渤海湾中部表层沉积物中多环芳烃分布及其来源     

冉涛  李双林  张敏  张念礼 《海洋地质前沿》2014,30(12):30-35

通过对渤海湾中部海域19个站位表层沉积物样品中检测出的13种优控多环芳烃(EPAs)进行同分异构体、甲基菲、GC—MS定量等分析,探讨了研究区沉积物中多环芳烃分布特征、输入来源和污染水平,结果表明,研究区表层沉积物中多环芳烃总含量为2.1~374.8ng/g,平均值为33.1ng/g,多环芳烃总含量呈现出由近岸区向深海区递减的趋势,除最高值BG-60站位外,研究区与其他地区相比污染水平为中—低;化合物组成上以3~4环为主,5~6环次之,从多环芳烃组成以及异构体和甲基菲比值分析表明,研究区沉积物中PAHs以燃烧来源为主,石油类产品和石油化工燃料燃烧贡献最大,煤、木材燃烧贡献次之;高含量的菲和4个高成熟度异常点证实石油烃PAHs污染客观存在。  相似文献   

中国南海表层沉积硅藻的分布及其与环境关系探讨          下载免费PDF全文

孙美琴  蓝东兆  王遹其  薛蕾 《海洋科学进展》2014,32(4)

通过对中国南海62个站位表层沉积硅藻的分析,查明研究海区硅藻的种类组成及分布特点。共鉴定到硅藻56属的235个种(包括变种和变型),以热性外洋种为优势,伴有一定量的近岸广布种。总体上,南海硅藻丰度变化呈现从陆架向陆坡至海盆递增的趋势。根据表层沉积硅藻中具有指示意义的硅藻种的分布和生态变化,划分6个硅藻组合带,各组合分别反映不同的海洋环境,其分布主要受到海洋环流的影响,表现为黑潮暖流、印度洋暖水的入侵以及沿岸流对南海表层沉积硅藻分布的影响。与南海相邻海区硅藻种类比较结果表明,研究海区表层沉积硅藻种类组成与临近的菲律宾海域相似程度最大,其次是中国东海海域、太平洋东北部海域。  相似文献   

掺杂黏土矿物对沉积物吸持磷能力的影响     

胡秀芳  陈友媛 《中国海洋大学学报(自然科学版)》2014,44(2):89-94

通过研究黏土矿物及掺杂黏土矿物后湖泊沉积物磷的吸附/解吸特性,分析了高岭土、膨润土和沸石掺杂于湖泊沉积物后对磷稳定固定化的可行性。试验结果表明:掺杂膨润土稳定固化磷的效果最优,其次是高岭土,但掺杂沸石减小了沉积物对磷的吸附能力。具体结果是,按5%和10%比例掺杂高岭土时,沉积物吸附磷的能力增加,最大吸附量增加17.33%;按20%和40%掺杂时,沉积物吸附磷的能力减小,最大减小了43.31%。掺杂比例小时,高岭土与沉积物之间的阳离子交换过程扩大了空隙,增大了吸附量。达到平衡后,继续掺杂高岭土,引起空隙堵塞,减小了吸附量。掺杂膨润土的比例越大,沉积物吸持磷能力越强,按40%掺杂时,最终吸持率高达81.82%。这与膨润土表面积大、活性成分多有关。沸石由于孔道内被水分子和其他阳离子占据,有效吸附面积减小,对磷稳定化不起作用。  相似文献   

Distributions of surface sediments surrounding the Antarctic Peninsula and its environmental significance     

WANG Chunjuan  CHEN Zhihua  LI Chunshun  DU Dewen  YAN Shijuan  ZHU Zhiwei 《极地研究(英文版)》2014,(3):164-174

We analyzed grain size composition to provide information on the types and distributions as well as depositional varieties of marine surface sediments from the area surrounding the Antarctic Peninsula. The samples retrieved from the study area contain gravel, sand, silt and clay. As suggested by bathymetry and morphology, the study area is characterized by neritic, hemipelagic and pelagic deposits. The glacial-marine sediments can be divided into two types, residual paratill and compound paratill, which are primarily transported by glaciers and as ice-rafted debris. Ocean current effects on deposition are more obvious, and the deposit types are distributed consistently with terrain variations.  相似文献   

Sedimentary characteristics of relict deposits on the western South Yellow Sea     

WEN Chun  LIU Jian  WANG Hong  XU Gang  QIU Jiandong  and ZHANG Junqiang 《中国海洋大学学报(英文版)》2014,13(2):205-214

Integrated studies of vertical sedimentary sequences, grain sizes, and benthic foraminifera and ostracoda, in combination with AMS 14C dating, and 210Pb and 137Cs analysis were carried out in three vibracores taken from the area of relict deposits on the western South Yellow Sea. The relict sands, which are about 0.4 m thick, overlie on the Early Holocene coastal marsh or tidal flat deposits with an evident erosional interface in between. The middle and upper parts or sometimes the whole of the relict sands have been reworked under the modern dynamic environment. The sedimentation rate varies between 0.20–0.30 cm year-1. The relict sands show a bimodal grain-size distribution pattern in frequency curves, with a sharp peak in the coarse fraction between 3Φ and 4Φ and a secondary peak in the fine fraction of about 7Φ. Of the benthic foraminiferal and ostracod assemblages, the reworked relict sands are characterized by the mixing of the nearshore euryhaline shallow-water species and deeper water species. The erosional interface at the bottom of the relict sands is considered as a regional ravinement surface formed during the transgression in the Early Holocene due to shoreface retreating landwards. The relict sands were accumulated on the ravinement surface during the transgression in the deglaciation period as lag deposits after winnowing and reworking by marine dynamic processes. And the secondary peak of fine fraction in the frequency curve for the relict sands suggests the input of fine-grained sediments during the reworking process. As the conclusion, the relict sands in the study area are interpreted as a type of reworked relict sediments.  相似文献   

