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1.
From central East Greenland, C14 ages between 19,500 > 40,000 years B.P. have been obtained for six samples of marine bivalve shells. The ages seem to be consistent with geological observations and form the basis for a tentative chronology for the Weichselian ice age in the region. It appears that the maximum glaciation during Weichselian times was attained more than 40,000 years ago, and that since then ice-free areas have existed. This assumption agrees with evidence of botanical refugia in the region, and the restricted glacier activity especially during the Upper Pleniglacial (ca. 30,000–15,000 years B.P.) is explained by a reduced supply of moisture. A comparison with evidence from other parts of Greenland indicates that different glacial histories can be expected for different sectors of the Greenland Inland Ice.  相似文献   

2.
Macrofossil plant and insect remains from nearshore marine sediments in Jameson Land, central East Greenland show that the land biotas of the last interglacial stage, the Langelandselv stage, were more diverse than those of the Holocene. Rich dwarf shrub heaths with a diverse assemblage of ericaceous plants occupied low land areas with copses of Betula pubescens on sheltered sites. Many southern extra-limital species were present, and the mean summer temperature was c . 5°C higher than today. The subarctic bioclimatic zone was displaced from southernmost Greenland/Iceland to central East Greenland. The diverse beetle fauna was of palaearctic affinity and strikingly different from the Plio-Pleistocene and the Holocene Greenlandic beetle faunas. A few fossil assemblages from the Hugin Sø Interstade, which is correlated with oxygen isotope stage 5c (early last glacial stage), point to poor, perhaps entirely herbaceous vegetation with a mean summer temperature that was perhaps 3 4°C lower than today.  相似文献   

3.
Schmidt, S., Wagner, B., Heiri, O., Klug, M., Bennike, O. & Melles, M. 2010: Chironomids as indicators of the Holocene climatic and environmental history of two lakes in Northeast Greenland. Boreas, 10.1111/j.1502‐3885.2010.00173.x. ISSN 0300‐9483. Two Holocene sediment sequences from arctic lakes on Store Koldewey, an island in Northeast Greenland, were investigated for fossil chironomid assemblages. A total of 18 and 21 chironomid taxa were identified in 290‐ and 252‐cm‐long sediment sequences from Duck Lake and Hjort Lake, respectively. The chironomid assemblages were very similar in the two lakes. Canonical correspondence analysis (CCA) was used to compare fossil chironomid assemblages from Store Koldewey with chironomid assemblages and environmental conditions presently found in Canadian Arctic lakes and, hence, to infer environmental changes for Northeast Greenland. The first chironomids appeared at c. 9500 cal. a BP in Hjort Lake, and 500 years later in Duck Lake. Taxa typical for cold and nutrient‐poor arctic lakes dominated the earliest assemblages. Chironomid assemblages with taxa typical of higher summer air temperatures and lakes with higher nutrient availability occur between 8000 and 5000 cal. a BP. This period probably marks the regional Holocene thermal maximum, which is relatively late compared with some palaeoenvironmental records from East Greenland. One possible reason could be the location of Store Koldewey at the very outer coast, with local climatic conditions strongly influenced by the cold East Greenland Current. From around 5000 cal. a BP, chironomid assemblages in Duck Lake and Hjort Lake again became more typical of those presently found in Northeast Greenland, indicating relatively cold and nutrient‐poor conditions. This shift coincides with an increase of ice‐rafting debris off East Greenland and an intensification of the East Greenland Current.  相似文献   

4.
Sixteen 40Ar–39Ar ages are presented for alkaline intrusions to appraise prolonged post-breakup magmatism of the central East Greenland rifted margin, the chronology of rift-to-drift transition, and the asymmetry of magmatic activity in the Northeast Atlantic Igneous Province. The alkaline intrusions mainly crop out in tectonic and magmatic lineaments orthogonal to the rifted margin and occur up to 100 km inland. The area south of the Kangerlussuaq Fjord includes at least four tectonic lineaments and the intrusions are confined to three time windows at 56–54 Ma, 50–47 Ma and 37–35 Ma. In the Kangerlussuaq Fjord, which coincides with a major tectonic lineament possibly the failed arm of a triple junction, the alkaline plutons span from 56 to 40 Ma. To the north and within the continental flood basalt succession, alkaline intrusions of the north–south trending Wiedemann Fjord–Kronborg Gletscher lineament range from 52 to 36 Ma.

