A probable meteorite crater of Precambrian age at Holleford, Ontario

Beals, C. S.

doi:10.4095/8727

Cited by 13 publications

(46 citation statements)

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“…Historically, symmetric residual gravity lows over the apparent floor of terrestrial simple impact structures indicated reduced densities, suggesting brecciation beneath the apparent floor. This was confirmed by drilling at several simple craters, which recovered cores of breccia, e.g., Holleford, West Hawk, and Brent, Canada (Beals 1960;Halliday and Griffin 1967;Dence 1968) and Lonar, India (Fredriksson et al 1973). …”

Section: Form: Not That Simplementioning

confidence: 77%

Observations at terrestrial impact structures: Their utility in constraining crater formation

Grieve

Therriault

2004

Meteorit & Planetary Scien

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Abstract-Hypervelocity impact involves the near instantaneous transfer of considerable energy from the impactor to a spatially limited near-surface volume of the target body. Local geology of the target area tends to be of secondary importance, and the net result is that impacts of similar size on a given planetary body produce similar results. This is the essence of the utility of observations at impact craters, particularly terrestrial craters, in constraining impact processes. Unfortunately, there are few well-documented results from systematic contemporaneous campaigns to characterize specific terrestrial impact structures with the full spectrum of geoscientific tools available at the time. Nevertheless, observations of the terrestrial impact record have contributed substantially to fundamental properties of impact. There is a beginning of convergence and mutual testing of observations at terrestrial impact structures and the results of modeling, in particular from recent hydrocode models. The terrestrial impact record provides few constraints on models of ejecta processes beyond a confirmation of the involvement of the local substrate in ejecta lithologies and shows that Z-models are, at best, first order approximations. Observational evidence to date suggests that the formation of interior rings is an extension of the structural uplift process that occurs at smaller complex impact structures. There are, however, major observational gaps and cases, e.g., Vredefort, where current observations and hydrocode models are apparently inconsistent. It is, perhaps, time that the impact community as a whole considers documenting the existing observational and modeling knowledge gaps that are required to be filled to make the intellectual breakthroughs equivalent to those of the 1970s and 1980s, which were fueled by observations at terrestrial impact structures. Filling these knowledge gaps would likely be centered on the later stages of formation of complex and ring structures and on ejecta.

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Section: Form: Not That Simplementioning

confidence: 77%

Observations at terrestrial impact structures: Their utility in constraining crater formation

Grieve

Therriault

2004

Meteorit & Planetary Scien

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“…In Canada, the well-preserved New Quebec crater furnishes important data on rim structure and other aspects of the surface expression of such craters, while subsurface information has been obtained from three others by diamond drilling. Of the latter, the two smaller, Holleford (Beals 1960) and West Hawk Lake (Halliday and Griffin 1967;Short 1970), exemplify craters formed, respectively, in Grenville Province marbles and other metasediments and Superior Province greenstones. However, the extensive drilling at the 3.8 km Brent crater, Ontario (Fig.…”

Section: General Characteristicsmentioning

confidence: 99%

Structural evidence from shock metamorphism in simple and complex impact craters: Linking observations to theory

Dence¹

2004

Meteorit & Planetary Scien

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Abstract-The structure of Canadian impact craters formed in crystalline rocks is analyzed using shock metamorphism and evidence for movement along shear zones. The analysis is based on an interpretation that, beyond the near field region, shock pressure attenuates down axis as P ~ R −2 , in agreement with nuclear test and computed results, and as P ~ R −3 near the surface. In both simple and complex craters, the transient cavity is defined by the limit of fragmentation due to direct and reflected shock waves. The intersection of the transient cavity with hemispheric shock isobars indicates that the transient cavity has a parabolic form. Weakening by dilation during early uplift allows late stage slumping of the walls of simple craters. This is controlled by a spheroidal primary shear of radius r s ≈ 2d t , where d t is the depth of the transient crater due to excavation and initial compression. With increasing crater diameter, the size of the transient cavity decreases relative to the shock imprint, suggesting that fragmentation and excavation is limited by progressively earlier collapse of the margins under gravity. Central peak formation in complex craters may be initiated by relaxation of the shock-compressed central parautochthone, so the primary shear, lubricated by friction melting, meets below the crater floor and drives the continuing upward motion.

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“…Study with a stereoscope revealed a relatively shallow circular depression about 100 feet (30 m) deep and about 1.46 miles (2.35 km) in diameter, with some indication of a raised rim. Beals took a personal interest in the study of this crater, and published the principal paper on its investigation (Beals 1960).…”

Section: Significance Of Meen's Workmentioning

confidence: 99%

V. Ben Meen and the Riddle of Chubb Crater

Plotkin

Tait

2011

Earth Sciences History

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Aerial photographs of Chubb Crater, a striking 3.4 km-wide circular basin in the far north of Quebec, led the Ontario prospector Fred W. Chubb to think it might be an extinct volcano, and possibly the site of a diamond-bearing diatreme. V. Ben Meen, the Director of the Royal Ontario Museum of Geology and Mineralogy in Toronto, however, suspected it was an impact crater caused by a meteorite. Meen led two expeditions to the crater in 1950 and 1951. Despite early opposition and the initial absence of corroborative field evidence, he held on to a persistent belief in the crater's meteoritic origin. Later fieldwork ultimately provided strong evidence in support of this view. The discovery of the crater led to the development of a program at the Dominion Observatory in Ottawa to search for additional impact craters on the Canadian Shield, and the development of valuable criteria by which they could be authenticated. The craters discovered through the program fit well on the Baldwin curve relating crater depth to diameter, and lent strong support to the argument for the relationship between the meteoritic origin of lunar craters and terrestrial impact structures. Chubb Crater is of historical importance because it was the first meteorite crater to be recognized in Canada, and the first anywhere to be authenticated in the absence of associated meteorites.

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A probable meteorite crater of Precambrian age at Holleford, Ontario

Cited by 13 publications

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Observations at terrestrial impact structures: Their utility in constraining crater formation

Observations at terrestrial impact structures: Their utility in constraining crater formation

Structural evidence from shock metamorphism in simple and complex impact craters: Linking observations to theory

V. Ben Meen and the Riddle of Chubb Crater

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