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For example, one large glacial erratic in Germany measures 3 by 6 km (2 by 4 mi) and is 9 m (30 ft) thick. [10] Near Cooking Lake, Alberta , one of several large glacial erratics, which is called the Cooking Lake (Number 6) megablock , covers an area of at least 10 km 2 (4 sq mi), has a length of 4.0 km (2.5 mi) and is about 10 m (33 ft) thick.
The Canadian Arctic Rift System is a branch of the Mid-Atlantic Ridge that extends 4,800 km (3,000 mi) into the North American continent. It is an incipient structure that diminishes in degree of development northwestward, bifurcates at the head of Baffin Bay and disappears into the Arctic Archipelago.
The Ottawa-Bonnechere Graben measures about 700 km (435 mi), running from the Montreal area on the east to near Sudbury and Lake Nipissing on the west. [2] On the east, it joins the Saint Lawrence rift system, a half-graben which extends more than 1000 km along the Saint Lawrence River valley and links the Ottawa and Saguenay Graben.
Most of the bedrock in the Hudson Bay lowlands is composed of limestone and carbonate-dominated sedimentary rock. [7] Besides Ontario it also forms parts of the bedrock of Michigan and Minnesota. The Midcontinent Rift System formed 1.1 billion years ago when the Craton split open and formed the basin of Lake Superior.
The Midcontinent Rift System (MRS) or Keweenawan Rift is a 2,000 km (1,200 mi) long geological rift in the center of the North American continent and south-central part of the North American plate. It formed when the continent's core, the North American craton , began to split apart during the Mesoproterozoic era of the Precambrian , about 1.1 ...
The Rio Grande rift is a north-trending continental rift zone. It separates the Colorado Plateau in the west from the interior of the North American craton on the east. [1] The rift extends from central Colorado in the north to the state of Chihuahua, Mexico, in the south. [2]
Mountaintop removal mining (MTR), also known as mountaintop mining (MTM), is a form of surface mining that involves the topographical alteration and/or removal of a summit, hill, or ridge to access buried coal seams. The MTR process involves the removal of coal seams by first fully removing the overburden lying atop them, exposing the seams ...
In geology, a rift is a linear zone where the lithosphere is being pulled apart [1] [2] and is an example of extensional tectonics. [3] Typical rift features are a central linear downfaulted depression, called a graben , or more commonly a half-graben with normal faulting and rift-flank uplifts mainly on one side. [ 4 ]