Pantasma: Evidence for a Pleistocene circa 14 km diameter impact crater in Nicaragua

The circa 14 km diameter Pantasma circular structure in Oligocene volcanic rocks in Nicaragua is here studied for the first time to understand its origin. Geomorphology, field mapping, and petrographic and geochemical investigations all are consistent with an impact origin for the Pantasma structure...

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Main Authors: Rochette, P., Alac, R., Beck, P., Brocard, G., Cavosie, Aaron, Debaille, V., Devouard, B., Jourdan, F., Mougel, B., Moustard, F., Moynier, F., Nomade, S., Osinski, G., Cornec, J.
Format: Journal Article
Published: John Wiley & Sons, Inc. 2019
Online Access:http://hdl.handle.net/20.500.11937/73930
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author Rochette, P.
Alac, R.
Beck, P.
Brocard, G.
Cavosie, Aaron
Debaille, V.
Devouard, B.
Jourdan, F.
Mougel, B.
Moustard, F.
Moynier, F.
Nomade, S.
Osinski, G.
Cornec, J.
author_facet Rochette, P.
Alac, R.
Beck, P.
Brocard, G.
Cavosie, Aaron
Debaille, V.
Devouard, B.
Jourdan, F.
Mougel, B.
Moustard, F.
Moynier, F.
Nomade, S.
Osinski, G.
Cornec, J.
author_sort Rochette, P.
building Curtin Institutional Repository
collection Online Access
description The circa 14 km diameter Pantasma circular structure in Oligocene volcanic rocks in Nicaragua is here studied for the first time to understand its origin. Geomorphology, field mapping, and petrographic and geochemical investigations all are consistent with an impact origin for the Pantasma structure. Observations supporting an impact origin include outward‐dipping volcanic flows, the presence of former melt‐bearing polymict breccia, impact glass (with lechatelierite and low H2O, <300 ppm), and also a possible ejecta layer containing Paleozoic rocks which originated from hundreds of meters below the surface. Diagnostic evidence for impact is provided by detection in impact glass of the former presence of reidite in granular zircon as well as coesite, and extraterrestrial ε54Cr value in polymict breccia. Two 40Ar/39Ar plateau ages with a combined weighted mean age of 815 ± 11 ka (2 σ; P = 0.17) were obtained on impact glass. This age is consistent with geomorphological data and erosion modeling, which all suggest a rather young crater. Pantasma is only the fourth exposed crater >10 km found in the Americas south of N30 latitude, and provides further evidence that a significant number of impact craters may remain to be discovered in Central and South America.
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format Journal Article
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institution Curtin University Malaysia
institution_category Local University
last_indexed 2025-11-14T10:58:39Z
publishDate 2019
publisher John Wiley & Sons, Inc.
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spelling curtin-20.500.11937-739302019-08-22T03:27:02Z Pantasma: Evidence for a Pleistocene circa 14 km diameter impact crater in Nicaragua Rochette, P. Alac, R. Beck, P. Brocard, G. Cavosie, Aaron Debaille, V. Devouard, B. Jourdan, F. Mougel, B. Moustard, F. Moynier, F. Nomade, S. Osinski, G. Cornec, J. The circa 14 km diameter Pantasma circular structure in Oligocene volcanic rocks in Nicaragua is here studied for the first time to understand its origin. Geomorphology, field mapping, and petrographic and geochemical investigations all are consistent with an impact origin for the Pantasma structure. Observations supporting an impact origin include outward‐dipping volcanic flows, the presence of former melt‐bearing polymict breccia, impact glass (with lechatelierite and low H2O, <300 ppm), and also a possible ejecta layer containing Paleozoic rocks which originated from hundreds of meters below the surface. Diagnostic evidence for impact is provided by detection in impact glass of the former presence of reidite in granular zircon as well as coesite, and extraterrestrial ε54Cr value in polymict breccia. Two 40Ar/39Ar plateau ages with a combined weighted mean age of 815 ± 11 ka (2 σ; P = 0.17) were obtained on impact glass. This age is consistent with geomorphological data and erosion modeling, which all suggest a rather young crater. Pantasma is only the fourth exposed crater >10 km found in the Americas south of N30 latitude, and provides further evidence that a significant number of impact craters may remain to be discovered in Central and South America. 2019 Journal Article http://hdl.handle.net/20.500.11937/73930 John Wiley & Sons, Inc. restricted
spellingShingle Rochette, P.
Alac, R.
Beck, P.
Brocard, G.
Cavosie, Aaron
Debaille, V.
Devouard, B.
Jourdan, F.
Mougel, B.
Moustard, F.
Moynier, F.
Nomade, S.
Osinski, G.
Cornec, J.
Pantasma: Evidence for a Pleistocene circa 14 km diameter impact crater in Nicaragua
title Pantasma: Evidence for a Pleistocene circa 14 km diameter impact crater in Nicaragua
title_full Pantasma: Evidence for a Pleistocene circa 14 km diameter impact crater in Nicaragua
title_fullStr Pantasma: Evidence for a Pleistocene circa 14 km diameter impact crater in Nicaragua
title_full_unstemmed Pantasma: Evidence for a Pleistocene circa 14 km diameter impact crater in Nicaragua
title_short Pantasma: Evidence for a Pleistocene circa 14 km diameter impact crater in Nicaragua
title_sort pantasma: evidence for a pleistocene circa 14 km diameter impact crater in nicaragua
url http://hdl.handle.net/20.500.11937/73930