MANICOUAGAN IMPACT STRUCTURE

References and Notes

REFERENCES

Kenneth Amor, Stephen P. Hesselbo, Don Porcelli, Scott Neil Thackrey, John Parnell, A Precambrian proximal ejecta blanket from Scotland GEOLOGY, April 2008

AMOR, Kenneth, HESSELBO, Stephen P., and PORCELLI 2005, GEOCHEMICAL ANALYSIS OF A LATE TRIASSIC DISTAL IMPACT EJECTA LAYER FROM SW ENGLAND. Donald Department of Earth Sciences, University of Oxford.

Brent Dalrymple, Radiometric Dating Does Work! Reports of the National Center for Science Education

Michael J. Clutson, David E. Brown, Lawrence H Tanner Distal Processes and Effects of Multiple Late Triassic Terrestrial Bolide Impacts: Insights from the Norian Manicouagan Event, Northeastern Quebec, CanadaResearch Gate 2018

M.H.L. Deenen, M. Ruhl, N.R. Bonis,W. Krijgsman, W.M. Kuerschner, M. Reitsma, M.J. van Bergen, A new chronology for the end-Triassic mass extinction. Earth and Planetary Science Letters 2009.

Dence, M.R., Bunch T.E. Cohen A.J. NATURAL TERRESTRIAL MASKELYNITE, THE AMERICAN MINERALOGIST 1967

Dence, M. R. 1976 The Manicouagan impact structure. NASA Spec. Pub.

Kord Ernstson, Gravity surveys of impact structures 2009

French, Bevan M. 1998. Traces of Catastrophe, A handbook of Shock-Metamorphic effects, Lunar and Planetary Institute.

R. A. F. Grieve et al , Manicouagan Impact Melt, Quebec, 1, Stratigraphy, petrology, and chemistry 1978

Grieve and Head, 1983. R.A.F. Grieve and J.W. Head, The Manicouagan impact structure: An analysis of its original dimensions and form. PROCEEDINGS OF THE THIRTEENTH LUNAR AND PLANETARY SCIENCE CONFERENCE, PART 2

Haskin, L et al 1998, The case for an Imbrium origin of the Apollo thorium-rich impact-melt breccias. Meteoritics & Planetary Science, vol. 33, no. 5, pp. 959-975.

Murtaugh, J.G. 1972, Shock metamorphism in the Manicouagan cryptoexplosion structure, Quebec. Proc. 24th Int. Geol. Congr.

O’Dale, C.P. 2006; Manicouagan Impact Structure

Onoue T. et al; Deep-sea record of impact apparently unrelated to mass extinction in the Late Triassic. National Academy of Sciences, 2012

Onoue T. et al; Bolide impact triggered the Late Triassic extinction event in equatorial Panthalassa. Scientific Reports, 2016

Tetsuji Onouea, et al; Deep-sea record of impact apparently unrelated to mass extinction in the Late Triassic. Rutgers University/Lamont-Doherty Earth Observatory, Palisades, NY, October 3, 2012

Orphal, D & Schultz, P, An alternative model for the Manicouagan impact structure. Proc Lunar Planet Sci Conf 1978.

Simonds, C.H. et al 1976, Thermal model for impact breccia lithification: Manicouagan and the moon. Proc. Lunar Sci. Conf. 7th (1976) p. 2509-2528.

Smith, R. Dark days of the Triassic: Lost world – Did a giant impact 200 million years ago trigger a mass extinction and pave the way for the dinosaurs? NATURE 17 Nov. Vol#479 2011.

Tanner, Lawrence Synsedimentary seismic deformation in the Blomidon Formation (Norian-Hettangian), Fundy basin, Canada 2006, The Triassic-Jurassic Terrestrial Transition

L. M. Thompson, J. Brown and J. G. Spray, SHATTER CONES, SHOCK ATTENUATION AND FELDSPARS: MANICOUAGAN IMPACT STRUCTURE, CANDA. 79th Annual Meeting of the Meteoritical Society (2016)

Earth Impact Database

NOTES

PHOTOGRAPHIC IMAGES: Eric Kujala and Charles O’Dale.

