Sequence of the Cenozoic Mammalian Faunas of the Linxia Basin in Gansu, China

In the Linxia Basin on the northeast margin of the Tibetan Plateau, the Cenozoic strata are very thick and well exposed. Abundant mammalian fossils are discovered in the deposits from the Late Oligocene to the Early Pleistocene. The Dzungariotherium fauna comes from the sandstones of the Jiaozigou Formation, including many representative Late Oligocene taxa. The Platybelodon fauna comes from the sandstones of the Dongxiang Formation and the conglomerates of the Laogou Formation, and its fossils are typical Middle Miocene forms, such as Hemicyon, Amphicyon, Platybelodon, Choerolophodon, Anchitherium, and Hispanotherium. The Hipparion fauna comes from the red clay of the Liushu and Hewangjia Formations, and its fossils can be distinctly divided into four levels, including three Late Miocene levels and one Early Pliocene level. In the Linxia Basin, the Hipparion fauna has the richest mammalian fossils. The Equus fauna comes from the Wucheng Loess, and it is slightly older than that of the classical Early Pl     

石油污染地下水中细菌分子生态学研究

采集了某废弃炼油厂的石油污染地下水样品,提取水中微生物总DNA,构建细菌16S rDNA克隆文库,并通过16S rDNA序列的系统发育分析,对样品中的细菌种群多样性以及群落结构进行了研究。结果表明,文库中阳性克隆的16S rDNA序列分属11个细菌类群,分别为Betaproteobacteria(381％),Alphaproteobacteria(353％),Gamaproteobacteria(51％),Deltaroteobacteria(52％),Bacteroidetes(40％),Verrucomicrobia(25％),Epsilonproteobacteria(19％),Nitrospira(13％),Planctomycetes(13％),Candidate Division OD1(13％),Unclassified Bacteria(38％)。在这一生态系统中,Betaproteobacteria和Alphaproteobacteria类细菌占据主导地位,二者所占比例均在三分之一以上。群落中最主要的降解菌是噬氢菌属(Hydrogenophaga)和鞘氨醇单胞菌属(Sphingomonas)细菌,它们在文库中所占比例达239％和195％。该石油污染地下水样品中细菌与许多其他已知的降解菌亲缘关系较近,如Sulfuricurvum kujiense、Trichlorobacter thiogenes、Rhodoferax ferrireducens以及红细菌属(Rhodobacter)、甲基单胞菌属(Methylomonas)和涅瓦菌属(Nevskia)细菌等。此外,文库中克隆的16S rDNA序列与许多类似的污染场地中发现的环境克隆相似性很高,如煤焦油污染的地下水、苯污染的地下水、原油污染的土壤、溴甲烷和氯甲烷污染的土壤、抗生素生产废水以及活性污泥等,证明该石油污染地下水中有大量降解菌群的存在。石油污染物的种类对降解菌群的组成有一定的选择作用。     

20世纪80年代以来长三角地区综合交通可达性的时空演化

以1986、1994、2005年为时间断面,加权平均旅行时间为指标,长三角地区20世纪80年代以来综合交通网络及其可达性的时空演化呈现如下特征:①综合交通网络的快速发展带来了综合交通可达性的不断提升,且第二阶段(1994-2005)发展速度明显快于第一阶段(1986-1994);三时间断面上海及环太湖地区均为可达性最优区域,1986及1994年可达性较优区域大致由沪宁沿线和沪杭沿线构成>形,而2005则大致由沪宁沿线(含沿江地区)、沪杭沿线及杭甬沿线构成Z形;②可达性提升中节点获益具有明显区域差异,加权平均旅行时间初始值越高的节点其值下降幅度越大,加权平均旅行时间的变化率中部地区低于南北边缘地区,但变化值及变化率在不同阶段均呈现不同特征;③从分省市角度,上海可达性最优,江苏板块次之,浙江板块较差,但上海的优势地位逐步下降,浙江板块与江苏板块间的差距正不断缩小;④综合交通可达性系数标准方差逐步下降,表明长三角地区综合交通网络发育日益成熟,但不同交通方式具有不同发展特征。     

A high-resolution satellite-derived sea surface temperature climatology for the western North Atlantic Ocean

Long-term and high-resolution (∼1.2 km) satellite-derived sea surface temperature (SST) fields of a monthly mean time series for the 1985–1999 period, and a daily climatology have been calculated for the North West Atlantic Ocean. The SST fields extend from 78°W to 41°W in longitude, and 30°N to 56°N in latitude, encompassing the region off Cape Hatteras, North Carolina, to the southern Labrador Sea. The monthly mean time series, consists of 180 cloud-masked monthly mean SST fields, derived from a full-resolution NOAA/NASA Pathfinder SST data set for the 1985–1999 period. The satellite-derived monthly mean SST fields, as compared with in situ monthly mean near-surface ocean temperatures from buoys located in the western North Atlantic, yield an overall RMS difference of 1.15 °C. The daily climatology, which consists of 365 fields, was derived by applying a least-squares harmonic regression technique on the monthly mean SST time series for the full study period. The monthly mean and daily climatological SST fields will be useful for studying inter-annual variability related to climate variability of SST over the study domain.     

