The First Colorimetric Characteristic of Bottom Sediments from the Chukchi Sea

Doklady Earth Sciences - The quantitative characteristics of the bottom sediment color of the Chukchi Sea is presented. The correlation relationships with the contents of grain-size fractions,...     

Mineral Features of Surface Sediments and Analysis of Solid-State Mineral Resources in Southeastern China Sea

INTRODUCTIONIn the past years,a few researches have been made intothe Quaternary surface sediments in vast range of the South-eastern China Sea.In November1 997,the Guangzhou Bureauof Marine Geology Survey,Ministry of L and and Resources,started the regional geological surveying and mapping of ChinaSea(“Shantoufu,F-50”) ,and the marine geology and geo-physics investigation in the Southwest Taiwan basin,and theEastern Pearl River Mouth basin and their adjacent areas.Inthese inve…     

渤海西部表层沉积物中重金属的环境地球化学特征

为探讨渤海西部在多重环境因素变化下沉积物中重金属的环境地球化学行为,分析了渤海西部44个站位表层沉积物样品中8种重金属元素含量,研究了重金属元素的分布特征、环境影响因素及其生态风险。结果表明,渤海西部表层沉积物中As、Cu、Cd、Cr、Hg、Ni、Pb、Zn的平均含量分别为117 mg/kg、255 mg/kg、014 mg/kg、689 mg/kg、0037 mg/kg、303 mg/kg、223 mg/kg、757 mg/kg;Cu、Cr、Ni、Zn含量与有机碳含量、小于63 μm细粒沉积物呈显著正相关,其在表层沉积物中的分布明显受到有机质含量和沉积物粒径的控制,而As、Hg分布没有明显受到有机质含量的影响。富集系数显示,Cr、Ni、Pb和Zn为无富集,Cu、As为轻度富集,Cd和Hg为中度富集。与多种背景值和一致性沉积物质量基准相比较,渤海西部表层沉积物Pb、Cd的含量超出背景值,而Cu、Zn、Ni、Cr、As、Hg含量也存在一定的异常,但其含量水平引发有害生物效应的可能性不大,尽管重金属元素含量偏高,但生态风险较小。     

The Heavy Metals Speciations in Bottom Sediments of Vyshny Volochek Reservoir

The water ecosystem of the Vyshny Volochek Reservoir is characterized based on the study of the distribution of heavy metals speciations in the solid phase and pore waters of bottom sediments. Using the sequential extraction procedure, it is shown that Mn is mainly present in exchangeable and carbonate-bound forms; significant roles for Fe, Zn, Pb, and Co are played by forms that are bound to iron and manganese hydroxides and Cu and Ni are mainly bound to organic matter. Thermodynamic calculations have established the prevailing share of the following forms in pore waters: free ions for Zn, Ni, Co, and Cd, carbonate complexes for Pb, and fulvic complexes for Cu. It has been revealed that the speciation forms of heavy metals in bottom sediments depend on the lithological features and content of organic matter in sediments.     

Sulfides of Bottom Sediments in the Northeastern Part of the Black Sea

Doklady Earth Sciences - A study of bottom sediments conducted on the 100th cruise of R/V Professor Shtokman in the northeastern part of the Black Sea along the section from the Kerch Strait to the...     

Implications of Color and Lightness Characteristics for Lithostratigraphy of Bottom Sediments from the Chukchi Plateau,Arctic Ocean

Marine sediment cores from the Chukchi Plateau are used to demonstrate the efficiency of digital photographic determination of sediment color and lightness, supplemented with the statistically processed data on sediment composition, for lithostratigraphy and paleoreconstructions. Several clusters were established that correspond to brown and gray sediment layers, carbonate-rich beige interlayers and specific segments of unclear lamination and/or lens-like intercalation of brownish and grayish beds. Correlation of the studied cores with other sediment cores from the region with well-established stratigraphy revealed good correspondence (though with certain specific features) to the conventional model of the Late Pleistocene–Holocene sediment accumulation in the offshore Arctic Ocean beyond shelf areas with clearly defined glacial–interglacial cyclicity. It was shown that enhanced red-color component corresponds to the enrichment of the interglacial brown sediment layers with manganese and accompanying elements. Glacial gray layers with enhanced green-color component are enriched in iron, as well as rubidium, vanadium, titanium and yttrium and bear evidence for considerable diagenetic transformations. Blue-color component is related to the high calcium content (carbonate rock fragments) in the carbonate-rich interlayers accumulated during the periods of active disintegration of continental ice sheets and iceberg-rafting of terrigenous lithic fragments. Intermediate values of the studied parameters are likely indicative of specific sedimentation environments.     

