南海南部SA09-040孔孢粉记录及古气候

依据南海低纬地区SA09-040孔高分辨率的孢粉记录,自下至上划分了4个孢粉组合带。从孢粉成分的变化,重建了22.25ka B P以来的植被与气候变化历史。结果表明:孢粉主要来源于婆罗洲和周围岛屿,孢粉1带(22.25～16.6ka B P),低山雨林植被发育,为暖热气候,从测年时间看,当时为末次冰期晚期。孢粉2带(16.6～10.82ka B P,为末次冰消期),植被以热带低山雨林和低地雨林为主,针叶的松数量较多,当时的气温比现在低。孢粉3带(全新世早期,10.82～6.43ka B P),植被以热带低山雨林和低地雨林为主,针叶松属数量减少,气温比前期升高,海平面也上升。孢粉4带(全新世中晚期,6.43ka B P至今),全新世中期为炎热、湿润的气候环境,全新世晚期可能与婆罗洲现今的植被景观相近,为热、湿的气候环境。     

Deriving regional vertical fluid migration rates offshore southwestern Taiwan using bottom-simulating reflectors

Fluid migration rates are important parameters for understanding the structural characteristics and evolution of the crustal tectonics and hydrocarbon exploration. However, they are difficult to measure on the seafloor. Densely sampled temperature measurements might shed light on our study of the fluid migration rates. In this study, we first use reflection seismic data to derive geothermal gradient patterns at different sub-seafloor depths, then calculated 1D vertical fluid flow models by analyzing the Péclet numbers in the offshore regions of SW Taiwan. We found Péclet numbers ranging from 2 to 5, implying that vertical fluid flow velocities are between 6 and 44 cm/year. Assumed a homogenous permeable layer and no lateral variation of the temperature fields, we analyzed possible errors caused by depth-dependent thermal conductivity and velocity-depth function. They probably cause less than 2 cm/year of errors in the estimated vertical fluid flow rate. In terms of regional fluid flow patterns, we found higher fluid flow rates near the toe of the trench, and a dramatic increase in fluid flow rate when the continental slope of the Chinese passive margin enters into the trench, and reduced fluid flow rates in the hinterland. We propose that this is a new and potentially useful method to derive regional fluid flow rate models for studying geochemical and biological processes in shallow seafloor sediments and the regional hydrological budget.     

福建近海五种主要捕捞作业适宜捕捞力量的研究

本文根据福建省定置、拖、围、刺、钓五种捕捞作业在本省近海的捕捞力量和渔获量,并以１９９４年单位功率的渔捞效率为基准进行逐年捕捞力量的标准化,应用Ｓｃｈａｅｆｅｒ和Ｆｏｘ两同电脑分别估算它们的ｆＭＳＹ和ＭＳＹ。结果两处在算的ｆＭＳＹ和ＭＳＹ的平均值是：定置网为８．９０尤明等３７．４１万ｔ;推网为５５．８８万ＫＷ,３５．５１万ｔ;为桃围网为７．１２万ＫＷ,１０．０６万ｔ;刺网为１５．１９万ＫＷ,９．５     

九龙江口鳗苗溯河生态与资源研究

九龙江口Ｌｉ苗１９９４￣１９９６年溯河期为１９９４年１１月２０至１９９５年４月底。１９９５年１２月２０日至１９９６年５月底。鳗苗溯河期水温范围１１．５￣２２．５℃,盐度１．９８￣２５．００,透明度０．２￣１．１ｍ,九龙江口打石坑－嵩屿断面溯河鳗苗资源量１９９５年１９３ｋｇ,１９９６年２０８ｋｇ;海澄断面１９９５年３５ｋｇ,１９９６年５５ｋｇ。     

A new species of the glass sponge genus Walteria (Hexactinell-ida: Lyssacinosida: Euplectellidae) from northwestern Pacific seamounts,providing a biogenic microhabitat in the deep sea

We report on a hexactinellid sponge new to science, Walteria demeterae sp. nov., which was collected from the northwestern Pacific seamounts at depths of 1 271–1 703 m. Its tubular and basiphytous body, extensive lateral processes, numerous oval lateral oscula which are irregularly situated in the body wall, the presence of microscleres with oxyoidal, discoidal and onychoidal outer ends, and the absence of anchorate discohexasters,indicate it belongs to the genus Walteria of family Euplectellida...     

Ophiuroid fauna of cobalt-rich crust seamounts in the Northwest Pacific Ocean

Seamounts are vulnerable ecosystems in the deep sea and can be heavily impacted by human activities, such as bottom fishing and deep-sea mining. The species composition and distribution patterns of benthic fauna is key information for the designation of marine protected areas and environmental management plans. Three contracts for cobalt-rich crust exploration have been granted to China, Japan and Korea in the Northwest Pacific Ocean by the International Seabed Authority. However, our knowledge ...     