2021 December Update: A possible explanation for Manicouagan NOT being related to an extinction event.

Meteorites that produce K-feldspar-rich ejecta blankets correspond to mass extinctions

M.J. Pankhurst, C.J. Stevenson and B.C. Coldwell

Abstract:

Meteorite impacts load the atmosphere with dust and cover the Earth’s surface with debris. They have long been debated as a trigger of mass extinctions throughout Earth history. Impact winters generally last <100 years, whereas ejecta blankets persist for 10³ –10⁵ years. We show that only meteorite impacts that emplaced ejecta blankets rich in K-feldspar (Kfs) correlate to Earth system crises (n = 11, p < 0.000005). Kfs is a powerful ice-nucleating aerosol, yet is normally rare in atmospheric dust mineralogy. Ice nucleation plays an important part in cloud microphysics, which modulates the global albedo.

A conceptual model is proposed whereby the anomalous presence of Kfs post impact is posited to have two key effects on cloud dynamics:

(1) Kfs reduces the average albedo of mixed-phase clouds, which leads to a hotter climate; and

(2) Kfs weakens the cloud albedo feedback mechanism, which increases climate sensitivity.

These mechanisms offer an explanation as to why this otherwise benign mineral is correlated so strongly with mass extinction events: every Kfs-rich ejecta blanket corresponds to a severe extinction episode over the last 600 myr. This model may also explain why many kill mechanisms only variably correlate with extinction events through geological time: they coincide with these rare periods of climate destabilization by atmospheric Kfs.

There is a strong similarity between the profiles of the Can-Am structure and the Manicouagan Impact Crater. The coincidence between magnetic and gravity signatures strongly suggests a common source for both fields. This data documents that the Precambrian basement rocks are interrupted by anomalies that clearly outline the circular nature of the structure and provides evidence that the remnants of a complex meteorite crater is situated in the south end of Lake Huron.

EARTH SCIENCE PICTURE OF THE DAY

- MANICOUAGAN – BRECCIA
- MANICOUAGAN – IMPACT MELT

RASC 150

The RASC Sesquicentennial Logo featuring the Manicouagan Impact Crater.

Components of the RASC Sesquicentennial Logo:

The aurora borealis is a quintessentially Canadian space-weather phenomenon, one shared with other high latitude cultures. RASC members have contributed to the scientific, historical, and artistic investigation of the northern lights, and have promoted their recreational enjoyment.

The Manicouagan astrobleme (214 ± 1 Ma) represents the major discovery of sites of impact cratering in the Canadian Shield, an effort pioneered by astrophysicists and geophysicists at the Dominion Observatory (ca. 1950-), many of whom were RASC members. This world-impacting research played a crucial role in changing scientific and popular perceptions of crater-forming mechanisms, solar-system history, and planetary geology. The representation of the crater also acknowledges Canadian excellence in meteor dynamics, meteorite petrology, meteorite curation, and the RASC’s long-standing interest in such work.

The stars represent the major Canadian contributions to stellar spectroscopy done at the Dominion Observatory, the Dominion Astrophysical Observatory (also see this), the David Dunlap Observatory,(additionally refer to this) and elsewhere (ca. 1905-), whose major contributors were also RASC members (such as J.S. Plaskett [1865-1941], the first Canadian astrophysicist of international repute). The stars also symbolize the asteroseismology, exoplanet transits and eclipses, and investigations into stellar variability through precise photometry achieved by the Microvariability and Oscillations of STars space telescope(MOST, 2003-).

The globular cluster recognizes the field of Helen Sawyer Hogg‘s (1905-1993) greatest scientific contributions (ca. 1926-ca. 1993), and the Helen Sawyer Hogg Telescope (HSHT) at the University of Toronto Southern Observatory at Cerro Las Campanas, one of Canada’s first ventures (1971-1997) in exploring off-shore astronomical installations, which has born lasting fruit in international cooperative installations exploring the full range of astrophysical phenomena, such as the Canada-France-Hawaii Telescope (CFHT, 1979-), the James Clerk Maxwell Telescope (JCMT, 1986-2015 [period of direct Canadian involvement & funding]), the Gemini Telescopes (North 1999-, South 2000-), the Atacama Large Millimetre Array (ALMA, 2011/2013-), the Square Kilometre Array (SKA, 2020-), and the Thirty Metre Telescope (TMT, ca. 2022-).

