早中侏罗世,演变成为一个由深水砂质浊积岩和细屑浊积岩组成的水下席状体沉积;进入中晚侏罗世,其古地理表现为一个陆屑浅海有障壁海岸;到了晚白垩世,研究区表现为以含煤沉积为特征的三角洲相沉积。     

Extreme Enrichment of Tellurium in Deep-Sea Sediments

Tellurium is a sort of scattered rare element on the earth. Its concentration is very low in earth＇s crust, only 1.0 ng/g. However, it has extremely high abundance in Co-rich crusts, marine polymetallic nodules, deep-sea sediments and aerolites. To find out the origin of tellurium enrichment in deep-sea sediments, we analyzed and compared tellurium concentrations and helium isotope compositions in the magnetic parts and those in the bulk parts of deep-sea sediments. The result indicates that the helium content, 3He/4He ratio and tellurium concentration are obviously higher in the magnetic parts than those in the bulk parts. The 3He abundance varies synchronously with the tellurium concentration. 3He and Te have a distinct positive correlation with each other. It is the first time that the paper brings forward that the extreme enrichment of tellurium in deep-sea sediments, like helium isotope anomalies, probably results from the input of interplanetary dust particles （IDPs）. Similarly, the extreme enrichment of tellurium in marine polymetallic nodules and Co-rich crusts is possibly related to IDPs.     

洋山港海域现代沉积物运移趋势

地形、物源和水动力条件是洋山港海域现代沉积环境的主要控制因素，粉粒和粘粒是现代沉积物的主要组成部分，潮流是起动和搬运现代沉积物的主要动力，悬移是现代沉积物最主要的搬运方式，跃移是次要搬运方式，现代沉积物的起动和沉积过程交替频繁。研究区现代沉积物长期净运移趋势表明：研究区东部的黄泽洋向洋山港海域的输沙趋势显著；洋山港岛链峡道深槽的形成，系由峡道东部和西部的现代沉积物各向峡道两端分异运移所致；小洋山—唐脑山—线将是今后港区泥沙淤积的主要部位之一。     

Freshwater chlorophycean algae in recent marine sediments of the Beaufort, Laptev and Kara Seas (Arctic Ocean) as indicators of river runoff

Freshwater chlorophycean algae are characteristic organic-walled microfossils in recent coastal and shelf sediments from the Beaufort, Laptev and Kara seas (Arctic Ocean). The persistent occurrence of the chlorophycean algae Pediastrum spp. and Botryococcus cf. braunii in marine palynomorph assemblages is related to the discharge of freshwater and suspended matter from the large Siberian and North American rivers into the Arctic shelf seas. The distribution patterns of these algae in the marine environments reflect the predominant deposition of riverine sediments and organic matter along the salinity gradient from the outer estuaries and prodeltas to the shelf break. Sedimentary processes overprint the primary distribution of these algae. Resuspension of sediments by waves and bottom currents may transport sediments in the bottom nepheloid layer along the submarine channels to the shelf break. Bottom sediments and microfossils may be incorporated into sea ice during freeze-up in autumn and winter leading to an export from the shelves into the deep sea. The presence of these freshwater algae in sea-ice and bottom sediments in the central Arctic Ocean confirm that transport in sea ice is an important process which leads to a redistribution of shallow water microfossils.     

南海西部浮游有孔虫含量与水深关系定量研究

南海西部4°～18°N,1085～115°E海域表层沉积物中有孔虫定量分析表明,从陆架至深海盆区,随着水深增加,底栖有孔虫丰度总体呈下降趋势;而浮游有孔虫在上陆坡区水深200～2 000 m处最丰富,向浅水和深水方向,其丰度均下降,浮游有孔虫百分含量（P）与水深（D）有明显的相关关系。但在陆架区和陆坡－深海盆区,两者关系完全不同：在陆架区随水深增加浮游有孔虫百分含量明显增大,而在陆坡－深海盆区,两者呈负相关关系。经定量拟合水深小于200 m的陆架区,浮游有孔虫含量与水深满足关系式：lnD＝0.021P＋3.208;而在水深大于200 m的陆坡－深海盆区,两者满足D＝－5263P＋52 105.2。这主要是由于陆架区随水深增加,浮游有孔虫增加,但水深大于200 m后,碳酸盐的溶解起主要作用,浮游有孔虫比底栖有孔虫更易于溶解,造成其含量随水深增加而下降。     

广西钦州石炭-二叠纪深海硅质岩的锶同位素组成及其地质意义

报道了广西钦州海槽早石炭世-早二叠世深水硅质岩的锶同位素测定结果和经年代校正后的87Sr/86Sr初始值,建立了锶同位素演化曲线;通过与同时代上扬子地区台地相碳酸盐岩87Sr/86Sr比值和演化曲线的对比,研究了二者的异同和造成差异的原因。深水硅质岩和同期台地相碳酸盐岩的锶同位素演化曲线在总体特征上具有一定的相似性,反映海平面变化对其影响的一致性。玄武岩喷发等局部事件和硅质岩中无法回避的陆源碎屑的影响是造成87Sr/86Sr比值和演化曲线差异的主要原因。硅质岩锶同位素演化曲线显示,海平面上升发生于早石炭世,在晚石炭世早期达到最大值,晚石炭世晚期,海平面有所下降,在其后的早二叠世,海平面再次上升。     

