Holleford crater
Encyclopedia
Meteorite
A meteorite is a natural object originating in outer space that survives impact with the Earth's surface. Meteorites can be big or small. Most meteorites derive from small astronomical objects called meteoroids, but they are also sometimes produced by impacts of asteroids...
crater
Impact crater
In the broadest sense, the term impact crater can be applied to any depression, natural or manmade, resulting from the high velocity impact of a projectile with a larger body...
near the community of Holleford, part of South Frontenac
South Frontenac, Ontario
South Frontenac is a township in eastern Ontario, Canada, in Frontenac County. It was amalgamated in 1998 from the former townships of Bedford, Loughborough, Portland, and Storrington.-Communities:*Battersea* Bedford* Bedford Mills* Bellrock...
, Ontario
Ontario
Ontario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....
, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
. It is 2.35 kilometres (1.5 mi) in diameter
Diameter
In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints are on the circle. The diameters are the longest chords of the circle...
and the age is estimated to be 550 ± 100 million
Million
One million or one thousand thousand, is the natural number following 999,999 and preceding 1,000,001. The word is derived from the early Italian millione , from mille, "thousand", plus the augmentative suffix -one.In scientific notation, it is written as or just 106...
years (Ediacaran
Ediacaran
The Ediacaran Period , named after the Ediacara Hills of South Australia, is the last geological period of the Neoproterozoic Era and of the Proterozoic Eon, immediately preceding the Cambrian Period, the first period of the Paleozoic Era and of the Phanerozoic Eon...
or Cambrian
Cambrian
The Cambrian is the first geological period of the Paleozoic Era, lasting from Mya ; it is succeeded by the Ordovician. Its subdivisions, and indeed its base, are somewhat in flux. The period was established by Adam Sedgwick, who named it after Cambria, the Latin name for Wales, where Britain's...
). Although there is a surface depression over the area, the crater itself is not exposed at the surface.
Holleford Crater was discovered in the 1950s during analysis of aerial photographs
Aerial photography
Aerial photography is the taking of photographs of the ground from an elevated position. The term usually refers to images in which the camera is not supported by a ground-based structure. Cameras may be hand held or mounted, and photographs may be taken by a photographer, triggered remotely or...
under the direction of Dr. Carlyle S. Beals of the Dominion Observatory
Dominion Observatory
The Dominion Observatory was an astronomical observatory in Ottawa, Canada that operated from 1902 to 1970. The Observatory was also an institution within the Canadian Federal Government. The observatory grew out of the Department of the Interior's need for the precise coordinates and timekeeping...
in Ottawa
Ottawa
Ottawa is the capital of Canada, the second largest city in the Province of Ontario, and the fourth largest city in the country. The city is located on the south bank of the Ottawa River in the eastern portion of Southern Ontario...
, Canada. In the late 1950s, the Geological Survey of Canada conducted a series of four geophysical
Geophysical survey
Geophysical survey is the systematic collection of geophysical data for spatial studies. Geophysical surveys may use a great variety of sensing instruments, and data may be collected from above or below the Earth's surface or from aerial or marine platforms. Geophysical surveys have many...
studies: (1) magnetic
Magnetometer
A magnetometer is a measuring instrument used to measure the strength or direction of a magnetic field either produced in the laboratory or existing in nature...
observations; (2) seismic
Reflection seismology
Reflection seismology is a method of exploration geophysics that uses the principles of seismology to estimate the properties of the Earth's subsurface from reflected seismic waves. The method requires a controlled seismic source of energy, such as dynamite/Tovex, a specialized air gun or a...
studies; (3) gravity
Exploration geophysics
Exploration geophysics is the applied branch of geophysics which uses surface methods to measure the physical properties of the subsurface Earth, in order to detect or infer the presence and position of ore minerals, hydrocarbons, geothermal reservoirs, groundwater reservoirs, and other geological...
studies; and (4) a diamond drilling
Drilling rig
A drilling rig is a machine which creates holes or shafts in the ground. Drilling rigs can be massive structures housing equipment used to drill water wells, oil wells, or natural gas extraction wells, or they can be small enough to be moved manually by one person...
program. The seismic and gravity studies and the drilling all produced data consistent with the impact theory. The drill core
Core sample
A core sample is a cylindrical section of a naturally occurring substance. Most core samples are obtained by drilling with special drills into the substance, for example sediment or rock, with a hollow steel tube called a core drill. The hole made for the core sample is called the "core hole". A...
revealed breccia
Breccia
Breccia is a rock composed of broken fragments of minerals or rock cemented together by a fine-grained matrix, that can be either similar to or different from the composition of the fragments....
and similar materials at predicted depths. The studies concluded that an ancient meteorite impact crater is present in the Precambrian
Precambrian
The Precambrian is the name which describes the large span of time in Earth's history before the current Phanerozoic Eon, and is a Supereon divided into several eons of the geologic time scale...
bedrock below the surface. The meteorite was estimated to be approximately 800 meters in diameter and to have impacted at approximately 55 thousand kilometers per hour.
Location
Holleford Crater is located on the Babcook Family Homestead Farm properties (including the original Babcook Homestead Farm, established 1803, owned by the family of the late Frederick and Jean Babcook, at Hartington, OntarioHartington, Ontario
Hartington is a small village in South Frontenac Township, located about 14.5 miles north of Kingston, Ontario, Canada on Provincial Route 38 . It was formerly a stop on the Kingston and Pembroke Railway. It is notable as being close to the Holleford meteor crater....
(about 1/2 hour north of Kingston Ontario).
Starting in the 1960s, the site has been visited frequently by geology students from Queen's University
Queen's University
Queen's University, , is a public research university located in Kingston, Ontario, Canada. Founded on 16 October 1841, the university pre-dates the founding of Canada by 26 years. Queen's holds more more than of land throughout Ontario as well as Herstmonceux Castle in East Sussex, England...
, at Kingston. In the 1970s, as a result of efforts by the late Frederick Babcook, an official commemorative plaque was erected along the road beside the Babcook Homestead Farm by the Province of Ontario. Queen's University's Miller Hall Museum of Geology maintains a display dedicated to the Holleford Meteorite Crater.