Search results
Results from the WOW.Com Content Network
Drumlins and drumlin swarms are glacial landforms composed primarily of glacial till. They form near the margin of glacial systems, and within zones of fast flow deep within ice sheets , and are commonly found with other major glacially-formed features (including tunnel valleys , eskers , scours, and exposed bedrock erosion ).
Drumlin. Drumlins form as overlying ice moves across unconsolidated till or ground moraines. There are two main theories for the formation of drumlins. Although the exact origins of these landforms may vary circumstantially and is a topic of debate. [38]
Drumlins and ribbed moraines are also landforms left behind by retreating glaciers. Many depositional landforms result from sediment deposited or reshaped by meltwater and are referred to as fluvioglacial landforms. Fluvioglacial deposits differ from glacial till in that they were deposited by means of water, rather than the glacial itself, and ...
Drumlins are found in groups called drumlin fields or drumlin camps. One of these fields is found east of Rochester, New York; it is estimated to contain about 10,000 drumlins. Although the process that forms drumlins is not fully understood, their shape implies that they are products of the plastic deformation zone of ancient glaciers.
Also called Indianite. A mineral from the lime-rich end of the plagioclase group of minerals. Anorthites are usually silicates of calcium and aluminium occurring in some basic igneous rocks, typically those produced by the contact metamorphism of impure calcareous sediments. anticline An arched fold in which the layers usually dip away from the fold axis. Contrast syncline. aphanic Having the ...
The Withrow Moraine and Jameson Lake Drumlin Field is a National Park Service–designated privately owned National Natural Landmark located in Douglas County, Washington state, United States. [1] Withrow Moraine is the only Ice Age terminal moraine on the Waterville Plateau section of the Columbia Plateau.
Till plains are also the location in which drumlins, drumlin fields, flutes, and additional moraines form, all composed of glacial till. [4] The material composition of till plains vary greatly, and is dependent on the travel path of the transporting glacier, indicated by the provenance of the deposited material.
The soil of Seattle, the state's largest city, is approximately 80% glacial drift, most of which is Vashon glacial deposits , [7] and nearly all of the city's major named hills are characterized as drumlins (Beacon Hill, First Hill, Capitol Hill, Queen Anne Hill) or drift uplands (Magnolia, West Seattle).