Pantasma - Hypervelocity Impact Crater

Alternate Names Valle di Santa Maria di Pantasma (Rochette et al., 2019).
Local Language
Coordinates 13° 22' 12" N; 85° 57' 0" W
Notes
  1. Located in the volcanic Nicaragua Highlands. Structure is strongly dissected by the Pantasma River.
Country Nicaragua
Region Jinotega
Date Confirmed 2019
Notes
  1. Confirmed based on the presence of FRIGN zircon and coesite from impact glass (Rochette et al., 2019).
Buried? No
Drilled? No
Target Type Crystalline
Notes
  1. Oligocene volcanics surround the impact structure (Rochette et al., 2019).
Sub-Type Basalt
Apparent Crater Diameter (km) 14 km
Age (Ma) 0.815 ± 0.011
Notes :
  1. 0.815 ± 0.011 Ma determined by 40Ar/39Ar of impact glass (Rochette et al., 2019).

Method :
  1. 40Ar/39Ar
Impactor Type Unknown

Advanced Data Fields

Notes

Erosion
3
  1. Some of the rim remains and possible ejecta material may be preserved (Rochette et al., 2019).
Final Rim Diameter
0 km
  1. The circular structure has a diameter of ~14 km (Rochette et al., 2019).
Apparent Rim Diameter
14 km
Rim Reliability Index
1
  1. Located in a highly erodible and wet tropical area may have eroded the central peak, or peak is possibly buried (Rochette et al., 2019).
Uplift Type
Complex
Central Uplift Diameter
km
Central Uplift Height
0 km
Uplift Reliability Index
Structural Uplift
0 km
Thickness of Seds
Target Age
Cenozoic
Marine
No
Impactor Type
Other Shock Metamorphism
FRIGN zircon
  1. The presence of former reidite phase in zircon called FRIGN zircon was detected (Cavosie et al., 2018; Rochette et al., 2019).
Shatter Cones
No
  1. Pervasive fracturing but no convincing shatter cones were observed (Rochette et al., 2019).
Planar Fractures
Yes
  1. Quartz fragments from possible ejecta layer are strongly deformed with numerous planar fractures (Rochette et al., 2019).
Planar Deformation Features
No
  1. PDFs in quartz were not identified in possible ejecta layer samples (Rochette et al., 2019).
Diaplectic Glass
No
Coesite
Yes
  1. Coesite was identified in impact glass using Raman spectroscopy (Rochette et al., 2019).
Stisovite
No
Crater Fill
LB, MB
  1. Polymict breccia at the centre of the structure contains altered melt fragments that broadly resemble suevite. Possible ejecta layer contains Palaeozoic rocks which would have originated hundreds of metres below the surface (Rochette et al., 2019).
Proximal Ejecta
LB
Distal Ejecta
Dykes
Volume of Melt
Depth of Melting

References

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A J Cavosie, N E Timms, Ludovic Ferrière, P Rochette (2018) Former reidite in granular neoblastic zircon (FRIGN zircon) from the Luizi impact structure and proposed Pantasma structure, 49th Lunar and Planetary Science Conference, p. Abstract 1816, Lunar and Planetary Science Conference, Houston, TX

A J Cavosie, N E Timms, Ludovic Ferrière, P Rochette (2018) FRIGN zircon—The only terrestrial mineral diagnostic of high-pressure and high-temperature shock deformation, Geology 46(10), p. 891-894, Geological Society of America, doi:10.1130/G45079.1

P Rochette, R Alaç, P Beck, G Brocard, A J Cavosie, V Debaille, B Devouard, F Jourdan, B Mougel, F Moustard, F Moynier, S Nomade, G R Osinski, B Reynard, J Cornec (2019) Pantasma: Evidence for a pleistocene circa 14 km diameter impact crater in Nicaragua, Meteoritics and Planetary Science 901(4), p. 880-901, doi:10.1111/maps.13244