We show that post-breakup magmatism of the East Greenland rifted margin can be linked to reconfiguration of spreading ridges in the Northeast Atlantic. Northwards propagation of the proto-Kolbeinsey ridge rifted the Jan Mayen micro-continent away from central East Greenland and resulted in protracted rift-to-drift transition. The intrusions of the Wiedemann Fjord–Kronborg Gletscher lineament are interpreted as a failed continental rift system and the intrusions of the Kangerlussuaq Fjord as off-axis magmatism. The post-breakup intrusions south of Kangerlussuaq Fjord occur landward of the Greenland–Iceland Rise and are explained by mantle melting caused first by the crossing of the central East Greenland rifted margin over the axis of the Iceland mantle plume (50–47 Ma) and later by uplift associated with regional plate-tectonic reorganization (37–35 Ma). The Iceland mantle plume was instrumental in causing protracted rift-to-drift transition and post-breakup tholeiitic and alkaline magmatism on the East Greenland rifted margin, and asymmetry in the magmatic history of the conjugate margins of the central Northeast Atlantic.  相似文献   


5.
A glacial chronology for northern East Greenland   总被引：3，自引：1，他引：3  
In East Greenland between 75 and 76N three different glacial episodes can be identified: (1) An early period with more or less total ice cover and in which the ice reached out onto the continental shelf - the Kap Mackenzie stadial; (2) a period with glaciation of intermediate extent, when nunataks and a few ice-free lowland areas existed - the Muschelbjerg stadial; and (3) a final period with glacial advance, when the glaciers were mainly restricted to fjords and larger valleys - the Nanok stadial. Each of these stadials was followed by a period with general deglaciation, from which marine shell-bearing sediments have been found; the Hochstetter Forland interstadial, the Peters Bugt interstadial and the Flandrian interglacial, respectively. The marine limit sank with each of these ice-free periods; probably an isostatic effect of the decreasing amplitude of the glacial advances. The deglaciation after the Nanok stadial began about 9500 B.P. It is not known for certain when this glacial advance started, but 13,000 B.P. or earlier is suggested. According to 14C datings the Peters Bugt interstadial dates from at least 45,000 B.P. and the Hochstetter Forland interstadial from at least 49,000 B.P. However, amino acid analyses indicate a distinct age difference between these two interstadial, and Th/U datings give age estimates of 70,000–115,000 B.P. for the Hochstetter Forland interstadial, which therefore seems to be of Early Weichselian age although a pre-Weichselian age cannot be excluded. The same applies to the preceding Kap Mackenzie stadial. The correspondence between the present glacial chronology and similar tripartite ones on Bafffin Island, Ellesmere Island and Svalbard seems reasonably good  相似文献   

6.
The Weichselian glaciation in Norht lceland is locally divided into three main stages:(1) The maximum stage, when North Iceland was ice-covered northwards to the island of Grimsey; (2) the ice-lake stage, when a series of ice-dammed lakes were formed in Fijóskadalur; and (3) the Langhöll Stadial, 14C age about 10,000 B.P., an advance restricted to the valleys on both sides of Eyjafjördur, after the final emptying of the youngest lake in Fnjöskadalur, By combining changes in strandine gradients with time, an age of about 20,700 B.P. for the oldest ice-dammed lake is predicted. As this a ge is greater than the assumed age, 18,000 B.P., of the maximum extent of the Weichselian glaciation, it is unlikely that the maximum occurred at that time. Possibly, the maximum extent of the Weichselian glaciation in North lceland took place concurrenly with some of the early s tadials that have been identified in Arctic Canada, in East Greenland and on Svalbard.  相似文献   

