Monturaqui - Hypervelocity Impact Crater

Alternate Names
Local Language
Coordinates 23° 55' 60" S; 68° 16' 60" W
Notes
  1. Near the S end of the Salar de Atacama in N Chile, 70 km N of the town of Monturaqui.
Country Chile
Region Antofagasta
Date Confirmed 1966
Notes
  1. Confirmed by meteoric iron shale found in the south and southeast flanks of the crater (Sanchez and Cassidy, 1966). PDFs in qurtaz subsequently reported (Bunch and Cassidy, 1972).
Buried? No
Notes
  1. Alluvium fills the structure's depression (Bunch and Cassidy, 1972).
Drilled? No
Target Type Crystalline
Notes
  1. Jurassic granite overlain unconformably by a few meters of Upper Tertiary to Pleistocene ignimbrite (Sanchez and Cassidy, 1966).
Sub-Type Granite
Apparent Crater Diameter (km) Unknown
Age (Ma) 0.663 ± 0.023
Notes :
  1. 663 ± 23 ka (2σ) obtained from (U-Th)/He on zircon and apatite from impact breccia (Ukstins et al, 2021). Previous age constraints: 663 ± 90 ka obtained from (U-Th)/He of zircon and apatite (Ukstins Peate et al., 2010). 500-600 ka obtained from 36Cl and 26Al cosmogenic radionuclides on iron shale (Valenzuela et al., 2009). 780 ka suggested by Palaeomagnetic measurements of granite (Valenzuela et al., 2009). 200-250 ka minimum age obtained from 10Be cosmogenic on quartz from granite within the crater (Valenzuela et al. 2009) 590 ± 120 ka obtained from thermoluminescence of quartz from impactite (Verdugo and Cartes, 2000). Pleistocene-recent (~2.58 Ma-recent) based on impact disrupting drainage pattern in the Upper Tertiary to Pleistocene ignimbrites (Sanchez and Cassidy, 1966).

Method :
  1. (U-Th)/He
Impactor Type Iron, IAB
Notes
  1. Impactites contain an abundance of Ni-Fe and sulphide spherules, as well as oxide minerals; possibly an octahedrite (Bunch and Cassidy, 1972). Meteorites recovered.

Advanced Data Fields

Notes

Erosion
2
  1. A significant period of erosion has followed formation of the crater, although some ejecta and most of the crater-fill product is preserved (Bunch and Cassidy, 1972).
Final Rim Diameter
470 m
Apparent Rim Diameter
Unknown
  1. The average diameter of the crater is 460 m where its dimensions are more specifically 470 m E-W by 440 m N-S (Sanchez and Cassidy, 1966)
Rim Reliability Index
1
  1. Consists of a nearly circular derpession with a partial rim (Sanchez and Cassidy, 1966).
Crater Morphology
Simple
Central Uplift Diameter
km
Central Uplift Height
Unknown
Uplift Reliability Index
1
Structural Uplift
Unknown
Thickness of Seds
Target Age
Mesozoic Cenozoic
Marine
No
Impactor Type
Iron, IAB
  1. Impactites contain an abundance of Ni-Fe and sulphide spherules, as well as oxide minerals; possibly an octahedrite (Bunch and Cassidy, 1972). Meteorites recovered.
Other Shock Metamorphism
Maskelynite
  1. (Bunch and Cassidy, 1972)
Shatter Cones
No
Planar Fractures
No
Planar Deformation Features
Yes
  1. PDF in quartz and plagioclase (Bunch and Cassidy, 1972).
Diaplectic Glass
No
Coesite
Yes
  1. (Bunch and Cassidy, 1972)
Stisovite
No
Crater Fill
M
  1. Melt rocks are described as "cindery, highly vesicular agglomerations of shocked and unshocked granite fragments and nickel-iron and sulphide spherules tightly bound in a highly heterogenoeus glass matrix" (Bunch and Cassidy, 1972). According to the descriptions, the recovered samples are not in situ/outcrops (they are fragments within the crater) (Bunch and Cassidy, 1972) (Ukstins Peate et al., 2010) (Cukierski, 2013).
Proximal Ejecta
Distal Ejecta
Dykes
Volume of Melt
Depth of Melting

