The Quaternary of the Kattegat area, Scandinavia: a review   总被引：1，自引：0，他引：1  

HOLGER LYKKE-ANDERSEN  KAREN LUISE KNUDSEN  CHRISTIAN CHRISTIANSEN 《Boreas: An International Journal of Quaternary Research》1993,22(4):269-281

The Quaternary sedimentary history and its relations to the pre-Quaternary in the Kattegat region are reviewed. The Quaternary in the area is restricted to relatively young sediments, including scattered findings of Saalian deposits and more continuous occurrences from the Eemian, the Weichselian and the Holocene. Glacial and interglacial palaeoenvironmental reconstructions, including Holocene changes in oceanographic circulation, are reviewed, and the recent sedimentary processes and the present hydrographic regime are outlined. Furthermore, Quaternary and present tectonic activity in connection with some of the pre-Quaternary fault zones is discussed.  相似文献   

Dynamics of the last glaciation in eastern Svalbard as inferred from glacier-movement indicators     

OTTO SALVIGSEN  LENA ADRIELSSON  CHRISTIAN HJORT  MICHAEL KELLY  JON Y. LANDVIK  LARS RONNERT 《Polar research》1995,14(2):141-152

Glacial striae and other ice movement indicators such as roche moutonées, glacial erratics, till fabric and glaciotectonic deformation have been used to reconstruct the Late Weichselian ice movements in the region of eastern Svalbard and the northern Barents Sea. The ice movement pattern may be divided into three main phases: (1) a maximum phase when ice flowed out of a centre east or southeast of Kong Karls Land. At this time the southern part of Spitsbergen was overrun by glacial ice from the Barents Sea; (2) the phase of deglaciation of the Barents Sea Ice Sheet, when an ice cap was centred between Kong Karls Land and Nordaustlandet. At the same time ice flowed southwards along Storfjorden; and (3) the last phase of the Late Weichselian glaciation in eastern Svalbard is represented by local ice caps on Spitsbergen, Nordaustlandet, Barentsoya and Edgeøya.
The reconstructed ice flow pattern during maximum glaciation is compatible with a centre of uplift in the northern Barents Sea as shown by isobase reconstructions and suggested by isostatic modelling.  相似文献   

Petrogenesis of Mafic to Felsic Plutonic Rock Associations: the Calc-alkaline Querigut Complex, French Pyrenees   总被引：1，自引：0，他引：1  

ROBERTS  MALCOLM P.; PIN  CHRISTIAN; CLEMENS  JOHN D.; PAQUETTE  JEAN-LOUIS 《Journal of Petrology》2000,41(6):809-844

The Quérigut mafic–felsic rock association comprisestwo main magma series. The first is felsic comprising a granodiorite–tonalite,a monzogranite and a biotite granite. The second is intermediateto ultramafic, forming small diorite and gabbro intrusions associatedwith hornblendites and olivine hornblendites. A U–Pb zirconage of 307 ± 2 Ma was obtained from the granodiorite–tonalites.Contact metamorphic minerals in the thermal aureole providea maximum emplacement pressure of between 260 and 270 MPa. Petrographiccharacteristics of the mafic and ultramafic rocks suggest crystallizationat <300 MPa, demonstrating that mantle-derived magmas ascendedto shallow levels in the Pyrenean crust during Variscan times.The ultramafic rocks are the most isotopically primitive components,with textural and geochemical features of cumulates from hydrousbasaltic magmas. None of the mafic to ultramafic rocks havedepleted mantle isotope signatures, indicating crustal contaminationor derivation from enriched mantle. Origins for the dioritesinclude accumulation from granodiorite–tonalite magma,derivatives from mafic magmas, or hybrids. The granitic rockswere formed from broadly Proterozoic meta-igneous crustal protoliths.The isotopic signatures, mineralogy and geochemistry of thegranodiorite–tonalites and monzogranites suggest crystallizationfrom different magmas with similar time-integrated Rb/Sr andSm/Nd isotope ratios, or that the granodiorite–tonalitesare cumulates from a granodioritic to monzogranitic parent.The biotite granite differs from the other felsic rocks, representinga separate magma batch. Ages for Quérigut and other Pyreneangranitoids show that post-collisional wrenching in this partof the Variscides was under way by 310 Ma. KEY WORDS: Variscan orogeny; Pyrenees; Quérigut complex; epizonal magmatism; post-thickening; mafic–felsic association  相似文献   

Morphology and facies architecture of a falling sea level strandplain, Umiujaq, Hudson Bay, Canada   总被引：1，自引：0，他引：1  

CHRISTIAN FRASER  PHILIP R. HILL  MICHEL ALLARD† 《Sedimentology》2005,52(1):141-160

Coastal strandplain deposits near Umiujaq, eastern Hudson Bay, Canada, were formed under falling relative sea level conditions resulting from postglacial isostatic uplift. Ground-probing radar profiles across the strandplain reveal a lower progradational unit (LPU) discordantly overlain by an upper progradational unit (UPU), which were correlated with stratigraphic sections exposed in incised valley walls. The discordance is a wave erosion surface (WES) that separates fine shoreface sands of the LPU from coarse-sand and gravel of the UPU. Major basal downlap surfaces can be traced updip into marine terraces and define downstepping wedges. The downstepping is interpreted as representing ‘autocyclic’ morphological reconfiguration rather than a response to changes in the rate of sea level fall. The internal architecture is strongly dependent on the accommodation and thus on antecedent topography. A conceptual model for strandplain deposition under falling sea level incorporates a bipartite shallowing-upward sandy succession when sufficient accommodation is available. Where accommodation space is limited, a sharp-based bar-and-beach sandbody directly overlies muddy deeper water deposits and the WES resembles a regressive surface of erosion.  相似文献   

Palaeoenvironments and changes in relative sea level during the last interglaciation at Langelandselv, Jameson Land, East Greenland     

HENRIK VOSGERAU  SVEND FUNDER  MICHAEL KELLY  KAREN LUISE KNUDSEN  CHRISTIAN KRONBORG  HANNE BIRGIT MADSEN  HANS PETTEK SEJRUP 《Boreas: An International Journal of Quaternary Research》1994,23(4):398-411

Coastal cliffs and stream cut sections at Langelandselv on Jameson Land show a 22 m thick sedimentary succession reflecting the development of shallow marine and fluvial environments during the last interglaciation. The shallow marine sediments were deposited in upper shoreface, back-barrier, and delta environments during a rise in the relative sea level from 0 to 18 m. The interglacial succession ends with glaciotectonically dislocated fluvial sand, and is capped by alternating beds of lodgement till and fluvial sand, deposited during the Early Weichselian. The age is determined by palacoceanographic correlation of molluse and foraminifer faunas with isotopic substage 5e in the deep sea record, supported by luminescencs and U/Th dates and amino acid analysis.  相似文献   

The beetles of Greenland - and how they might have got there     

CHRISTIAN HJORT 《Boreas: An International Journal of Quaternary Research》1989,18(3):244-244

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