The Brent crater is an

impact crater An impact crater is a circular depression in the surface of a solid astronomical object formed by the hypervelocity impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact crater ...

in both the

geographic township The term township, in Canada, is generally the district or area associated with a town. The specific use of the term to describe political subdivisions has varied by country, usually to describe a local rural or semirural government within the co ...

of Deacon,

Unorganized South Nipissing District Unorganized South Nipissing District is an unorganized area in north-central Ontario, in the District of Nipissing. It is almost entirely within and includes most of Algonquin Provincial Park. Localities Localities located within the unorganized ...

and the municipal township of Papineau-Cameron in

Nipissing District Nipissing District is a district in Northeastern Ontario in the Canadian province of Ontario. It was created in 1858. The district seat is North Bay. In 2016, the population was 83,150. The land area is ; the population density was , making it o ...

northeastern Ontario Northeastern Ontario is a secondary region of Northern Ontario in the Canadian province of Ontario, which lies north of Lake Huron and east of Lake Superior. Northeastern Ontario consists of the districts of Algoma, Sudbury, Cochrane, Timiskami ...

, Canada, located north of Cedar Lake in northern

Algonquin Provincial Park Algonquin Provincial Park is a provincial park located between Georgian Bay and the Ottawa River in Ontario, Canada, mostly within the Unorganized South Part of Nipissing District. Established in 1893, it is the oldest provincial park in Can ...

. It is in diameter and the age is estimated to be ca. 453 million years (

Ordovician The Ordovician ( ) is a geologic period and system, the second of six periods of the Paleozoic Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start of the Silurian Period Mya. T ...

). The crater can be reached using Brent Road, south of

Ontario Highway 17 King's Highway 17, more commonly known as Highway 17, is a provincially maintained highway and the primary route of the Trans-Canada Highway through the Canadian province of Ontario. It begins at the Manitoba boundary, west of Kenora, and the ma ...

. A sign, erected at the site by the Archeological and Historic Sites Board, Archives of Ontario, reads:

The Brent Crater: First recognized in 1951 from aerial photographs, the crater is a circular depression about two miles in diameter formed in
Precambrian The Precambrian (or Pre-Cambrian, sometimes abbreviated pꞒ, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of th ...

crystalline A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macros ...
rocks. Geophysical and diamond drilling investigations show that the crater has a present depth of about 1,400 feet but is partly filled with
sedimentary rock Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles ...
s 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 A meteorite is a solid piece of debris from an object, such as a comet, asteroid, or meteoroid, that originates in outer space and survives its passage through the atmosphere to reach the surface of a planet or moon. When the original object ...
. It is calculated that the impact released energy equaling 250 megatons of
TNT Trinitrotoluene (), more commonly known as TNT, more specifically 2,4,6-trinitrotoluene, and by its preferred IUPAC name 2-methyl-1,3,5-trinitrobenzene, is a chemical compound with the formula C6H2(NO2)3CH3. TNT is occasionally used as a reagen ...
and occurred about 450 million years ago when this area was probably covered by a shallow sea.

There is an observation tower on the rim of the crater. The old wooden tower was demolished in July 2007, because it was not safe to use due to its age. A new tower has been built on a hill directly across the Brent Road from the demolished tower. The new tower on the hill offers a much better panorama of the entire crater. Parking will also be increased as part of the new tower improvements. There is a hiking trail leading to the crater floor. There are two small lakes, Gilmour and Tecumseh, located in the crater. Unlike most

Algonquin Park Algonquin Provincial Park is a provincial park located between Georgian Bay and the Ottawa River in Ontario, Canada, mostly within the Unorganized South Part of Nipissing District. Established in 1893, it is the oldest provincial park in Canad ...

lakes, which are usually

acid In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a se ...

ic, the water in these lakes contains

bicarbonate In inorganic chemistry, bicarbonate (IUPAC-recommended nomenclature: hydrogencarbonate) is an intermediate form in the deprotonation of carbonic acid. It is a polyatomic anion with the chemical formula . Bicarbonate serves a crucial biochemi ...

; this is thought to be a result of some

sediment Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand ...

ary deposits of

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms w ...

escaping removal by

glaciers A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires distinguishing features, such as ...

in the lower parts of the crater. The crater lies in the

Ottawa-Bonnechere Graben The Ottawa-Bonnechere Graben (also known as the Ottawa Graben) is a geological structure that coincides with a wide topographic depression extending from near Montréal through Ottawa. It is part of the Saint Lawrence rift system that also includ ...

, a 452 million year old

rift valley A rift valley is a linear shaped lowland between several highlands or mountain ranges created by the action of a geologic rift. Rifts are formed as a result of the pulling apart of the lithosphere due to extensional tectonics. The linear d ...

. The crater was named after the nearby village of Brent.

References

External links

Aerial Exploration of the Brent Structure
{{Impact cratering on Earth Impact craters of Ontario Devonian impact craters Devonian Ontario Landforms of Nipissing District