海州湾潮间带大型底栖动物的分布特征

于2002年6月对海州湾3种底质的潮间带底栖动物进行了采样分析.结果显示,该区被鉴定出的大型底栖动物共有98种,其中多毛类为13种、软体动物为53种、甲壳类为25种、棘皮动物为2种、其它类动物为5种,软体动物和甲壳类的种类可占80%;该区潮间带大型底栖动物的平均生物量和平均栖息密度分别为257.30 g/m2和953个/m2,软体动物生物量(201.19 g/m2)和栖息密度(727 个/m2)分别占总数的78%和76%.经底栖动物种类相似性聚类分析和多维尺度排序,可将该区潮间带大型底栖动物划分为岩礁、沙滩和泥沙滩3个群落.通过对3个底栖动物群落的生态特征及相关环境因子分析得出:对于种类,泥沙滩群落 > 岩礁群落 > 沙滩群落;对于生物量、息栖密度、多样性指数和均匀度指数,岩礁群落 > 泥沙滩群落 > 沙滩群落;泥沙滩群落中的TE断面优势种分布显著而使多样性指数和均匀度指数明显低于其它两条泥沙滩断面.沙滩群落和岩礁群落的底栖动物分布分别与海水浴场和货运码头较多的人为活动影响有关,而泥沙滩群落的分布差异主要与海岸开敞度、海流潮汐作用、滩涂贝类养殖及优势种分布影响有关.泥沙滩是该区经济贝类的重要养殖场所,为使养殖种类健康生长,建议对沿岸排污口水质及养殖区沉积物环境质量进行定期监测.     

Pristine or altered: low-Mg calcite shells survived from massive dolomitization? A case study from Miocene carbonates

Low-Mg calcite shells have been widely used to reconstruct the chemistry of ancient seawater. There is always a question: are the shells chemically pristine? This paper presents the isotope and elemental geochemistry of low-Mg calcite bivalve shells in late Miocene platform carbonates, SE Spain. The platform carbonates were extensively dolomitized, and limestone is restricted to older stratal units, and to units mainly in topographically higher and more landward strata. Low-Mg calcite oyster shells were completely dissolved out in the basinward dolomite, but are well preserved in the limestone. These shells appear to retain the original growth microstructures, based on hand samples. Under the microscope, however, dissolution and recrystallization, as well as pristine growth lines are all present. Sr isotopes in these shells range from that of normal Miocene seawater to radiogenic values. δ¹⁸O and δ¹³C values, and Mg, Sr, and Na concentrations in these shells are rather variable. The high end members are consistent with the typical values of modern/late Miocene normal-seawater low-Mg calcite shells, whereas the low end members are close to those of diagenetic calcite cements, which have low δ¹⁸O, δ¹³C, Sr and Na values, and radiogenic Sr. The Nijar shells were altered physically and chemically to different degrees by diagenesis, although these shells are consistent with some “criteria” of unalteration. The isotopic and trace-element data collected in altered and pristine (or less altered) portions coexisting in the same shells are clearly differentiable. Quantitative simulation of covariations of geochemical pairs indicates that solid mixing of unaltered and altered portions by sampling is consistent with the variations in isotopic and elemental data recorded in the Nijar shells. The geological significance of this study is that ancient fabric-retentive calcite shells may have been altered geochemically although they may appear pristine. Calcite shells that underwent intensive diagenesis should be examined rigorously under the microscope, coupled with investigations of multiple geochemical proxies to assess chemical alteration. Only the data of unaltered shells can be used to reconstruct the chemistry of ancient seawater.     

无结构网格二维河口海岸水动力数值模式的建立及其应用

为完全拟合河口近海复杂岸线和工程结构以及有效局部加密,设计并建立了一个无结构三角形网格二维河口海岸水动力数值模式。空间离散主要基于有限体积法以保证守恒性,时间积分采用预估修正法以提高精度。水位在三角形网格中心通过连续方程求解;水平x方向和y方向的流速U和V均在网格边中点上通过动量方程求解。流速平流项的求解中采用了TVD格式。TVD流速平流通量为一个一阶迎风格式通量和一个二阶格式通量的组合,一阶格式通量和二阶格式通量根据流速的局部分布情况得出配比,最终组合得到TVD通量。TVD格式具有低耗散和无频散的优点,提高了模式的稳定性。应用实测资料验证建立的模式,结果显示水位、流速和流向的计算值与实测值均符合良好。     

退火对B掺杂纳米金刚石薄膜微结构和电化学性能的影响

采用热丝化学气相沉积法制备B掺杂纳米金刚石薄膜,并对薄膜进行真空退火处理,系统研究了不同退火温度对B掺杂纳米金刚石薄膜的微结构和电化学性能的影响.结果表明,当退火温度升高到800 ℃后,薄膜的Raman谱图中由未退火时在1157,1346,1470,1555 cm^-1处的4个峰转变为只有D峰和G峰,说明晶界上的氢大量解吸附量减少;并且D峰和G峰的积分强度比I_D/I_G值变为最小,即sp²相团簇