Late Holocene Tectonic Uplift and the Silting Up of Lechaion,the Western Harbor of Ancient Corinth,Greece

Lechaion's ancient harbor is now a coastal swamp filled with sediments. Two natural factors explain the harbor's abandonment: (1) tectonic uplift during historical times and (2) the location of the harbor basin in a serpentine depression protected from the sea. Although it undoubtedly functioned as a very efficient sediment trap, only modest sedimentation rates (<1 mm/yr) have been measured in the basin. This paradox suggests that the basin was dredged and that the extracted sediments were dumped, forming a number of mounds around the harbor edges. The transition from marine organics to silt is dated to 750–400 cal. B.C. and precedes the 1.2 m uplift of the harbor at around 340 B.C., which underscores the minimal impact of tectonic forcing factors. The presence of fine‐grained sediments is consistent with an increasingly protected environment. The macrofauna indicate a low‐energy environment enriched with organic matter and brackish conditions. All data suggest that this environment became isolated from the sea. Although a seismic uplift around 340 B.C. played a partial role in the evolution of the harbor, it is not the sole natural forcing agent involved in the silting up of the basin. © 2012 Wiley Periodicals, Inc.     

Acyclic archaebacterial ether lipids in swamp sediments

Acyclic phytanyl diether glycerol and biphytanyl ether lipids have been quantified in two modern swamp sediment cores in concentrations ranging up to 360 μg/ml porewater. Methanogenic bacteria are the only known source organisms which can inhabit the swamp sediments. Variations in relative abundance between these lipids may reflect taxonomic changes in methanogen populations or the stage of growth. Maxima in methanogen lipid concentrations coincide with local maxima of ¹³C of organic matter, possibly the result of a pool effect on CO₂ or acetate. Methane production estimates calculated from lipid concentrations in swamp sediments range from 0.1 to 1.3 mmol cm⁻² yr⁻¹, values which are consistent with published methane fluxes.     

中国海域表层沉积物分布规律及沉积分异模式

中国海域拥有宽广的大陆架，同时还有陆坡和深海盆，有众多河流入海并输入巨量的陆源物质，沉积物记录了海陆变迁、环流变化、海平面升降、物质输送和气候变化等环境信息。沉积物的粒度特征可以反映沉积动力、物质来源和搬运距离等，可以通过沉积物粒度组成、参数及各种图解来研究沉积环境的变化。前人对中国海域表层沉积物的粒度分布特征展开了大量的研究，取得了丰富的研究成果，但这些研究多集中在某一海域或区域，缺乏对整个中国海域的表层沉积物类型的宏观系统认识。本文基于中国地质调查局“1：100万海洋区域地质调查项目”获取了中国海域4300个海底表层沉积物样品，通过沉积物粒度分析，结合前人已发表资料，对中国海域表层沉积物的沉积类型特征、物质来源和运移模式等开展了系统的研究。本文把浅海和半深海沉积物按照含砾石和不含砾石主要划分出5个和7个沉积物类型，深海沉积物主要划分了9个沉积类型，研究结果表明：中国海域表层沉积物沉积类型多样、来源复杂，主要受控于物质来源、水动力条件和地形地貌的变化，在东部海域总体呈现“大江大河-宽缓陆架-残留慢速沉积”的条带状沉积分异模式，而在南部海域呈现的是“短源性河流-多类型陆架-重力流快速沉积”的环带状沉积分异模式。本文的结果对研究中国海域沉积物的宏观分布规律提供了基础资料，对理解海洋沉积动力过程具有重要意义，同时沉积物粒度的特征对海底砂矿分布也具有指示意义。     

Composition of organic matter in subducted and unsubducted sediments off the Nicoya peninsula, Costa Rica (ODP Leg 170, Sites 1039 and 1040)

Investigation of sediment samples from Sites 1039 and 1040 (ODP Leg 170) drilled off the Nicoya peninsula (Costa Rica) by organic geochemical and organic petrological methods has revealed that subduction has only little influence on the composition of the sedimentary organic matter. Organic carbon contents reached 1.5% in the Pleistocene samples but Miocene and Pliocene sediments had an average organic carbon content of less than 0.5%. Organic carbon/sulfur ratios are generally below 2.8, reflecting an intense sulfate reduction in the uppermost sediments which was enhanced by sulfate supply both from sea water and deeper strata. Microscopical examinations indicate that the organic matter is mainly derived from marine sources. A small amount of terrigenous organic matter is, however, present as well according to n-alkane and fatty acid distributions. The alkenone unsaturation index U₃₇^k′ shows only a slight decrease during the Miocene and Pliocene, and stronger variations in the Pleistocene, probably indicating more stable sea surface temperatures during the Miocene and Pliocene. Variations in the Pleistocene can possibly be related to glacial/interglacial changes.     

华北陆台晚古生代岩相古地理

位于天山-阴山、昆仑山-秦岭两大纬向构造带之间的华北陆台。在稳定地壳基底上逐渐发展形成晚古生代多旋回克拉通大型含煤盆地。加里东运动使陆台缺失O₃-C₁沉积，晚石炭世至晚二叠世陆台为海陆交互相滨海、湖泊、三角洲沉积，随着古地理环境演变,陆台各沉积古地理环境在时、表现为由老至新、自北向南迁移。