Nummulitic banks in the upper Lutetian ‘Buil level’, Ainsa Basin,South Central Pyrenean Zone: the impact of internal waves

Nummulites, a particularly abundant and diverse genus of larger benthonic foraminifera, formed huge accumulations (banks) during the Eocene, which are often good hydrocarbon reservoirs, especially in North Africa. Despite their economical interest, these accumulations are not well‐understood and their origin is still under discussion. Reasons for this debate are the absence of living Nummulites accumulations and the high‐variability of facies, including the size, shape and extension of the banks, which reflect the array of processes controlling sediment production and accumulation. The nummulitic banks near Santa María de Buil, in the Ainsa Basin (South Pyrenean Foreland Basin) are composed of recurrent facies associations within mappable bed units bounded by physical surfaces. The depositional processes that produced the Nummulites deshayesi accumulations are interpreted considering the shape of the banks, the type of bounding surfaces, the distribution of sedimentary textures, Nummulites test shapes and the associated skeletal components within the banks. This integrative analysis indicates that nummulitic banks accumulated from mass flows, with very poor sediment sorting. Textural and compositional differences among banks suggest that globose Nummulites thrived in the shallower part of the mesophotic zone with abundant nummulithoclasts, whereas flat nummulitic forms thrived in deeper mesophotic, clay‐dominated settings. Interbedded with nummulitic banks, coral biostromes and coral mounds bearing Operculina, Discocyclina and Asterocyclina, represent in situ accumulation near the base of the photic zone. Internal waves (waves that propagate along the pycnocline) are thought to be the triggering mechanism for the density flows. Internal waves and induced bottom currents are sporadic but strong enough to bring sediments into suspension. In contrast to surface waves (both fair‐weather and storm), whose impact is strongest near the sea surface and decreases with bathymetry, the impact of internal waves is usually strongest in the mid‐shelf region and weaker in shallow water. This explains the compositional character of the nummulitic banks.     

Lost in translation? Standardising the terminology used in marine invasion biology and updating South African alien species lists

Confusion between terms and ambiguities among definitions have long plagued the field of invasion biology. One result is disruption in flow of information from researchers to policy-makers and managers who rely on science to inform regulatory frameworks and management actions. We reviewed the South African marine biology literature to quantify the current usage of terminology describing marine invasions and found a variety of terms in use, few of which are defined when used. In response, we propose standard terminology that aligns with international practice. We then interpreted the Blackburn unified framework for biological invasions within the marine context and used this as a transparent way to apply the standardised terms to an updated list of marine alien species for the country. This resulted in the recognition of 36 alien and 53 invasive species within South Africa. Most notably, follow-up research is required to confirm the status of at least 11 listed species, the majority of which have been recorded only once, or not in the past 25 years. It is hoped that by standardising terminology, marine science in South Africa will better support authorities charged with managing the threat posed by marine alien species.     

Sedimentary evolution and environmental history of Lake Van (Turkey) over the past 600 000 years

The lithostratigraphic framework of Lake Van, eastern Turkey, has been systematically analysed to document the sedimentary evolution and the environmental history of the lake during the past ca 600 000 years. The lithostratigraphy and chemostratigraphy of a 219 m long drill core from Lake Van serve to separate global climate oscillations from local factors caused by tectonic and volcanic activity. An age model was established based on the climatostratigraphic alignment of chemical and lithological signatures, validated by ⁴⁰Ar/³⁹Ar ages. The drilled sequence consists of ca 76% lacustrine carbonaceous clayey silt, ca 2% fluvial deposits, ca 17% volcaniclastic deposits and 5% gaps. Six lacustrine lithotypes were separated from the fluvial and event deposits, such as volcaniclastics (ca 300 layers) and graded beds (ca 375 layers), and their depositional environments are documented. These lithotypes are: (i) graded beds frequently intercalated with varved clayey silts reflecting rising lake levels during the terminations; (ii) varved clayey silts reflecting strong seasonality and an intralake oxic–anoxic boundary, for example, lake‐level highstands during interglacials/interstadials; (iii) CaCO₃‐rich banded sediments which are representative of a lowering of the oxic–anoxic boundary, for example, lake level decreases during glacial inceptions; (iv) CaCO₃‐poor banded and mottled clayey silts reflecting an oxic–anoxic boundary close to the sediment–water interface, for example, lake‐level lowstands during glacials/stadials; (v) diatomaceous muds were deposited during the early beginning of the lake as a fresh water system; and (vi) fluvial sands and gravels indicating the initial flooding of the lake basin. The recurrence of lithologies (i) to (iv) follows the past five glacial/interglacial cycles. A 20 m thick disturbed unit reflects an interval of major tectonic activity in Lake Van at ca 414 ka bp . Although local environmental processes such as tectonic and volcanic activity influenced sedimentation, the lithostratigraphic pattern and organic matter content clearly reflect past global climate changes, making Lake Van an outstanding terrestrial archive of unprecedented sensitivity for the reconstruction of the regional climate over the last 600 000 years.     

