Quantifying the Release of Climate-Active Gases by Large Meteorite Impacts With a Case Study of Chicxulub

Natalia Artemieva; Joanna Morgan;

doi:10.1002/2017gl074879

Quantifying the Release of Climate-Active Gases by Large Meteorite Impacts With a Case Study of Chicxulub

Geophysical Research Letters ◽

10.1002/2017gl074879 ◽

2017 ◽

Vol 44 (20) ◽

pp. 10,180-10,188 ◽

Cited By ~ 30

Author(s):

Natalia Artemieva ◽

Joanna Morgan ◽

Keyword(s):

Meteorite Impacts ◽

Large Meteorite

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Large Meteorite Impacts and Planetary Evolution, 1992 August 31-September 2, Sudbury, Canada

Meteoritics ◽

10.1111/j.1945-5100.1992.tb01072.x ◽

1992 ◽

Vol 27 (5) ◽

pp. 489-489

Author(s):

R. A. F. Grieve

Keyword(s):

Meteorite Impacts ◽

Planetary Evolution ◽

Large Meteorite

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Zircon Microstructures Record Deformation History of Shock- and Tectonically-generated Pseudotachylites: a Case Study from the Vredefort Impact Structure, South Africa

Journal of Petrology ◽

10.1093/petrology/egaa017 ◽

2019 ◽

Vol 60 (12) ◽

pp. 2529-2546 ◽

Cited By ~ 1

Author(s):

E Kovaleva ◽

M S Huber ◽

G Habler ◽

D A Zamyatin

Keyword(s):

Tectonic Deformation ◽

Impact Structure ◽

Deformation Bands ◽

Deformation History ◽

Meteorite Impacts ◽

History Of ◽

Tectonic Settings ◽

New Criterion

Abstract High-strain rate deformation can cause in situ melting of rocks, resulting in the formation of dark, micro- to nanocrystalline pseudotachylite veins. On Earth, pseudotachylite veins form during meteorite impacts, large landslides, and earthquakes. Within the Vredefort impact structure, both impact-generated and (pre-impact) tectonically-generated pseudotachylite veins have been described, but are challenging to distinguish. Here, we demonstrate a genetic distinction between two pseudotachylite veins from Vredefort by studying their petrography, degree of recrystallization and deformation, cross-cutting relationships and the deformation microstructures in associated zircon. We conclude that Vein 1 is pre-impact and tectonically-generated, and Vein 2 is impact-generated. In agreement, zircon microstructures in Vein 1 contain planar deformation bands (PDBs), attributed to tectonic deformation, whereas zircon microstructures in Vein 2 reveal microtwin lamellae, indisputable evidence of shock metamorphism. Thus, deformation microstructures in zircon may provide a new criterion for distinguishing the genetic origin of pseudotachylite veins. Zircons that have been removed from their context (i.e., alluvial or detrital zircon, zircon from Lunar breccia) should be interpreted with caution in terms of their deformation history. For example, zircon with PDBs cannot reliably be used as a marker for shock deformation, because this feature has been shown to form in purely tectonic settings.

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