7.
East Greenland forms one of the least understood of the orogenic belts formed during the amalgamation of Rodinia during late Mesoproterozoic times. Recent U–Pb zircon SHRIMP dating on the widespread Krummedal supracrustal succession and associated granites from central East Greenland has shown that metamorphism and intrusion affected the region at around 0.95–0.92 Ga, approximately 150 m.y. later than the main phase of Grenvillian orogenesis (s.s.). These early Neoproterozoic ages may indicate a link with metamorphism and igneous activity in the Sveconorwegian Belt of Scandinavia rather than true ‘Grenvillian’ events on the eastern margin of Laurentia. Previous plate tectonic reconstructions which link Laurentia and Baltica by a collisional margin extending through central East Greenland at 1.1 Ga were based on early conventional U–Pb zircon dating in central East Greenland, and can no longer be considered viable. Instead, new detrital zircon SHRIMP U–Pb dating studies show that the Krummedal supracrustal succession was deposited between ca. 1.0 Ga and no later than 0.95 Ga, during a time of major sediment deposition widely preserved elsewhere in the North Atlantic region. Erosion associated with post-1.1 Ga collapse of the Grenville–Sunsas orogeny is the most likely source for the majority of the detritus, since the corresponding Baltic margin was dominated by A-type magmatism for much of the period 1.4–1.1 Ga material, which is the age of the bulk of detrital zircons in the Krummedal supracrustal succession. We suggest that the Krummedal supracrustal succession was deposited east or south-east of its present location, and was thrust onto Archaean–Palaeoproterozoic orthogneisses, which in turn were displaced across the parautochthonous foreland during the Caledonian orogeny. The early Neoproterozoic orogenic events recorded in central East Greenland therefore involved the metamorphism of a metasedimentary package of Laurentian–Amazonian affinity during the Sveconorwegian orogeny in the final stages of the collision of Baltica and Laurentia.  相似文献   

8.
Multi-element analyses of more than 600 panned heavy-mineral concentrate samples from the Jameson Land area of central East Greenland were investigated by discriminant analysis which, combined with an a priori knowledge of the geology, was used to assist interpretation and classification the data. The importance of sample density, and the method and degree of sample grouping were investigated. Also the effect of using either the within-covariance or the pooled covariance matrices in the discriminant functions was studied.Discriminant analysis assumes the element concentrations to be normally distributed and that equality of within-covariances exists. These assumptions were not always met, and this was probably the main reason why one-third of the samples could not be classified. However, the study shows that interpretation of the data, although it is historical and forms only part of a regional reconnaissance survey, benefits from the application of discriminant analysis.  相似文献   

9.
Fluvial and deltaic sediments from Jameson Land in East Greenland contain the first record of the leaf beetle Phratora o f. polaris , not presently found in Greenland; the ground beetle Bembidion grapii , north of this species' present northern range limit; and the true bug Nysius gruenlandieus . In addition, there is a rather diverse flora. All of these records are in sediments of Early Holocene age. We suggest that most of these animals and plants immigrated to East Greenland in the Early Holocene by long-distance chance dispersal, mostly from northwest Europe. The environment was physiognomically similar to that of today, but Salix aretica and Cassiope tetragonu that are important dwarf shrubs today had not yet immigrated.  相似文献   

10.
Subfossil bryophyte remains from Jameson Land, central East Greenland reveal diverse moss floras from the Langelandselv interglacial and the Hugin Sø interstadial. Around 30 species are reported as new subfossils from Greenland, indicating our insufficient knowledge of earlier bryophyte floras in the area. Among the species found from the Langelandselv interglacial. Several are southern and do not reach as far north as Jameson Land today, thus indicating a slightly warmer climate than at present in the area. The climate indications for the Hugin Sø interstadial are less clear, and further studies are necessary before delinitivc conclusions can he drawn. A large proportion of the found taxa indicate mineral-rich or intermediately mineral-rich conditions. Several wetland species indicate moving water, and a few sometimes or exclusively ( Sanionia nivalis ) occur in connection with late snow beds or meltwater brooks. Abundant material or the Polytrichaceae and of Racomitrum indicates that more or less unstable soil. with sparse vascular plant cover, was relatively abundant.  相似文献   

11.
The Lilloise is an 8 km4 km layered mafic intrusion which cutsthe plateau basalts of the East Greenland Tertiary province.Lilloise was intruded at 50 Ma, 4–5 Ma after cessationof the voluminous tholeiitic magmatism which accompanied riftingof the East Greenland continental margin. Lilloise is unusualamong layered intrusions in the province because it had a hydrousalkali picrite parent magma and generated a late-stage effluxof magmatic water from the intrusion into the aureole rocks.The three major subdivisions of the layered rocks are: olivine-clinopyroxene,olivine-clinopyroxene-plagioclase and plagioclase-amphibolecumulates. Massive subsidence of the intrusion before completesolidification resulted in deformation of the internal layeringand downturn of the bedding in the surrounding basalts. A strikingfeature of the intrusion is the injection of the layered rocksby a plexus of magmatic sheets which formed at the time of subsidence.The composition of these sheets is representative of the fractionationtrend of the intrusion and ranges from hawaiite to mildly saturatedquartz trachyte. The fractionation trend is successfully explainedby extraction of cumulus minerals of the layered rocks froma parent magma represented by alkali picrite dykes of a contemporaneousregional dyke swarm. Saturated to mildly over-saturated syenitesare a major component of the East Greenland province and theLilloise intrusion is illustrative of an important magmatictrend towards such compositions at this stage in the openingof the North Atlantic. KEY WORDS: Lilloise intrusion; East Greenland; alkali picrite magma; layered intrusion; magmatic differentiation *Corraponding author  相似文献   

