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 共查询到20条相似文献,搜索用时 171 毫秒
1.
Analysesonthephysio-psychologicalstateoftheexpeditionersinAntarcticaZhangWencheng(张文诚);WuWen(巫雯)andYuYongzhong(于永中)(BeijingIn...  相似文献   

2.
ThechemicalcharacteristicsofseawaterinthePrydz Bay,AntarcticaWangYuheng(王玉衡);DengHengling(董恒霖)andRenDianyong(任典勇)(SecondInsti...  相似文献   

3.
赵烨  李天杰 《极地研究》1996,7(1):70-78
(赵烨)(李天杰)ThepedogenicgroupsanddiagnosticcharacteristicsintheFildesPeninsulaofKingGeorgeIsland,Antarctica¥ZhaoYeandLiTianjie(I...  相似文献   

4.
(王道德)(陈永亨)ThechemicalcompositionsofAntarcticironmeteoritesandtheirclassification¥WangDaodeandChenYongheng(GuangzhuoInstituteo...  相似文献   

5.
AstudyoncosmicdustparticlesinAntarcticice,snowandnon-AntarcticregionandtheiroriginsWangDaode(王道德)andDaiChengda(戴诚达)(Guangzhou...  相似文献   

6.
束沛镒  张钋 《极地研究》1995,6(1):30-38
Crust-mantlestructureunderSouthPoleandRossSeaBeachinAntarcticaShuPeiyi(束沛镒)andZhangBo(张钋)(InstituteofGeophysics,AcademiaSinic...  相似文献   

7.
ThecharacteristicsofPi2pulsationsatGreatWallStation,AntarcticaYangShaofeng(杨少峰)andXiaoFuhui(肖福辉)(InstituteofGeophysics,Academ...  相似文献   

8.
(杨少峰)(肖福辉)CharacteristicsofPc3pulsationsatGreatWallStation,Antarctica¥YangShaofengandXiaoFuhui(InstituteofGeophysics,Academia...  相似文献   

9.
ThecharacteristicsofgeophysicalfieldandtectonicevolutionintheBransfieldStraitYaoBochu(姚伯初);WangGuangyu(王光宇);ChenBangyan(陈邦彦)a...  相似文献   

10.
仲学锋  王荣 《极地研究》1995,6(1):58-72
ReproductivecharacteristicsofAntarcticKrill,EuphausiasuperbaDana,inthePrydzBayregionZhongXuefeng(仲学锋)andWangRong(王荣)(Institut...  相似文献   

11.
综合分析和研究了采自布兰斯菲尔德海峡主体海槽中PC10孔(753cm长)的全部室内外资料:岩芯、粒度特征、矿物组分、生物尸体群和年代学等,指出了整个岩芯柱代表了区内112.5ka以来冰-海环境的沉积。沉积作用包括生物硅质沉积,火山碎屑沉积和浊流沉积等。其中生物硅质沉积作用,不论在高水位/间冰期或低水位/冰期均占主导地位,不同的是低水位/冰期沉积物中陆源碎屑物含量低且矿物成分和岩屑成分较单一,而高水位/间冰期则相反,且前者沉积速率低于后一时期,这一沉积特点与中低纬度情况有所不同  相似文献   

12.
Biogenic silica contents of sediments on the lower Selenga Delta and Buguldeika saddle in Lake Baikal show distinct fluctuations that reflect changes in diatom productivity, and ultimately, climate. The pattern of the upper 50 m of the section, dating from about 334 ka, is similar to that of the marine oxygen-isotope record, increasingly so as the younger sediments become progressively finer grained and less locally derived with time. The last two interglaciations are marked by biogenic silica abundances similar to those of the Holocene. The equivalent of marine oxygen-isotope stage 3 is distinctly intermediate in character between full glacial and full interglacial biogenic silica values. Following near-zero values during the last glacial maximum, biogenic silica began to increase at about 13 ka. The rise in biogenic silica to Holocene values was interrupted by an abrupt decrease during Younger Dryas time, about 11 to 10 14C ka.  相似文献   

