منابع مشابه
Emergent drumlins and their clones: from till dilatancy to flow instabilities
Subglacial bedforms are a range of landforms (10–10m long) shaped mostly in glacial sediments and are abundant on ice-sheet beds. Numerous explanations for their generation, especially of drumlins, have been proposed. Rather than viewing them as resulting from erosion or deposition directly by ice, Smalley and Unwin (1968) proposed that both might occur simultaneously if, beneath the glacier, a...
متن کاملOn the size and shape of drumlins
We provide a mechanistic explanation for observed metrics for drumlins, which represent their sizes and shapes. Our explanation is based on a concept of drumlin growth occurring through a process of instability, whereby small amplitude wave forms first grow as ice slides over a bed of deformable sediments, following by a coarsening process, in which the wavelength as well as the relief of the d...
متن کاملEvolution equations for dunes and drumlins
Dunes and drumlins are examples of bedforms, geomorphological patterns in which the surface of the Earth is shaped by the erosive power of wind, water or ice. Aeolian dunes (i.e., desert dunes) are the most familiar such feature. Coastal sand dunes are a feature of common experience, and we are also familiar with the existence of dunes in deserts. Dunes are formed by the erosive power of the wi...
متن کاملGeochemical Partitioning in Till
and Vagners (1971, 1972) expressed this phenomenon elegantly by introducing the concept of "terminal mode" for the optimum grain size to which a mineral can be reduced, given the force and energy typically available in the glacial environment. Thus, hard, uncleaved or poorly cleaved minerals such as quartz, fcldspar, garnet, pyrite and magnetite dominate either the medium or the fine sand fract...
متن کاملMORPHOLOGY OF DRUMLINS: A COMPARATIVE ANALYSIS OF SELECTED DRUMLIN FIELDS IN NORTH AMERICA Morphology of Drumlins: A Comparative Analysis of Selected Drumlin Fields in North America
Pleistocene glaciers revealed numerous types of land formations in their retreat northward during climatic warming. The postglacial landscape contains various features, such as moraines, flutes, and drumlin fields. Drumlin fields in southeastern Wisconsin and west central New York are compared in terms of drumlin morphology to ascertain regional differences between drumlin fields formed by diff...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of Glaciology
سال: 1981
ISSN: 0022-1430,1727-5652
DOI: 10.3189/s0022143000011540