Response of microbial community to petroleum stress and phosphate dosage in sediments of Jiaozhou Bay,China   总被引：1，自引：0，他引：1  

ZHAO Yangguo  CHEN Min  BAI Jie  LI Xinwei  Farhana Zulfiqar  and WANG Qianli 《中国海洋大学学报(英文版)》2014,13(2):249-256

The dynamic microcosms were used to evaluate the effect of oil spills on microbial ecological system in marine sediment and the enhancement of nutrient on the oil removal. The function and structure of microbial community caused by the oil pollution and phosphate dosage were simultaneously monitored by dehydrogenase activity assay and PCR-denaturing gradient gel electrophoresis (DGGE) techniques. The results indicated that the amount of total bacteria in all dynamic microcosms declined rapidly with incubation time. The number of petroleum-degrading bacteria and the activity of sediment dehydrogenase were gradually enhanced by petroleum in the oil-treated microcosms, while they both showed no obvious response to phosphate dosage. In comparison, phosphate spiked heterotrophic bacteria and they showed a significant increase in amount. DGGE profiles indicated that petroleum dosage greatly changed community structure, and the bacteria belonged to class Deltaproteobacteria, and phyla Bacteroidetes and Chlorobi were enriched. This study demonstrated that petroleum input greatly impacted the microbial community structure and consequently the marine sediment petroleum-degrading activity was enhanced. Phosphate dosage would multiply heterotrophic bacteria but not significantly enhance the petroleum degradation.  相似文献   

R型因子分析和聚类分析在水系沉积物测量中的应用          下载免费PDF全文

魏印涛  何其芬  刘伟  陈宏杰  关琴 《山东国土资源》2014,30(10)

水系沉积物测量数据量庞大,如何有效的确定异常元素共生组合类型,是圈定异常的关键。利用R型因子分析和聚类分析,为青海省裕龙沟地区水系沉积物测量元素共生组合类型划分提供依据。利用划分的元素组合类型圈定组合异常,异常显示良好,套合程度高,充分证明了因子分析和聚类分析对划分元素组合的有效性。同时,R型因子分析和聚类分析二者可互相对照,增加划分元素共生组合类型的准确性。  相似文献   

基于离散余弦变换的集合Kalman滤波方法对河流相油藏渗透率场的反演   总被引：1，自引：1，他引：0       下载免费PDF全文

王玉斗  何健  李高明 《地球物理学报》2011,54(7):1900-1911

针对河流相油藏参数场的非高斯性及油藏生产数据与地质模型之间的非线性关系,提出了耦合离散余弦变换的半迭代集合Kalman滤波方法对河流相油藏进行生产历史拟合及反演.将河流相油藏非高斯渗透率场利用离散余弦变换变为类似高斯分布的DCT(Discrete cosine transform)系数,利用能量压缩特性对DCT系数进行...  相似文献   

Evaluation of the contamination of platinum in estuarine and coastal sediments (Tagus Estuary and Prodelta, Portugal)     

Cobelo-García A  Neira P  Mil-Homens M  Caetano M 《Marine pollution bulletin》2011,62(3):646-650

Platinum contamination in estuarine and coastal sediments has been evaluated in three cores collected from the Tagus Estuary and Prodelta shelf sediments. Elevated concentrations, up to 25-fold enrichment compared to background values, were found in the upper layers of the estuarine sediments. The degree of Pt enrichment in the estuarine sediments varied depending on the proximity to vehicular traffic sources, with a maximum concentration of 9.5 ng g⁻¹. A considerable decrease of Pt concentrations with depth indicated the absence of significant contamination before the introduction of catalytic converters in automobiles. Platinum distribution in the Tagus Prodelta shelf sediment core showed no surface enrichment; instead a sub-surface maximum at the base of the mixed layer suggested the possibility of post-depositional mobility, thereby blurring the traffic-borne contamination signature in coastal sediments.  相似文献   

Onshore-offshore gradient in reductive early diagenesis in coastal marine sediments of the Ria de Vigo, Northwest Iberian Peninsula     

K.J. Mohamed  D. ReyB. Rubio  M.J. DekkersA.P. Roberts  F. Vilas 《Continental Shelf Research》2011,31(5):433-447

Early diagenetic modification of magnetic properties is an important process in marine sediments, but temporal and spatial variability of diagenetic processes have rarely been reported for recent coastal sediments. The magnetic properties of sediments from the Ria de Vigo (NW Spain) define a marked three-part zonation with depth. The uppermost zone is magnetically dominated by (titano-)magnetite. In the intermediate zone, rapid down-core dissolution of (titano-)magnetite increases the relative influence of high-coercivity magnetic minerals, which react more slowly during reductive dissolution than (titano-)magnetite. This zone is characterized by the ubiquitous occurrence of framboidal iron sulphides. Pyrite is the dominant iron sulphide, but framboidal ferrimagnetic greigite is also frequently observed in association with pyrite. The lowermost zone is characterized by an almost complete depletion of magnetic minerals associated with progressive reduction of detrital iron oxides with depth. This zonation is controlled by organic matter diagenesis, which varies with water depth and wave-induced sediment resuspension and organic matter reoxidation in the water column. This leads to a shallowing and thinning of each zone with more intense reductive diagenesis toward the interior of the ria. Such a zonation seems to be a common feature in shallow water marine environments. If preserved, the described zonation and its spatial variability provide a potential tool for detecting estuarine-like environments in the geological record. Magnetic detection of current or past reductive conditions also has important implications for assessing paleoenvironmental proxies that are sensitive to diagenetic redox state.  相似文献