13.
In many areas of Svalbard, the Neoglacial terminal deposits represent the Holocene glacial maximum. The glaciers began the retreat from their Neoglacial maximum positions around 1900 AD. Based on high resolution acoustic data and sediment cores, sedimentation patterns in four tidewater glacier-influenced inlets of the fjord Isfjorden (Tempelfjorden, Billefjorden, Yoldiabukta and Borebukta), Spitsbergen, were investigated. A model for sedimentation of tidewater glaciers in these High Arctic environments is proposed. Glacigenic deposits occur in proximal and distal basins. The proximal basins comprise morainal ridges and hummocky moraines, bounded by terminal moraines marking the maximum Neoglacial ice extent. The distal basins are characterized by debris lobes and draping stratified glacimarine sediments beyond, and to some extent beneath and above, the lobes. The debris lobe in Tempelfjorden is composed of massive clayey silt with scattered clasts. Distal glacimarine sediments comprise stratified clayey silt with low ice-rafted debris (IRD) content. The average sedimentation rate for the glacimarine sediments in Tempelfjorden is 17 mm/yr for the last ca. 130 years. It is suggested that the stratified sediments in Tempelfjorden are glacimarine varves. The high sedimentation rate and low IRD content are explained by input from rivers, in addition to sedimentation from suspension of glacial meltwater. The debris lobes in Borebukta are composed of massive clayey silt with high clast content. Distal glacimarine sediments in Yoldiabukta comprise clayey silt with high IRD content. The average sedimentation rate for these sediments is 0.6 mm/yr for the last 2300 years.  相似文献   

14.
本文利用中国南极科学考察航次获得的沉积物样品,采用分批(batch)实验方法,获取实验室生物硅溶解度,并结合间隙水中可溶性硅剖面,对普里兹湾沉积物中生物硅的溶出过程进行了初步研究。研究结果如下:在25℃,pH 8条件下,普里兹湾IV-10、 IS-4站表层沉积物中生物硅的实验室溶解度分别为1936、1539μmol/dm3,不同层次沉积物溶出结果显示随深度增加溶解度值降低。根据实验室溶解度数据与间隙水硅酸盐Cd的分析比较,表明研究站位沉积物生物硅的早期成岩过程中生物硅的溶出还伴随有其他化学过程。  相似文献   

15.
Samples of glaciomarine sediments and suspended matter from the eastern and central Weddell Sea Shelf were collected during the Norwegian Antarctic Research Expedition (NARE) in 1978/79. Ice-rafted clastic materials are in general the main sediment sources. On the eastern shelf, biogenic materials are abundant (sponges and bryozoan debris). Fine-grained materials, clastic and bioclastic, are additionally supported as fecal aggregates and by currents. The composition of the bottom sediments shows only small variations laterally and within the profiles. Dissolution of the biogenic materials appears to be slight. The suspended matter is dominated by fine silt and clay particles of clastic, biogenic (mainly diatoms) and authigenic (Fe, Mg-rich silicates) origin. Metalliferous particles (Fe, Ti, Zn, Cr, Ni-rich) of possibly anthropogenic and/or cosmic origin are observed. On the upper continental slope and the outer shelf the sedimentation rates are in the range of 2–5 cm/1000 years, which are slightly higher than for the rest of the shelf. The bioclastic glaciomarine deposits grade southward into bioclastic free sediments, showing that glaciomarine deposits outside an ice shelf may form a sequence of alternating bioclastic-rich and bioclastic-free layers. Similarly, late Precambrian carbonate tillite sequences, especially in the case of thin carbonate layers interbedded with tillite layers, may reflect variations in glaciomarine facies rather than interglacial/glacial cycles.  相似文献   

