摘要:

In the raised bog Draved Mose, rates of peat formation and degrees of humification were determined in two peat sections. Based on 59 calibrated C‐14 dates, accumulation rates during the last 6500 years of 0.16 to 0.80 mm/year were found. The peat layers were analyscd forSphagnumspecies, rhizopods, and pollen and spores. A clear relation between humification degrees and humidity at the time of formation was found, while the relation between measured growth rates and degrees of humification varied throughout the 2.5 m thick peat section. These variations are thought to be mostly a result of autocompactio

ISSN:0300-9483    

DOI:10.1111/j.1502-3885.1975.tb00675.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

Thermokarst features occur widely in the younger ice‐cored moraines and kame terraces in the Dry Valleys region of Victoria Land, Antarctica Common forms are melt dolines, caves, natural bridges, and subsurface. flow. Such features typically develop in stagnant glacial ice with a low material exchange.The development of a thermokarst cave system near the Taylor Glacier during the southern summer of 1973–74 is described, and the role of the thermokarst process in land‐form development in the Dry Valleys area is disc

ISSN:0300-9483    

DOI:10.1111/j.1502-3885.1975.tb00676.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

Shells were collected from marine sediments in the area youth of Disko Bugt from various altitudes up to 50 m. Radiocarbon dates showed that only some of the shells were from sands and gravels formed at or near sea level and could be used to date the land/sea level changes. The shell dates show a regression from about 43 m at 7000 B.P. to about 8 m at 4000 B.P. All sediments with shells are Holocene in age, the oldest date being nearly 9000 B.P. The date of the Fjord Stage moraine in Orpigsoq is estimated at about 8000 B.P. on the basis of the altitude of the marine limit at 62 m. Extrapolations dated the older marine limits, falling from an altitude of 130 m to 80 m, at about 11,000 B.P. to 9000 B.P. These are approximate dates for the deglaciation of the area outside the Fjord Stage moraine. The distribution of shells in the sediments was shown to be largely dependent on habitat and water depth. At least some changes ill fauna were caused by a decrease of water depth due to the relative uplift of land. No tilting or warping of the land surface could he detected in the at‐ea about 100 km long from the coast towards the Inland Ic

ISSN:0300-9483    

DOI:10.1111/j.1502-3885.1975.tb00677.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

The revision by Järnefors (1973) of the Swedish Time Scale, bascd on vnrve chronology, is criticized as regards the connection between the Sundsvall and Bollnäs‐Söderhamn regions. A numbcr of facts briefly reviewed in the article indicate that the ice iecession proceeded in a more northerly direction than according to Järnefors. The absence of connection, a different direction of ice recession, and the possible error found by Fromm (1970) could together produce an error in the time scale which in southern Sweden may exceed 1000

ISSN:0300-9483    

DOI:10.1111/j.1502-3885.1975.tb00678.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

Contributions have been made to the theory of the relation between terrestrial magnetism and glaciations. The results are applied to the ice sheets of high‐latitude regions. A review of Pleistocene palcomagnetic dating is give

ISSN:0300-9483    

DOI:10.1111/j.1502-3885.1975.tb00679.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY