"THE BRENT CRATER"
Posted by: 
entogeek
N 46° 04.010 W 078° 27.496
17T E 696572 N 5104614
This plaque is located near the base of the Brent Crater viewing platform in northern Algonquin Park.
Waymark Code: WM9TN1
Location: Ontario, Canada
Date Posted: 09/28/2010
Views: 10
The plaque reads:
First recognized in 1951 from aerial photographs, the crater
is a circular depression about two miles in diameter formed
in Precambrian crystalline rocks. Geophysical and diamond
drilling investigations show that the crater has a present
depth of about 1,400 feet but is partly filled by sedimentary
rocks with a thickness of 900 feet. The rocks beneath the
crater floor are thoroughly fragmented over a depth of 2,000
feet. Like the similar New Quebec (Chubb) crater, the Brent
crater is attributed to the high speed impact of a giant meteorite.
It is calculated that the impact released energy equalling 250
megatons of TNT and occurred about 450 million years ago
when this area was probably covered by a shallow sea.
Address or location of plaque: Brent Road approximately 32 km south of Hwy. 17
Physical location of plaque: Park
"Ontario Plaques" Website for this "Plaque": [Web Link]
Description of any physical remains at site of "Historical Plaque": Crater depression
This 'Plaque' describes: An 'Event'
Condition of sign: Needs cleaning
Is this a bilingual sign?: No !
A web-site for more details.: Not listed
What is the second/third language?: Not listed
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Visit Instructions:
A "Visited" only remark, will be deleted.
No Waymark owner "Visits" allowed when setting up the Waymark.
Subsequent visits, at another time with photo are acceptable.
NOTE: All photos must include the 'O.H.P.Plaque' at its location to qualify for a "Visited"