16.
王汝建  肖文申 《极地研究》2009,21(4):255-264
通过北冰洋西部楚科奇海盆M03孔晚第四纪以来生源沉积物,有孔虫丰度和冰筏碎屑(Ice.Rafted Detritus,IRD)的综合研究表明,海洋氧同位素(Marine Isotope Stage,MIS)7期以来,碳酸钙(CaCO )含量和浮游有孔虫丰度在间冰期的增加和冰期的降低,分别指示大西洋水输入的加强和减弱。而有机碳(TOC)和生源蛋白石(Biogenic Opa1)含量的变化可能主要与输入到海底的TOC降解和Opal溶解作用与底层水中的溶解氧有关。间冰期低的TOC和Opal含量可能反映楚
科奇海盆海冰覆盖减少,营养盐供给多,表层生产力增加,通气作用好,底层水富氧,降解和溶解作用增强,保存在沉积物中的TOC和Opal减少;而冰期相对高的TOC和Opal含量可能反映楚科奇海盆海冰覆盖时间较长,营养盐供给少,表层生产力较低,通气作用差,底层水少氧,降解和溶解作用减弱,保存在沉积物中的TOC和Opal增多。  相似文献   

17.
NP93-2柱样采自南极普里兹湾陆架区域,具有明显的冰海沉积作用特征,受冰川和海洋共同作用。粒度参数、矿物组成、微体古生物和地球化学等资料揭示了该区12937a以来的沉积作用特征和沉积环境与气候变动的信息。大约在10ka,气候波动突然明显回暖,冰筏源碎屑物质增加,晚期还有一个短暂气候波动。  相似文献   

18.
通过对独库公路三岔河道班沟等处泥石流扇形地上不同形态的泥石流堆积、冰川堆积和岩屑坡的沉积砾石组构对比研究,发现在不同沉积相中,砾石ab面的组构特点互不相同,都随其不同的沉积动力和地形等沉积条件的差别而有别,所以利用砾石组构这一研究方法,不但可划分不同的沉积相,而且在第四纪地质与沉积学研究中具有重要的意义。  相似文献   

19.
The content and distribution of biogenic silica were investigated in sedi- ment cores from Prydz Bay,Antarctica,during the CHINARE-18/21.cruise.The re- sults show that the content of biogenic silica(BSiO_2) is ranged from 4.89% to 85. 41%,and the average content of biogenic silica is 30.90%,the highest value oc- curred at theⅣ-10 station.The profile of BSiO_2 in sediment is contrast to that of sili- cate in the interstitial water.The content of biogenic silica and organic carbon in the surface sediments in the central area of Prydz Bay gyre were much higher than those in other area,and closely related to the Chla content and primary productivity of phyto- plankton in the surface water column.  相似文献   

20.
During the late Wisconsin, glacial flour from alpine glaciers along the east side of the Cascade Range in southern Oregon was deposited in Upper Klamath Lake. Quantitative interpretation of magnetic properties and grain-size data of cored sediments from Caledonia Marsh on the west side of the lake provides a continuous record of the flux of glacial flour spanning the last 37 000 calendar years. For modeling purposes, the lake sediments from the 13-m core were divided into three sedimentary components defined from magnetic, geochemical, petrographic, and grain-size data. The components are (1) strongly magnetic, glacial flour made up of extremely fine-grained, fresh volcanic rock particles, (2) less magnetic lithic material made up of coarser, weathered volcanic detritus, and (3) non-magnetic biogenic material (largely biogenic silica). Quantitative interpretation is possible because there has been no significant postdepositional destruction or formation of magnetic minerals, nor alteration affecting grain-size distributions. Major steps involved in the interpretation include: (1) computation of biogenic and lithic components; (2) determination of magnetic properties and grain-size distributions of the non-glacial and glacial flour end-members; (3) computation of the contents of weathered and glacial flour components for each sample; (4) development of an age model based on the mass accumulation of the non-glacial lithic component; and (5) use of the age model and glacial flour contents to compute the flux of glacial flour. Comparison of the glacial flour record from Upper Klamath Lake to mapped glacial features suggests a nearly linear relation between flux of glacial flour and the extent of nearby glaciers. At 22 ka, following an extended period during which glaciers of limited size waxed and waned, late Wisconsin (Waban) glaciers began to grow, reaching their maximum extent at 19 ka. Glaciers remained near their maximum extent for 1000 years. During this period, lake sediments were made up of 80% glacial flour. The content of glacial flour decreased as the glaciers receded, and reached undetectable levels by 14 ka.  相似文献   

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