Active ice-sheet deglaciation and ice-dammed lakes in the northern Cairngorm Mountains, Scotland   总被引：1，自引：0，他引：1  

VANESSA BRAZIER  MARTIN P. KIRKBRIDE  JOHN E. GORDON 《Boreas: An International Journal of Quaternary Research》1998,27(4):297-310

Mapping of ice-marginal and glaciolacustrine deposits in the northern Cairngorm Mountains allows the nature of deglaciation following the Last Glacial Maximum (c.18 000 BP) to be reinterpreted. Two ice-dammed lakes were ponded between the Glenmore lobe of the Scottish ice sheet and local glaciers draining northwards from the Cairngorm Mountains. Delta progradation from the southern end of each lake reflects dominant meltwater sources and glacio-hydrological gradients. Sediment facies representing subaqueous mass-flow deposits, lakebottom rhythmites, lower and upper foresets and topsets are associated with prograding delta fronts. Moraines show that the lakes were ice dammed at both ends, evidence that active glaciers existed in the Cairngorm Mountains while ice was retreating from Strath Spey, and that deglaciation was punctuated by readvances of the ice margin. These results indicate that an ice-stagnation model of deglaciation is invalid for most of the duration of ice wastage, but instead support an active-retreat hypothesis with multiple, climatically forced readvances.  相似文献   

PERI‐URBAN AGROFORESTRY IN THE BRAZILIAN AMAZON*     

VANESSA A. V. SLINGER 《Geographical review》2000,90(2):177-190

ABSTRACT. Together, urbanization and the search for sustainable development present a dilemma in the Brazilian Amazon: how to accommodate an expanding urban population while creating and maintaining sustainable production systems that feed the people and manage the forest. A unique peri‐urban agroforestry project, implemented by a municipal government in western Amazonia and concerned with a citywide influx of rural agriculturalists and former forest‐dwelling extractive producers, is examined as a source of food and self‐determination. Peri‐urban agroforestry seems to be a viable option for other Amazonian cities that are experiencing increasing urbanization and its associated problems.  相似文献