The spiral galaxy represents both the work of Canadian observational cosmologists (e.g., Sidney van den Bergh‘s classification of Galaxy morphology, Laura Ferrarese‘s work on the morphology & dynamics of early type galaxies), as well as the efforts of amateur Canadian observers of deep-sky objects (DSOs), and imagers.

The comet stands for the contributions to cometography by Canadian comet discoverers, such as David Levy, Rolf Meier, and Chris Wilson.

The Moon symbolizes an object important for first nations’ calendrics, and the earliest recorded observations by Europeans in Canada (17th century lunar reports, and lunar eclipse reports). The Moon together with the stars symbolizes the practice of navigational astronomy on land and water, which was crucial to the formation of Canada. Finally, the Moon is as popular an object for RASC members to share with the public when doing outreach as it was 150 years ago.

R.A. Rosenfeld

RASC AstroNotes Article (September 2010)

from (AstroNotes October 2010😉 – I included the geology from our exploration of the Manicouagan Impact Crater as examples for “Identifying Impact Craters/Structures”.

~214 Ma – LATE TRIASSIC EXTINCTION

Scientists reported in the journal Nature today (March 13, 1998) that they had found evidence of a chain of five craters formed 214 million years ago that was likely due to pieces of a comet crashing into the Earth’s surface, similar to the Comet Shoemaker-Levy 9 impact on Jupiter in 1994. The craters no longer appear to be in a straight line due the shifting of the Earth’s continents due to plate tectonics. Two of the craters, Manicouagan and Saint Martin, are in Canada (Quebec and Manitoba, respectively). The other three craters are Rochechouart in Europe, Obolon in the Ukraine and Red Wing in Minnesota. The impacts appeared to occur at the Norian stage of the Triassic period, about six million years after a mass extinction that wiped out 80% of all the species on Earth, but the ages of all the craters are uncertain enough to include this extinction (from ScienceWeb Daily).

Abstract:

The 34-million-year (My) interval of the Late Triassic is marked by the formation of several large impact structures on Earth. Late Triassic impact events have been considered a factor in biotic extinction events in the Late Triassic (e.g., end-Triassic extinction event), but this scenario remains controversial because of a lack of stratigraphic records of ejecta deposits. Here, we report evidence for an impact event (platinum group elements anomaly with nickel-rich magnetite and microspherules) from the middle Norian (Upper Triassic) deep-sea sediment in Japan. This includes anomalously high abundances of iridium, up to 41.5 parts per billion (ppb), in the ejecta deposit, which suggests that the iridiumenriched ejecta layers of the Late Triassic may be found on a global scale. The ejecta deposit is constrained by microfossils that suggest correlation with the 215.5-Mya, 100-km-wide Manicouagan impact crater in Canada. Our analysis of radiolarians shows no evidence of a mass extinction event across the impact event horizon, and no contemporaneous faunal turnover is seen in other marine planktons. However, such an event has been reported among marine faunas and terrestrial tetrapods and floras in North America. We, therefore, suggest that the Manicouagan impact triggered the extinction of terrestrial and marine organisms near the impact site but not within the pelagic marine realm (Onoue, Tetsuji, October 2012).

Summary of impact structures in the Late Triassic.

A) Map showing the palaeo-position and distribution of the Central Atlantic Magmatic Province (CAMP) and the studied sections in the US, Morocco and UK in pre-drift position for the end-Triassic. B) Summary of the correlation-tools used to correlate the terrestrial and marine sections. Main events recognized in the different sections are shown in italic. GPTS: Geomagnetic Polarity Time Scale.

DINOSAUR EVOLUTION AT THE END-TRIASSIC (Tr-J) vs END-CRETACEOUS (K-Pg) EXTINCTIONS

Bolide impact triggered the Late Triassic extinction event in equatorial Panthalassa

(a) Late Triassic generic diversities of radiolarians, conodonts, and Pacific (North American) ammonoids, as compared with the Os isotope record in the Panthalassa Ocean. The abrupt decrease in the ¹⁸⁷Os/¹⁸⁸Os ratio in the middle Norian is synchronous with the Manicouagan impact event at 214–215 Ma. Stepwise or episodic extinctions in the (1) end-middle Norian, (2) end-Norian, and (3) end-Triassic are possibly linked with a large bolide impact, an oceanic anoxic event (OAE), and the Central Atlantic Magmatic Province (CAMP) volcanic event, respectively. The gradual decrease in radiolarian diversity just prior to the end-middle Norian may have occurred within radiolarian biozone 6B. Gray shaded areas in the radiolarian and conodont generic diversities represent the number of genera; the genera first appear in the upper Norian and Rhaetian. (b) Late Triassic palaeogeographic map showing approximate locations of the Manicouagan crater and the inferred depositional area of the bedded chert in the Mino Belt, in low-latitude zones of the Panthalassa Ocean. The map is created using ACD Systems Canvas Draw software (Version 2.0).