12.
Greenland is the largest island on Earth, with 80% of its area covered by a thick ice sheet. The coastal areas are underlain by variable rocks ranging from Eoarchean to the most recent ages. Greenland has a mineral exploration tradition since its colonization in the 18th century, and mining of cryolite started in 1854. Since the 1960s, the country is explored systematically for various commodities, which however resulted only in limited mining activity in only a few successful mines. Most exploration has been based on prospecting followed by exploration around the exposed mineralization.The geology from North-West Greenland along the coast to the south and along the eastern coast north to Kangerlussuaq Fjord is dominated by deeply eroded Archean and Paleoproterozoic rocks. The metallogeny is largely controlled by mid crustal processes and the preservation potential of mineralization in the deeper crust. Significant mineralization is found in orthomagmatic Ni-PGE-Au sulfide and Cr- or Fe-Ti-V oxide systems and hypozonal orogenic gold systems in major shear zones. Interestingly, the ultramafic units of the orthomagmatic systems locally host gemstone-quality corundum mineralization. Graphite mineralization occurs in amphibolite-granulite facies metasedimentary units and in shear zones in Paleoproterozoic orogens. Mesozonal orogenic gold and iron ore in banded iron formation are restricted to localized lower metamorphic grade areas along the west coast. Larger units of preserved Paleoproterozoic metasedimentary and metavolcanic rocks are restricted to South, central East and central West Greenland, where base metal mineralization formed the significant Zn-Pb Black Angel deposit.Widespread sedimentation and localized mafic magmatism started in the late Paleoproterozoic in various continental to shallow marine basins and lasted with interruptions until the start of the Caledonian Orogeny. These late Paleoproterozoic to early Paleozoic sedimentary rocks are variably deformed and metamorphosed by subsequent orogeny and mainly preserved in northern and eastern Greenland. They host stratiform sedimentary base metal mineralization of only limited known extent, except the sedimentary exhalative Zn-Pb Citronen deposit in central North Greenland. The Caledonian and subsequently the Ellesmerian orogens affected the eastern and northern Laurentian margin, respectively. Mineral systems of only limited known extent related to this orogeny are Mississippi Valley Type Zn-Pb in the Ellesmerian foreland, mesozonal orogenic gold in Caledonian shear zones and magmatic-hydrothermal W-Sb ± Au ± Cu systems in and adjacent to Caledonian granites. Renewed and almost continuous sedimentation occurred from the Devonian until Paleogene in eastern Greenlandic basins. The sedimentary units host stratiform sedimentary base metal mineralization of only small known magnitude. The Paleogene in eastern and central West Greenland is characterized by widespread mafic-ultramafic magmatism, forming flood basalt and a series of intrusions in East Greenland. Nickel-sulfide mineralization is locally hosted by the mafic-ultramafic rocks in central West Greenland, whereas eastern Greenlandic mafic and felsic intrusions host significant orthomagmatic PGE-Au mineralization in Skaergaard, and magmatic hydrothermal Mo-Au-Ag mineralization in Malmbjerg and Flammefjeld.Western and southern Greenland was a relative stable shield from Paleoproterozoic times and is intruded by localized Meso- and Neoproterozoic alkaline and carbonatite suites, which form part of a larger Mesoproterozoic rift only in South Greenland. These intrusions host locally significant REE-Nb-Ta-U-Zn-Be in Kvanefjeld, Kringlerne and Motzfeldt deposits of South Greenland and the southern West Greenlandic Sarfartoq deposit. Diamond mineralization is spatially associated with the alkaline and carbonatite intrusions in southern West Greenland.The long and complex geological evolution recorded in Greenland appears to be in contrast with only few examples of successful mineral exploration and mining. Numerous mineral deposits are developed in neighboring Arctic countries, making the remote Arctic setting an unlikely single argument for the situation. Geological knowledge is still relatively basic for many parts of Greenland and modern geophysical and geochemical data is often only available at a regional scale, which makes knowledge- and mineral system-driven exploration difficult and costly. The review of the Greenlandic metallogeny in this paper, however, clearly shows the enormous potential for finding ores in a wide variety of settings.  相似文献   

