September 8, 2001 - Expedition by Roman Jirasek

The early long drive just South of the Quebec / Ontario border heading East.


A view from the observation tower, which was originally built in 1972, and is located on the southeast rim of the crater.  The 450 million year old crater is 3.8 km in diameter and is located in Ontario Canada.



The crater viewed from a plane.

Image courtesy of Natural Resources Canada

The Discovery:  Early in 1951, Mr. John A. Roberts, president of Spartan Air Services of Ottawa, was looking over some of the high altitude aerial photos his company had taken for the Government of Canada. He noticed an almost perfectly circular feature straddling the boundary of Algonquin Park north of Brent on Cedar Lake. Since the discovery, over 10 seasons of field work have been conducted by more than a dozen investigators and their assistants, including the diamond drilling of twelve holes and the recovery of some 5,000 meters of drill core, making the Brent Crater among the most thoroughly studied fossil meteorite craters in the world.



Crater hunter Roman Jirasek with a view of the crater floor and opposite rim. I explored and gathered specimens from three different craters on this trip, including BRENT, WANAPITEI, and SUDBURY. Many new km on the old GMC. 


The crater viewed from space.

Image courtesy of Natural Resources Canada

In one second, more than a billion tons of rock were vaporized, melted, or crushed and blasted high into the atmosphere. The result was a huge hole in the earth 4 km wide, 600 meters deep, and with a raised rim of 100 meters above the pre-impact level. The force of the explosion is estimated to have been 250 megatons (equivalent to the explosion of 250 million tons of TNT). Notwithstanding the fantastic destructive energy unleashed in the Brent Crater explosion, the meteorite that caused it was perhaps only 150 meters in diameter. There are reasons to believe the meteorite may have hit the Earth at up to 20 km per second or more. The most advanced creatures present on Earth at that time were marine crustaceans called trilobites. The life forms in and around the crater now are among the most diverse anywhere in the world at this latitude.


Amanita Muscaria - One of many beautiful things I saw this day.  -RJ-




Only a limited supply was available due to the difficulty in acquiring specimens at the crater.


Slices from left to right, top row:

19.2g, 27.3g, 17.1g

bottom row:

19.9g, 14g