2 resultados para Lower (upper) Semicontinuous Multivalued Mapping

em Institutional Repository of Leibniz University Hannover


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The belemnite species Hibolites jaculoides Swinnerton, 1937 is redefined on the basis of a bed by bed collection of 2100 rostrums from the Upper Hauterivian (Cretaceous deposits of NW Germany and Yorkshire, England. According to the variate-statistical evaluation of the data gathered, definite phylotic changes are disdernible within the species. All characters measured indicate a definite tendency towards reduction in size. Large-sized, club-shaped specimens are typical for the stratigraphically older beds, delicate and slender-built forms dominate in the upper Upper Hauterivian. Comparison of the material from England and Germany yielded that three of the varieties described by Swinnerton are limited mainly to the lower Upper Hauterivian of England.

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The Late Glacial and Holocene landscape development in the vicinity of the River Elbe near Neuhaus, Lower Saxony, was studied during geological mapping of the area. The geological and geobotanical methods used in these investigations were chosen to cope with the difficulties which arise during research on Quaternary flood plains in low country. Paleochannel fill and areas of flood-plain sediments were drilled, the lithology examined, and the sediments dated on the basis of their pollen content. No evidence was found for the existence before the Middle Ages of paleo- channels the size of the present River Elbe. Before the first measures were made to regulate the Elbe River, it was an anastomosing river system with numerous small branches. The lower parts of the flood-plain profiles are predominantly sand and the upper parts silty-clayey loam. With the construction of effective levees over the last several centuries, the flow velocity of the Elbe has increased considerably during high water periods and instead of the deposition of meadow loam, sand was deposited as natural levees. The main belt of sand dunes on the east bank of the Elbe overlies Preboreal to Boreal lake mud and is, therefore, of Holocene age.