Key Number:	HS 15252
Site Name:	Rat's Nest Cave
Other Names:
Site Type:	1911 - Geological Feature

Location

ATS Legal Description:

			Twp	Rge	Mer
			24	9	5

Address:	Canmore - 5 km E near Trans Canada Highway
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Media

Type	Number	Date	View	Source

Architectural

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Exterior:	N/A
Interior:	N/A
Environment:	The cave mouth is located on a gully in the south-facing slope of Grotto Mountain (Section 18 and 19, township 24, Range 9, west of the 5th Meridian), about 5 km east of Canmore.
Condition:	N/A
Alterations:	N/A

Historical

Construction:	Construction Date:
Usage:	Usage Date:
Quarry site	1986/11/01
Owner:	Owner Date:
N/A

Architect:	N/A
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Craftsman:	N/A
History:	Rat's Nest Cave is dissolved out of limestone of the Upper Devonian Palliser Formation. The rock, which is approximately 350 million years old, was uplifted to its present elevation through overthrust faulting during the Laramidian orogeny, 60 million years ago, and again in the Miocene epoch, 40 million years ago. The cave was originally part of a subterranean drainage system formed below the water table long before the development of the present configuration of the Bow Valley corridor. Through erosion and lowering of the base level most of the cave became dry and the precipitation of the travertine began. Uranium/Thorium dating of travertine from other caverns in similar settings indicates that the oldest of the deposits are in excess of 300,000 years old. In portions of the cave, the process is still active. The 'back' portion of the cave contains an extremely fine and extensive development of stalagmites, stalactites, fossil gour dams, soda straws and other travertine deposists. Rat's Nest Cave is a unique example of cave travertine deposits, the most extensive in any readily accessible cave in Alberta. These features, which take many thousands of years to form, are being intentionally damaged. A portion of the cave lies within existing quarry leases. Without some form of effective protective status, this unique geological phenomenon may be lost. * * * Building / Site Description: The Cave The cave mouth is located on a gully in the south - facing slope of Grotto Mountain (Sections 18 and 19, Township 24, Range 9, W_M 5) about 5 km east of Canmore. The cave is phreatic in origin, formed in limestones of the Devonian-age Palliser Formation, about 350 million years old. Although the connection to the outside is a geologically recent event, the cave is believed to have formed not earlier than 40 million, nor less than 2 million years ago. Geological Significance: Rat's Nest Cave is dissolved out of limestone of the Upper Devonian Palliser Formation. The rock, which is approximately 350 million years old, was uplifted to its present elevation through overthrust faulting during the Laramidian orogeny, 60 million years ago, and again in the Miocene epoch, 40 million years ago. The cave was originally part of a subterranean drainage system fomed below the water table long before the development of the present configuration of the Bow Valley corridor. Through erosion and lowering of the base level, most of the cave became dry and the precipitation of travertine began. Uranium/Thorium dating of travertine from other caves in similar settings indicates that the oldest of the deposits are in excess of 300,000 thousand years old. In portions of the cave, the process is still active. The 'back' portion of the cave contains an extremely fine and extensive development of stalagmites, stalactites, fossil gour dams, soda straws and other travertine deposits. Secondary Consideration: Palaeontological Considerations The oldest bone deposits in the lower gallery of the cave have provided radiocarbon dates of 4,470 +/- 90 (AECV-296c), 5,840 +/- 90 (AECV-297c) and 7,600 +/- 110 (AECV-295c). The age and nature of these bone deposits would not in themselves merit designation, from the standpoint of Quarternary palaeontology. They are nevertheless of moderate significance, and enhance the idea of designation on the grounds of geological decoration. Summary: Rat's Nest Cave is a unique example of cave travertine deposits, the most extensive in any readily accessible cave in Alberta. These features, which take many thousands of years to form, are being intentionally damaged. A portion of the cave lies within existing quarry leases. Without some form of effective protective status, this unique geological phenomenon may be lost. AL:MS:4012H 86/10/29

Internal

Designation Status:	Designation Date:
Provincial Historic Resource	1987/03/12

Register:

Links

Internet:
Alberta Register of Historic Places:	4665-0001