13.
Wagner, B., Bennike, O., Cremer, H. & Klug, M. 2010: Late Quaternary history of the Kap Mackenzie area, northeast Greenland. Boreas, Vol. 39, pp. 492–504. 10.1111/j.1502‐3885.2010.00148.x. ISSN 0300‐9483. The Kap Mackenzie area on the outer coast of northeast Greenland was glaciated during the last glacial stage, and pre‐Holocene shell material was brought to the area. Dating of marine shells indicates that deglaciation occurred in the earliest Holocene, before 10 800 cal. a BP. The marine limit is around 53 m a.s.l. In the wake of the deglaciation, a glaciomarine fauna characterized the area, but after c. one millennium a more species‐rich marine fauna took over. This fauna included Mytilus edulis and Mysella sovaliki, which do not live in the region at present; the latter is new to the Holocene fauna of northeast Greenland. The oldest M. edulis sample is dated to c. 9500 cal. a BP, which is the earliest date for the species from the region and indicates that the Holocene thermal maximum began earlier in the region than previously documented. This is supported by driftwood dated to c. 9650 cal. a BP, which is the earliest driftwood date so far from northeastern Greenland and implies that the coastal area was at least partly free of sea ice in summer. As indicated by former studies, the Storegga tsunami hit the Kap Mackenzie area at c. 8100 cal. a BP. Loon Lake, at 18 m a.s.l., was isolated from the sea at c. 6200 cal. a BP, which is distinctly later than expected from existing relative sea‐level curves for the region.  相似文献   

14.
ABSTRACT Palaeoceanographic reconstructions from the North Atlantic indicate massive ice breakouts from East Greenland near the onset of cold Dansgaard–Oeschger (D–O) stadials. In contrast to these coolings in the North Atlantic area, a new sea-surface temperature record reveals concomitant warm spells in the northern North Pacific. A sensitivity experiment with an atmospheric general circulation model is used to test the potential impact of sea-surface warmings by 3.5 °C in the North Pacific, on top of otherwise cold stadial climate conditions, on the precipitation regime over the Northern Hemisphere ice sheets. The model predicts a maximum response over East Greenland and the Greenland Sea, where a 40% increase in net annual snow accumulation occurs. This remote effect of North Pacific warm spells on the East Greenland snow-accumulation rate may play an important role in generating D–O cycles by rebuilding the ice lost during ice breakouts. In addition, the increased precipitation over the Greenland Sea may help to sustain the D–O stadial climate state.  相似文献   

15.
Uranium-series dating of oxygen and carbon isotope records for stalagmite SJ3 collected in Songjia Cave, central China, shows significant variation in past climate and environment during the period 20-10 ka. Stalagmite SJ3 is located more than 1000 km inland of the coastal Hulu Cave in East China and more than 700 km north of the Dongge Cave in Southwest China and, despite minor differences, displays a clear first-order similarity with the Hulu and Dongge records. The coldest climatic phase since the Last Glacial Maximum, which is associated with the Heinrich Event 1 in the North Atlantic region, was clearly recorded in SJ3 between 17.6 and 14.5 ka, in good agreement in timing, duration and extent with the records from Hulu and Dongge caves and the Greenland ice core. The results indicate that there have been synchronous and significant climatic changes across monsoonal China and strong teleconnections between the North Atlantic and East Asia regions during the period 20-10 ka. This is much different from the Holocene Optimum which shows a time shift of more than several thousands years from southeast coastal to inland China. It is likely that temperature change at northern high latitudes during glacial periods exerts stronger influence on the Asian summer monsoon relative to insolation and appears to be capable of perturbing large-scale atmospheric/oceanic circulation patterns in the Northern Hemisphere and thus monsoonal rainfall and paleovegetation in East Asia. Climatic signals in the North Atlantic region propagate rapidly to East Asia during glacial periods by influencing the winter land-sea temperature contrast in the East Asian monsoon region.  相似文献   

