A tungsten vein deposit in Bolivia     

PETER THORN 《Geology Today》1988,4(5):176-178

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Involutions in the Middle Pleistocene (Anglian) Barham Soil, eastern England: a comparison with thermokarst involutions from arctic Canada     

JULIAN B. MURTON  COLIN A. WHITEMAN  PETER ALLEN 《Boreas: An International Journal of Quaternary Research》1995,24(3):269-280

Involutions in the early Anglian Barham Soil at Newney Green, Essex, and Badwell Ash, Suffolk, in eastern England, are attributed to soft-sediment deformation during an episode of regional thermokarst development. The involutions show a striking resemblance in morphology and size to thermokarst involutions within a palaeo-thaw layer at Crumbling Point, western arctic Canada. By analogy with the thermokarst involutions, the involutions in the Barham Soil are reinterpreted to have formed by loading during the melting of an ice-rich layer at the top of Anglian permafrost. This period of thermokarst development may have coincided with an episode of intra-Anglian climatic amelioration. Reinterpretation of the Barham Soil involutions implies that many other Pleistocene involutions in Britain may have formed during periods of thermokarst development rather than by active-layer cryoturbation.  相似文献   

The effects on oceanic planetary waves of coupling with an atmospheric energy balance model     

RICCARDO FARNETI  PETER D. KILLWORTH 《地球，A辑:动力气象学与海洋学》2005,57(5):742-757

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Quantification of carbon dioxide, methane, nitrous oxide and chloroform emissions over Ireland from atmospheric observations at Mace Head     

SÉBASTIEN BIRAUD  PHILIPPE CIAIS  MICHEL RAMONET  PETER SIMMONDS  VICTOR KAZAN  PATRICK MONFRAY  SIMON O'DOHERTY  GERARD SPAIN  S. GERRARD JENNINGS 《Tellus. Series B, Chemical and physical meteorology》2002,54(1):41-60

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Holocene temporal and spatial variation in the radiocarbon reservoir age of three Danish fjords     

JESPER OLSEN  PETER RASMUSSEN  JAN HEINEMEIER 《Boreas: An International Journal of Quaternary Research》2009,38(3):458-470

Holocene temporal and spatial reservoir age variations have been investigated in three Danish fjords (Horsens Fjord, Tempelkrog in Isefjord and Skælskør Nor) by ¹⁴C dating paired samples of terrestrial plant material and marine molluscs in sediment cores. The local reservoir age offsets at all three sites show significant temporal and local variations, with ΔR(t) values ranging from −425 to 620 yr. The ΔR(t) values for Horsens Fjord range from −425 to 0 yr, for Tempelkrog from −230 to 360 yr and for Skælskør Nor from 30 to 620 yr. The differences are best explained by differences in local hydrographic configuration, catchment characteristics and connection with the inner Danish seas. The observed temporal ΔR(t) variations are not synchronous, which is probably due to the overriding role played by numerous local factors affecting the ΔR(t) values. Based on the reservoir data from Horsens Fjord and Tempelkrog, it is suggested as a working hypothesis that the ΔR value for Kattegat prior to 4500 cal. yr BP was negative, i.e. between −130 and −200 yr. The temporal and local variations in the reservoir age underline the problems and uncertainties connected with radiocarbon-dating fossil human skeletons with marine diets. Overall, our data show that reservoir ages in Danish fjords and estuaries are both site-specific and time-specific, implying that modern reservoir ages cannot simply be applied back in time. This conclusion may also be valid in the case of fjords and estuaries in large parts of the Baltic too.  相似文献   