东海表层沉积物碎屑矿物组合分布特征及其物源环境指示

为进一步明确东海陆架区的沉积物物源及水动力环境,对研究区表层沉积物的碎屑矿物进行了鉴定分析。研究区共鉴定出49种重矿物、8种轻矿物。根据碎屑矿物的组合分布结合矿物形态特征,将东海陆架区划分为三个矿物区,内陆架矿物区、外陆架矿物区及虎皮礁矿物区。内陆架矿物区,动力分选是影响碎屑矿物分布的主要因素,物质来源相对单一,碎屑矿物主要来源于现代长江物质,闽浙沿岸近岸河流的输入,人类活动也对该区的矿物组成产生一定的影响;外陆架矿物区,重矿物分布的主控因素是长期的分选作用,主要是长江物质经后期改造形成,现代长江物质可从内陆架中北部扩散至124.5°E左右,此外外陆架东南部地形的变化也对碎屑矿物的分布起到一定控制作用;虎皮礁矿物区,有来自黄河、长江、火山物质的多重影响,且水动力环境相对复杂。     

The Structure and Long-Term Variability of the Bottom Layer in the Irminger Sea

This paper shows the important role that circulation can play in the long-term variability of thermohaline properties of the bottom layer in the Irminger Sea, and the increase in salinity in the 21st century in spite of intense ice melting in the Arctic and freshening of the upper and intermediate layers that started over the last 5–7 years in the North Atlantic.     

Clay Minerals in Bottom Sediments of the Medvezhii Island Region,Norwegian Sea

Integrated geological and geophysical investigation of bottom sediments in the Medvezhii Island region, southwestern margin of the Barents Sea, has made it possible to characterize sediments of diverse types related to the action of hydrocarbon fluids, hemipelagic sedimentation, slope phenomena, and combined influence of all these factors. Relatively homogeneous (in terms of mechanical composition) sediments are subdivided into several lithogenetic types based on the grain size distribution. Relationships of clay minerals, as well as their morphological and structural peculiarities, are described for each type. It is demonstrated that sediments formed under the substantial influence of hydrocarbon fluid fluxes are characterized by a high (relative to hemipelagic sediments) content of smectites and mixed-layer clay minerals of the illite–smectite series. It is assumed that these minerals are authigenic formations in mud volcanic rocks and diapir material. Based on the comparison of clay minerals contents primary source of the material for redeposited sediments has been reconstructed.     

Biogeochemical processes in the Chukchi Sea

Study of biogeochemical processes in water and sediments of the Chukchi Sea in August 2004 revealed atypical maximums of the concentration of biogenic elements (N, P, and Si) and the rate of microbial sulfate reduction in the surface layer (0–3 cm) of marine sediments. The C: N: P ratio in the organic matter (OM) of this layer does not fit the Redfield-Richards stoichiometric model. Specific features of biogeochemical processes in sea are likely related to the complex dynamics of water, high primary productivity (110–1400 mg C/(m² day)), low depth of basin (<50 m in 60% of the water area), reduced food chain due to low population of zooplankton, high density of zoobenthos (up to 4230 g m^?2), and high activity of microbial processes. Drastic decrease in the concentration of biogenic elements, iodine, total alkalinity (Alk), and population of microorganisms beneath the 0–3 cm layer testify to a large-scale OM decay at the water-seafloor barrier. Our original experimental data support the high annual rate of OM mineralization at the bottom of the Chukchi Sea.     

Aerosols in the Near-Water Surface Layer of the Caspian Sea

The first data on the concentrations, fluxes, and mineral and chemical compositions of aerosols from the near-water surface layer of the Caspian Sea are presented. It is shown that the aerosol fluxes onto the sea surface are comparable to the fluxes of a lithogenic substance in a water column. The mineral and chemical compositions of aerosols depend on the carrying air masses that pass through different regions. The coefficients of enrichment of aerosols with chemical elements relative to the upper lithosphere and their correlation relationships are studied.