ABSTRACT
Extinctions within major pelagic groups (e.g., radiolarians and conodonts) occurred in a stepwise fashion during the last 15 Myr of the Triassic. Although a marked decline in the diversity of pelagic faunas began at the end of the middle Norian, the cause of the middle Norian extinction is uncertain. Here we show a possible link between the end-middle Norian radiolarian extinction and a bolide impact. Two palaeoenvironmental events occurred during the initial phase of the radiolarian extinction interval: (1) a post-impact shutdown of primary and biogenic silica production within a time span of 10⁴–10⁵ yr, and (2) a sustained reduction in the sinking flux of radiolarian silica for ~0.3 Myr after the impact. The catastrophic collapse of the pelagic ecosystem at this time was probably the dominant factor responsible for the end-middle Norian conodont extinction. (Onoue 2016)

Distal Processes and Effects of Multiple Late Triassic Terrestrial Bolide Impacts: Insights from the Norian Manicouagan Event, Northeastern Quebec, Canada

ABSTRACT
The Late Triassic (Carnian to Rhaetian Stages: ca. 237–201 Ma) has a long history of geological research, although controversy remains over the precise definition of key sub-unit boundaries, including those defining the three constituent stages. Within this context, at least five terrestrial bolide impact structures ranging from 9 to 85 km in diameter have been identified at present-day northern latitudes, the proximal remnant crater aspects of which have been studied in increasing detail over the last few decades. The more elusive distal sedimentary expressions of these multi-sized hypervelocity events remain largely unknown, although if preserved, identified and interpreted correctly, may (as precisely dateable event horizons) help to address certain existing stratigraphic uncertainties, particularly pertaining to the (longest) Norian Stage. Detailed absolute age-dating using a range of radioisotopic methods (e.g. U-Pb and 40Ar/39Ar) currently indicates that at least three of the confirmed Late Triassic impact craters formed prior to commencement of the major Rhaetian Central Atlantic Magmatic Province (CAMP) volcanic episode by several million years. Impact research efforts to date have focused mainly on describing and process modeling the relatively well-preserved largest impact structure, Manicouagan (215.5 Ma; 85 km diameter) located in northeastern Quebec, Canada and, to a lesser extent, the Saint Martin (227.8 Ma; 40 km) and Rochechouart (ca. 207–201 Ma; ca. 23–50 km) structures in central Manitoba, Canada and west-central France respectively. The smaller, subsurface Red Wing structure (ca. 200 Ma; 9 km diameter, ca. 2.5 km burial depth) located in South Dakota, USA, also has attracted significant economic interest. Unlike the well-documented End Cretaceous Chicxulub impact (66 Ma; ca. 180 Km), attempts to establish a globally significant causal extinction connection between the larger impacts (e.g. Manicouagan and Rochechouart) and Late Triassic marine and terrestrial bioevents, culminating with the ‘End Triassic Extinction’ (ETE), have essentially proved unsuccessful. (David E. Brown ET AL 2018)

DISTAL EVIDENCE (?) OF THE LATE TRIASSIC (NORIAN) MANICOUAGAN IMPACT, NORTHEASTERN QUEBEC: NEW DATA FROM THE FUNDY GROUP (CANADIAN MARITIMES)

December 2017
Conference: 53rd Annual GSA Northeastern Section Meeting – 2018
Lawrence H Tanner, Michael J. Clutson, David E. Brown

Late Triassic (210 Ma) paleogeographic map showing the Manicouagan impact crater location in relation to key North American sedimentary basins, containing the (cored) Newark Supergroup and Chinle Group lithofacies units among other successions. The general locations of the eastern Canadian (Fundy Group) and southwestern British (Mercia Mudstone Group) sections discussed in Sect. 5.4 are highlighted. (Modified from Blakey 2014)

8. REFERENCES

[see – METEORITE]