GEOLOGICAL PERIODS VS IMPACTS

GEOLOGICAL PERIODS VS IMPACTS
Below I have updated the crater list of known impact craters that R. A. F. Grieve and P. B. Robertson documented in 1979.

PERIOD NAME/PLACE Age (million years) Date Related Extinction Notes
Orosirian Vredefort, South Africa 1,970
Orosirian Sudbury, Ontario, Canada 1,850 Sudbury Distal Ejecta
Cryogenian Janisjarvi, Russia 700
Ediacaran Beaverhead, Idaho, USA ~600
Ediacaran Kelly West, N.T., Australia 550
Ediacaran Holleford, Ontario, Canada 550 Overflight of Holleford Crater
Cambrian Kjardla, Estonia 500
Cambrian Presqu’ile , Quebec, Canada <500 Geological dating
Cambrian Saaksjarvi, Finland 490
Ordovician Carswell, Saskatchewan, Canada 485
Ordovician Clearwater East, Quebec, Canada ~460–470 Possible Multiple Impact?
Ordovician Pilot Lake, N.W.T. Canada 445 Ordovician
Silurian Slate Islands, Ontario, Canada 436 Ordovician
Silurian Rock Elm, Saskatchewan, Canada 420-440 Ordovician
Silurian Lac Couture, Quebec, Canada 425
Devonian Lac La Moinerie, Quebec, Canada 400 Late Devonian
Devonian Brent, Ontario, Canada 396 Late Devonian Overflight of Brent Crater
Devonian Elbow, Saskatchewan, Canada 395 Late Devonian Geological dating
Devonian Siljan, Sweden 365
Devonian Flynn Creek, Tennessee, USA 360
Carboniferous Charlevoix, Quebec, Canada 342 Late Devonian Elevated Earthquake Zone
Carboniferous Crooked Creek, Missouri, USA 320
Carboniferous Middlesboro, Kentucky, USA 300
Carboniferous Serpent Mound, Ohio, USA 300
Carboniferous Ile Rouleau, Quebec, Canada <300 Geological dating
Permian Clearwater West, Quebec, Canada 290 Possible Multiple Impact?
Triassic Gow, Saskatchewan, Canada <250 Permian–Triassic (P–Tr) extinction event
Triassic Kursk, Russia 250
Triassic Dellen, Sweden 230
Triassic St. Martin, Manitoba, Canada 219 Late Triassic
Triassic Manicouagan, Quebec, Canada 214 Late Triassic
Jurassic Red Wing, North Dakota, USA 200 Late Triassic/Triassic-Jurassic
Jurassic Viewfield, Saskatchewan, Canada 190 Triassic-Jurassic
Jurassic Upheaval Dome, Utah, USA <170 Geological dating
Jurassic Vepriaj, Lithuania 160
Jurassic Rochechouart, France 160
Jurassic Strangways, N.T., Australia 150
Cretaceous Carswell, Saskatchewan, Canada 115
Cretaceous Sierra Madre, Texas, USA 100
Cretaceous West Hawk, Ontario, Canada 100 Geological dating
Cretaceous Deep Bay, Saskatchewan, Canada 99 Geological dating
Cretaceous Maple Creek, Saskatchewan, Canada <75 Geological dating
Cretaceous Rotmistrovka, Ukraine 70
Cretaceous Chicxulub, Yucatan, Mexico 66.043 ±0.011 CRETACEOUS-PALEOGENE
Paleogene Eagle Butte, Alberta, Canada <65 Geological dating
Paleogene Kara, Russia 57
Paleogene Montagnais, Nova Scotia, Canada 50
Paleogene Mistastin, Labrador, Canada 36
Paleogene Wanapitei, Ontario, Canada 37
Neogene Haughton Dome, N.W.T., Canada 15
Neogene Karla, Russia 10
Neogene Aouelloul, Mauritania 3.1
Quaternary Pingualuit, Quebec, Canada 1.4 Overflight of Pingualuit Crater
Quaternary Bosumtwi, Ghana 1.3
Quaternary Lonar, India 0.05
Quaternary Barringer, Arizona, USA 0.049 Jointed
Quaternary Whitecourt Alberta, Canada 0.00113

The period dichotomy in terrestrial impact crater ages

Richard B. Stothers

Abstract

Impact cratering on the Earth during the past 250 Myr has occurred with either of two apparent periodicities, ∼30 or ∼35 Myr, depending on the set of impact crater ages that is adopted. When the craters are segregated by size and the possible age errors are explicitly taken into account in the analysis, only the longer periodicity survives, and does so only in the case of the largest craters (diameters ≥ 35 km). Smaller craters exhibit no robust periodicity. Despite their relative abundance, the inclusion of data points for the small craters merely degrades, without shifting or destroying, the periodic signal of the largest craters when all of the craters are analysed together. The possible consequences for quasi-periodic Galactic perturbations of the Oort comet cloud are briefly discussed. (Monthly Notices of the Royal Astronomical Society 01 January 2006)