海岸带研究中的点滴认识

人类对地球环境的影响已从罗马时期的局部影响步入了全球性的时代。一系列前所未有的全球环境问题,导致了地球系统科学的产生。面对全球变化,科学家提出了七大关键科学问题,其中之一就是:人类活动和土地利用的变化对于海岸带资源将会产生怎样的影响?未来气候变化和海平面变化将如何改变海岸带的生态系统,这是关系到人类生存和持续发展的大问题。于是IGBP提出了海岸带陆海相互作用研究的重大课题,是与其在地球系统科学中的地位和作用分不开的。     

Spatial patterns and environmental drivers of benthic infaunal community structure and ecosystem function on the New Zealand continental margin

To investigate regional drivers of spatial patterns in macro- and meio-faunal community structure (abundance, biomass and taxonomic diversity) and ecosystem function (sediment community oxygen consumption [SCOC]), we sampled two regions in close proximity on New Zealand's continental margin—the Chatham Rise and the Challenger Plateau. Sites (n = 15) were selected in water depths ranging from 266–1212 m to generate a gradient in sedimentary properties and, in particular, surface pelagic productivity. Both macro- and meio-fauna abundance and biomass was 2–3.5 times higher on the Chatham Rise than on the Challenger Plateau, reflecting regional differences in pelagic primary production. We also found significant inter- and intra-regional differences in macro-fauna taxonomic diversity with two distinctive site groupings in each region. Univariate and multivariate measures of macro-fauna community attributes were most strongly correlated with sediment photosynthetic pigment (explaining 24%–59% of the variation). Sediment pigment content was as equally important in explaining meio-fauna community structure (36%–7%). Unlike community structure, SCOC was most strongly correlated with depth (44%), most likely reflecting temperature effects on benthic metabolism. Our results highlight the importance of a benthic labile food supply in structuring infaunal communities on continental margins and emphasise a tight coupling between pelagic and benthic habitats.     

北阿尔金巴什考供盆地南缘花岗杂岩体特征及锆石SHRIMP定年

北阿尔金巴什考供盆地南缘花岗杂岩体呈近东西向分布,长约49公里,出露面积约90平方公里,与围岩之间为明显的侵入接触关系,接触界线为不规则的渡状、锯齿状。围岩为前寒武纪砂岩、片岩、泥岩及凝灰质砂岩。该杂岩体主要由巨斑花岗岩、红色花岗岩、灰白色似斑状花岗岩和粉红色似斑状花岗岩组成。杂岩体的主元素含量变化不大,SiO2为65．14％- 75．66％,全碱含量为7．49-8．96％,K2O／Na2O比值为1．12-2．68,岩石的里特曼指数平均为2．34,CIPW标准矿物计算均出现刚玉(AC)(平均为1．78),说明岩石铝过饱和;杂岩体的稀土总量变化于89．44×10-6-335．28×10-6之间,不同岩石类型均有负铕异常,且从巨斑花岗岩→灰白色似斑状花岗岩→红色似斑状花岗岩→红色花岗岩,负铕异常越来越明显,表现在Eu／ Eu+值由0．65→0．51→0．48→0．30。在微量元素蛛网图上,所有样品的微量元素丰度均高于原始地幔值,并具有相似的配分模式,即在Ba、Nb、Sr、P、Ti处呈明显的低谷,显示出S型花岗岩的特征。锆石SHRIMP U-Pb定年得出,巨斑花岗岩、红色中细粒花岗岩、灰白色和粉红色似斑状花岗岩的年龄分别为474．3±6．8Ma、446．6±5．2Ma、434．5±3．8Ma和431．1±3．8Ma。结合区域地质特征,我们认为,该杂岩体形成于同碰撞-碰撞后的构造环境。