16.
Modifications to the upper Bathonian zonal scale for northern East Siberia provided by the newly available paleontological record on Middle Jurassic reference sections in the Arctic regions of Yakutia and by the revised earlier collections, are justified. The oldest East Siberian members of Cadoceras are found to be characteristic not of the initial Callovian age as believed by Russian paleontologists, but of the terminal Bathonian age as was previously shown in the biostratigraphic scheme of East Greenland. The succession of zones and index species analogous to that of the latter is revealed in the studied region and the zonal boundaries in Siberia and East Greenland are inferred to be synchronous. Finds of Cadoceras calyx in the upper Bathonian scale permitted, for the first time, the recognition of a corresponding zone. The Bathonian-Callovian boundary is placed between the calyx and anabarense zones. The upper Bathonian zonal scale of northern East Siberia is now in total agreement with the East Greenland zonal scale.  相似文献   

17.
On the basis of field and laboratory studies supported by thermoluminescence dates, an occurrence of marine and glacial sediments is described from South Spitsbergen. These deposits are thought to date from the Holsteinian interglacial and the Saalian glacial stages respectively. In addition, the evidence and extent of Vistulian and Holoccne glacial advances in South Spitsbergen are presented. These advances occurred at 50,000–43,000, 30,000–10,000, 3,000–2,500 and 600–100 years B.P. The latter have been tentatively correlated with those recorded in other parts of Svalbard, as well as in East Greenland, the Barents Sea, Scandinavia, the Baltic Sea, North Poland and the Russian Plain.  相似文献   

18.
 In the nunataks of the Prince of Wales Mountains the tholeiite flood basalts of the East Greenland Tertiary Province are unconformably overlain by alkaline lavas. The majority of the alkaline lavas are strongly porphyritic picrites, ankaramites and hawaiites. These rocks have lower 143Nd/144Nd and higher 87Sr/86Sr than the tholeiitic flood basalts and are isotopically akin to ocean island basalts. The alkaline lavas also have high concentrations of incompatible elements which on normalised plots have a pattern which is similar in shape to that of enriched oceanic island basalts. The isotopic and chemical characteristics of these late-stage representatives of the East Greenland volcanic activity are attributed to their derivation from the peripheral regions of the East Greenland plume, the axial region of which was moving progressively eastwards relative to the westwards drift of the Greenland plate. It is proposed that the incompatible element contents of the magmas so produced were dominated by small degree melts formed beneath a cap of continental lithosphere in the marginal regions of the plume. Received: 5 June 1995 / Accepted: 11 December 1995  相似文献   

19.
The sedimentary record from the Ugleelv Valley on central Jameson Land, East Greenland, adds new information about terrestrial palaeoenvironments and glaciations to the glacial history of the Scoresby Sund fjord area. A western extension of a coastal ice cap on Liverpool Land reached eastern Jameson Land during the early Scoresby Sund glaciation (≈the Saalian). During the following glacial maximum the Greenland Ice Sheet inundated the Jameson Land plateau from the west. The Weichselian also starts with an early phase of glacial advance from the Liverpool Land ice cap, while polar desert and ice‐free conditions characterised the subsequent part of the Weichselian on the Jameson Land plateau. The two glaciation cycles show a repeated pattern of interaction between the Greenland Ice Sheet in the west and an ice cap on Liverpool Land in the east. Each cycle starts with extensive glacier growth in the coastal mountains followed by a decline of the coastal glaciation, a change to cold and arid climate and a late stage of maximum extent of the Greenland Ice Sheet. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

20.
A high-resolution diatom record from core MD99-2275 shows a general paleoceanographic change in the northern North Atlantic since 5000 cal. a B.P. by Principle Component Analysis. Sea surface temperature (SST) increased gradually during 5000 and 3000 cal. a B.P. on the North Icelandic shelf as a result of increasing influence of warm Atlantic water mass from the Irminger Current. It apparently started to decrease since 3000 cal. a B.P. due to the weakening influence of warm water and enhanced influence of the Polar and Arctic water masses from the East Greenland Current and the East Icelandic Current. Abrupt decreases in SST and intrusions of Polar and Arctic water superimposed on the late Holocene cooling trend during 3000-2600, 1300-1000 and 600-200 cal. a B.P.. The paleoceanographic record revealed from core MD99-2275 corresponds well with δ18O record from the GISP2 and is generally consistent with other SST records based on diatom on the North Icelandic shelf. __________ Translated from Marine Science Bulletin, 2008, 27(5) [译自:海洋通报]  相似文献   

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