Impact cratering and the Oort Cloud

J. T. Wickramasinghe & W. M. Napier

Abstract

We calculate the expected flux profile of comets into the planetary system from the Oort Cloud arising from Galactic tides and encounters with molecular clouds. We find that both periodic and sporadic bombardment episodes, with amplitudes an order of magnitude above background, occur on characteristic time-scales ∼25–35 Myr. Bombardment episodes occurring preferentially during spiral arm crossings may be responsible both for mass extinctions of life and the transfer of viable microorganisms from the bombarded Earth into the disturbing nebulae. Good agreement is found between the theoretical expectations and the age distribution of large, well-dated terrestrial impact craters of the past 250 Myr. A weak periodicity of ∼36 Myr in the cratering record is consistent with the Sun’s recent passage through the Galactic plane, and implies a central plane density ∼0.15 M pc−3. This leaves little room for a significant dark matter component in the disc. (Monthly Notices of the Royal Astronomical Society 07 May 2008)

Disc dark matter in the Galaxy and potential cycles of extraterrestrial impacts, mass extinctions and geological events

Michael R. Rampino

Abstract

A cycle in the range of 26–30 Myr has been reported in mass extinctions, and terrestrial impact cratering may exhibit a similar cycle of 31 ± 5 Myr. These cycles have been attributed to the Sun’s vertical oscillations through the Galactic disc, estimated to take from ∼30 to 42 Myr between Galactic plane crossings. Near the Galactic mid-plane, the Solar system’s Oort Cloud comets could be perturbed by Galactic tidal forces, and possibly a thin dark matter (DM) disc, which might produce periodic comet showers and extinctions on the Earth. Passage of the Earth through especially dense clumps of DM, composed of Weakly Interacting Massive Particles (WIMPs) in the Galactic plane, could also lead to heating in the core of the planet through capture and subsequent annihilation of DM particles. This new source of periodic heating in the Earth’s interior might explain a similar ∼30 Myr periodicity observed in terrestrial geologic activity, which may also be involved in extinctions. These results suggest that cycles of geological and biological evolution on the Earth may be partly controlled by the rhythms of Galactic dynamics. (Monthly Notices of the Royal Astronomical Society 18 February 2015)

Periodic impact cratering and extinction events over the last 260 million years

Michael R. Rampino  & Ken Caldeira

Abstract

The claims of periodicity in impact cratering and biological extinction events are controversial. A newly revised record of dated impact craters has been analyzed for periodicity, and compared with the record of extinctions over the past 260 Myr. A digital circular spectral analysis of 37 crater ages (ranging in age from 15 to 254 Myr ago) yielded evidence for a significant 25.8 ± 0.6 Myr cycle. Using the same method, we found a significant 27.0 ± 0.7 Myr cycle in the dates of the eight recognized marine extinction events over the same period. The cycles detected in impacts and extinctions have a similar phase. The impact crater dataset shows 11 apparent peaks in the last 260 Myr, at least 5 of which correlate closely with significant extinction peaks. These results suggest that the hypothesis of periodic impacts and extinction events is still viable. (Monthly Notices of the Royal Astronomical Society 20 October 2015)

A tale of clusters: no resolvable periodicity in the terrestrial impact cratering record

Matthias M. M. Meier & Sanna Holm-Alwmark

Abstract

Rampino & Caldeira carry out a circular spectral analysis (CSA) of the terrestrial impact cratering record over the past 260 million years (Ma), and suggest a ∼26 Ma periodicity of impact events. For some of the impacts in that analysis, new accurate and high-precision (‘robust’; 2SE < 2 per cent) 40Ar-39Ar ages have recently been published, resulting in significant age shifts. In a CSA of the updated impact age list, the periodicity is strongly reduced. In a CSA of a list containing only impacts with robust ages, we find no significant periodicity for the last 500 Ma. We show that if we relax the assumption of a fully periodic impact record, assuming it to be a mix of a periodic and a random component instead, we should have found a periodic component if it contributes more than ∼80 per cent of the impacts in the last 260 Ma. The difference between our CSA and the one by Rampino & Caldeira originates in a subset of ‘clustered’ impacts (i.e. with overlapping ages). The ∼26 Ma periodicity seemingly carried by these clusters alone is strongly significant if tested against a random distribution of ages, but this significance disappears if it is tested against a distribution containing (randomly spaced) clusters. The presence of a few impact age clusters (e.g. from asteroid break-up events) in an otherwise random impact record can thus give rise to false periodicity peaks in a CSA. There is currently no evidence for periodicity in the impact record. (Monthly Notices of the Royal Astronomical Society 25 January 2017)