     

Abundance and Chemical Speciation of Phosphorus in Sediments of the Mackenzie River Delta, the Chukchi Sea and the Bering Sea: Importance of Detrital Apatite

Utilizing a sequential extraction technique this study provides the first quantitative analysis on the abundance of sedimentary phosphorus and its partitioning between chemically distinguishable phases in sediments of the Bering Sea, the Chukchi Sea and the Mackenzie River Delta in the western Arctic Ocean. Total sedimentary phosphorus (TSP) was fractionated into five operationally defined phases: (1) adsorbed inorganic and exchangeable organic phosphorus, (2) Fe-bound inorganic phosphorus, (3) authigenic carbonate fluorapatite, biogenic apatite and calcium carbonate-bound inorganic and organic phosphorus, (4) detrital apatite, and (5) refractory organic phosphorus. TSP concentrations in surface sediments increased from the Chukchi Sea (18 μmol g⁻¹ of dried sediments) to the Bering Sea (22 μmol g⁻¹) and to the Mackenzie River Delta (29 μmol g⁻¹). Among the five pools, detrital apatite phosphorus of igneous or metamorphic origin represents the largest fraction (~43%) of TSP. The second largest pool is the authigenic carbonate fluorapatite, biogenic apatite as well as CaCO₃ associated phosphorus (~24% of TSP), followed by the Fe-bound inorganic phosphorus, representing ~20% of TSP. The refractory organic P accounts for ~10% of TSP and the readily exchangeable adsorbed P accounts for only 3.5% of TSP. Inorganic phosphorus dominates all of phosphorus pools, accounting for an average of 87% of the TSP. Relatively high sedimentary organic carbon and total nitrogen contents and low δ¹³C values in the Mackenzie River Delta together with the dominance of detrital apatite in the TSP demonstrate the importance of riverine inputs in governing the abundance and speciation of sedimentary phosphorus in the Arctic coastal sediments.     

克里雅河沿线沙丘沉积物石英砂表面特征分析

对沙漠内部典型河流沿线沙丘石英颗粒表面微形态特征的系统研究尚少。沿塔里木盆地南缘克里雅河下游丹丹乌里克、喀拉墩、圆沙古城、北方墓地及其北部塔里木河一带的沙丘顶部采到5件表沙样品。扫描电镜观察172颗经能谱挑选的石英颗粒表面微形态,筛析法测定5件样品的粒度。结果表明:1）丹丹乌里克样品以极细沙为主,其余均以细沙为主,各样品几乎不含黏土;2）样品磨圆度特征以次棱和次圆状为主,圆状很少,未见棱状特征,次棱状与次圆状特征之间消长关系显著,沙漠南北边缘样品的次棱状特征出现频率较腹地高;3）颗粒中V形坑频率呈现出沙漠边缘较高腹地低的特征,而沙漠边缘的化学作用结构特征低于腹地。石英砂表面特征结构以机械作用为主,同时伴生化学环境作用特征,可认为克里雅河下游沙物质包括了河流、冰川与戈壁成因及风输送而来的颗粒;颗粒表面特征总体新鲜,沙丘应较年轻。纵穿塔克拉玛干沙漠沉积物样品的表面微形态观察与粒度测定,为该地区沉积环境分析与沙丘砂溯源研究增添了新数据。     

Chemistry of Aerosols over Chukchi Sea and Bering Sea

The contents of elements in aerosols sampled during the First Chinese Arctic Research Expedition (CHINARE-1) show great differences from one element to another. Na, K,Ca, Mg, A1, F, and Cl are the major components in the aerosols, whose contents are larger than 30 ng/m^3. The chemical elements whose contents vary between 0.1 - 30 ng/m^3 are Br,Sr, Cr, Ni, and Zn. The chemical elements whose contents are close to or slightly higher than 0.1 ng/m^3 are Rb, Ba, Zr, Th, and Pb. The contents of As, Sb, W, Mo, Au, La, Ce, Nd,Sin, Eu, Tb, Yb, Lu, Sc, Co, Hf, Ta, and Cd are less than 0.1 ng/m^3. The mass concentration data for the same element, as observed during CHINARE-1, are almost accordant, but much lower than what is observed in the China‘ s seas or the coasts of China. The enrichment factor and electron microscopic analyses and lead isotope tracing were used to distinguish their sources.Four groups of sources can be classified as follows: anthropogenic: As, Sb, W, F, Mo, Au,Cu, Pb, Cd, V; crustal: La, Ce, Nd, Sm, Eu, Tb, Yb, Lu, Fe, Sc, Cr, Co, Ba, Zr, Hf,Ta, Cs, Mn, Th, U; oceanic:Na, K, Ca, and Mg; and mixing: Rb, Sr, Ca, and Mg.     