Geology and palynology of the Triassic succession of Bjørnøya     

ATLE MØRK  JORUNN OS VIGRAN  PETER A. HOCHULI 《Polar research》1990,8(2):141-163

The Triassic succession of Bjørnøya (200 m) comprises the Lower Triassic Urd Formation (65 m) of the Sassendalen Group, and the Middle and Upper Triassic Skuld Formation (135 m) of the Kapp Toscana Group. These units are separated by a condensed '.'Middle Triassic sequence represented by a phosphatic remainé conglomerate (0.2m).
The Urd Formation consists of grey to dark grey shales with yellow weathering dolomitic beds and nodules. Palynology indicates the oldest beds to be Diencrian; ammonoid faunas in the middle and upper part of the formation arc of Smithian age. The organic content (c. 1 %) includes kerogen of land and marine origin, reflecting a shallow marine depositional environment.
The Skuld Formation is dominated by grey shales with red weathering siderite nodules. There are minor coarsening upwards sequences; the highest bed exposed is a 20 m thick, very fine-grained sandstone. Palynomorphs indicate a late Ladinian age for the lower part of the formation, and macrofossils and palynomorphs indicate Ladinian to Carnian ages for the upper part. Sedimentary structures, a sparse marine fauna and microplankton indicate deposition in a shallow marine environment. The organic residues contain dominantly terrestrially derived kerogen.  相似文献   

The western Baltic sea ice season in terms of a mass-related severity index: 1879–1992     

GERHARD KOSLOWSKI  PETER LOEWE 《地球，A辑:动力气象学与海洋学》1994,46(1):66-74

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EASTERN EUROPE     

PETER PERRY 《New Zealand geographer》1990,46(1):56-56

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Interglacial Chironomidae (Diptera) from Thule, Northwest Greenland: matching modern analogues to fossil assemblages     

KLAUS PETER BRODERSEN  OLE BENNIKE 《Boreas: An International Journal of Quaternary Research》2003,32(4):560-565

An analysis of subfossil insect remains (Diptera, Chironomidae) from an interglacial site at Narsaarsuk near Thule Air Base, NW Greenland, was undertaken to complement our understanding of last interglacial environments in the Arctic by analogue matching to modern chironomid assemblages. The subfossil larval midge head capsules were well preserved and 82% of the chironomid remains were identified as eight different extant chironomid taxa. The assemblage was dominated by the lotic Diamesa (43.8%), a number of lentic taxa (Hydrobaenus, Psectrocladius, Cricotopus/Orthocladius) and a few semi-aquatic taxa (Smittia, Chaetocladius). A single black fly head capsule (Diptera, Simuliidae) was registered. The interglacial sample was compared to subfossil chironomid assemblages from 42 lakes in West Greenland, two glacier lakes (with and without river influence) and a quantitative zoobenthos study from Narsaq Elv. Similarity analysis, analogue matching and multidimensional scaling suggest a lotic, cold, glacier-fed interglacial palaeo-biotope. Quantitative temperature reconstruction was not possible owing to a high dissimilarity to modern lentic chironomid assemblages from West Greenland. However, the simple numerical methods convincingly managed to reflect an interglacial river and stream environment, which can be difficult to document from other palaeoecological data.  相似文献   

Trichoptera remains from early Holocene river deposits in the Great Belt, Denmark     

PETER WIBERG-LARSEN  OLE BENNIKE  JØRN BO JENSEN  WOLFRAM LEMKE 《Boreas: An International Journal of Quaternary Research》2001,30(4):299-306

Analyses of a sediment core from the Great Belt documented the local presence of fluvial deposits. The sediments consisted of silt, clay, sand and organic detritus and they contained macroscopical remains of a mixture of terrestrial, telmatic, lacustrine and fluvial plants and animals. Most noteworthy was the abundance of remains of caddisfly larvae, totalling at least 24 species, which were dominated by fluvial species. Thus, filter-feeding hydropsychids made up approximately 95% out of 1496 identified specimens, the dominating species being Hydropsyche contubernalis and H. pellucidula . The present-day requirements of the recorded species point to a fairly fast-flowing river, at least locally, with areas of stones (some with moss growth) and gravel, but also to more slowly-flowing parts with sand, fine and coarse detritus. This river may have been considerably larger than any present-day Danish river. It appears that the fluvial deposits formed locally in connection with flooding of the area south of the core position. AMS radiocarbon dating shows that the sequence was deposited very rapidly during the early Holocene, about 10650 to 10250 cal. years BP. The occurrence of the lentic Leptocerus tineiformis points to a climate at least as warm as today.  相似文献