渤海东部与黄海北部表层沉积物的元素地球化学记录

为研究渤海东部及黄海北部海域沉积物常量元素组成特征及与物源的关系,分析了该海域138个站位沉积物样品的常量元素含量。渤海东部及黄海北部海域沉积物常量元素Al2O3、Mg O、Na2O和TFe2O3分布基本相似;Si O2分布与Al2O3、Mg O、Na2O和TFe2O3分布相反;Al2O3、Mg O、TFe2O3、Ti O2和Na2O等元素与细粒沉积物呈正相关,Si O2与粗粒沉积物呈正相关,Ca O、Ca CO3、Mn O和K2O分布与沉积物粒度无明显正或负的相关性;北黄海东部K2O分布反映了鸭绿江物质的影响。R-型聚类分析得出3种组合类型,以Mg O、Ca O和K2O及Mn O为代表,分别对应反映陆源细粒物质输入、指示黄河和鸭绿江物质的影响和海洋自生作用。依据Q-型聚类分析特征,将调查海域沉积物划分为4个不同的地球化学分区,同时综合分析得出了Ⅰ区、Ⅱ区、Ⅲ区和Ⅳ区的沉积物运移的路径趋势。K2O/Ca O揭示黄河物质影响自南至北和自西向东呈逐渐减弱的趋势,其中研究区西南部和北黄海中西部受黄河物质影响较强,北黄海东部沉积物更多受鸭绿江物质影响。     

Isotopic Composition of Nd,Pb, and Sr in Modern Bottom Sediments of the Barents Sea

Doklady Earth Sciences - The isotopic characteristics (εNd, 207Pb/206Pb, and 87Sr/86Sr) of the modern bottom sediments sampled in the Barents Sea during the 67th voyage of the R/V Akademik...     

长江口海域表层沉积物重金属元素赋存形态特征

通过长江河口地区水下表层沉积物样品多种化学元素的赋存形态分析测试数据,综合分析重金属元素的赋存形态特征。研究结果显示：镉、汞、铅残渣态所占比例均小于50%,锌、砷、铬、铜、镍残渣态占比均大于50%;8个元素的残渣态与全量呈显著正相关关系。沉积环境和沉积物粒径对重金属元素赋存形态具有重要影响。沉积物的物质来源、矿物组成特征、水动力作用与沉积物粒度和物理化学条件等是长江口地区表层沉积物重金属元素赋存形态的主要控制因素。     

南极普里兹湾表层沉积物微量元素分布特征及其物源指示意义

利用电感耦合等离子体质谱仪测定了中国南极科考21~27航次期间获取的普里兹湾表层沉积物中Cu、Pb、Zn、Cd、Cr、Co、Al、Fe、Mn的含量,分析了普里兹湾微量元素的分布特征,结合沉积物粒度分布、生物硅含量,并利用富集系数和主成分分析的方法,探讨了微量元素的物源指示意义。研究结果表明:普里兹湾沉积物中的微量元素含量与南大洋其他海域具有很好的可比性。Cu、Zn、Cr、Co、Fe、Mn含量在陆坡深海区明显高于冰架边缘区和陆架区;Al、Pb含量在冰架边缘区较高;而Cd含量在陆架区相对较高。人类活动对普里兹湾沉积物中的微量元素没有明显的影响,南极大陆岩石风化产物和海洋生物源性沉降是其主要来源。冰架边缘区及陆架破折处P2-9站位的微量元素主要为岩源性输入。陆架区、陆坡深海区的微量元素Cu、Zn、Cr、Co、Fe、Mn明显受到生源性物质输入的影响。而普里兹湾沉积物中Cd则主要来源于硅藻的吸收利用及硅质软泥的富集。     

南海西北部陆架表层沉积物稀有金属矿物及相关元素的分布特征与影响因素

对南海西北部近海陆架273个站位表层沉积物稀有金属矿物进行了研究,并结合沉积物粒度和沉积物类型,及与之相关的稀有金属元素分析,探讨了研究区稀有金属矿物的分布特征及主要影响因素。结果表明,本区沉积物中稀有金属矿物的分布主要受沉积物物源、沉积物类型和水动力条件等因素的控制,稀有金属矿物与相关元素的分布存在较大差异,不能仅凭沉积物中相关元素的质量分数分布来确定金属砂矿的有利富集或成矿区。根据沉积物中稀有金属矿物质量分数的分布特征及沉积环境分析,初步划分出5个稀有金属矿物富集区,分别对应于水东湾及附近海域、珠江口南外海、上下川岛与海陵岛之间外海、湛江湾及附近海域和海南岛东南近岸海域,且每个海域富集的稀有金属矿物种类有所不同,有望成为本区不同种类稀有金属砂矿的有利成矿区,其中钛铁矿、锆石和白钛石是本区最有成矿潜力的稀有金属矿种。