References

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J Sanchez, W A Cassidy (1966) A previously undescribed meteorite crater in Chile, Journal of Geophysical Research 71(20), p. 4891-4895, American Geophysical Union, Washington, DC, url

Ted E Bunch, W A Cassidy (1972) Petrographic and electron microprobe study of the Monturaqui impactite, Contributions to Mineralogy and Petrology 36(2), p. 95-112, doi:10.1007/BF00371181

C B Koch (1991) Weathering of impactite from Monturaqui, Program and Abstracts - Annual Clay Minerals Conference 28, p. 91, Clay Minerals Society, url

J Lipka, H G Jensen, J M Knudsen, M B Madsen, M D Bentzon, C B Koch, S Morup (1992) A Mossbauer Study of an impactite from the Monturaqui Crater, Hyperfine Interactions 70, p. 965-968

C B Koch, V F Buchwald (1994) Weathering of iron meteorites form Monturaqui, Chile, Meteoritics 29(4), Derek W G Sears (ed.), p. 443, Meteoritical Society, Fayetteville, AR, url

J Lipka, M B Madsen, C B Koch, M Miglierini, J M Knudsen, S Morup, M B Bentzon (1994) The Monturaqui impactite and the iron in it, Meteoritics

H Ugalde, M Valenzuela, E Casas, B Milkereit, M Grandon, S Contrereas (2004) New Geological and Geophysical Antecedents at the Monturaqui Impact Crater, Chile, AGU Fall Meeting Abstracts

J C Echaurren, A C Ocampo, M C L Rocca (2005) A mathematic model for the Monturaqui impact crater, Chile, South America, Meteoritics & Planetary Science 40, Suppl., p. 1, Meteoritical Society, Fayetteville, AR, url

H Ugalde, M Valenzuela, B Milkereit (2007) An integrated geophysical and geological study of the Monturaqui impact crater, Chile, Meteoritics & Planetary Science 42(12), p. 2153-2163, url, doi:10.1111/j.1945-5100.2007.tb01015.x

M Valenzuela, P Rochette, D L Bourlès, R Braucher, T Faestermann, R C Finkel, J Gattacceca, G Korschinek, S Merchel, D Morata, M Poutivtsev, G Rugel, C Suavet (2009) The age of the Monturaqui impact crater, Meteoritics & Planetary Science 44, SUPPL., p. Abstract 5185, Meteoritical Society, Fayetteville, AR, url

C M Kloberdanz, I Ukstins Peate, D W Peate, Nathalie A Cabrol, E Grin (2009) Geochemical investigations of the Monturaqui impact crater, Chile, Eos, Transactions, American Geophysical Union 90(22, Suppl.), p. Abstract GA33B-05, American Geophysical Union, Washington, DC, url

I Ukstins Peate, C Kloberdanz, D W Peate, L C Wan, Nathalie A Cabrol, E Grin, J Piatek, G Chong (2010) Non-modal melting of target rocks to produce impactite at Monturaqui crater, Chile, Abstracts of Papers Submitted to the Lunar and Planetary Science Conference 41, p. Paper 2089, Lunar and Planetary Science Conference, Houston, TX, url

J L Piatek, Ukstins Peate, Nathalie A Cabrol, E A Grin, G Chong (2010) Monturaqui Crater (Atacama Desert, Chile) as a Mars analog: Exploring the impact spherule hypothesis for Meridiani, Abstracts of Papers Submitted to the Lunar and Planetary Science Conference 41, p. Abstract 2236, Lunar and Planetary Science Conference, Houston, TX, url

D W Peate, I U Peate, L C Wan, C Kloberdanz (2011) Compositional variations and petrography of metallic spherules in melt rock at Monturaqui crater, Chile, Abstracts with Programs - Geological Society of America 43(5), p. 307, Geological Society of America (GSA), Boulder, CO, url

I U Peate, M C van Soest, J A Wartho, N Cabrol, E Grin, J Piatek, G Chong (2011) A novel application of (U-Th)/He geochronology to constrain the age of small, young meteorite impact craters: A case study of Monturaqui crater, Chile, Mineralogical Magazine 75(3), p. 2047, Mineralogical Society, London, url

D Cukierski, D W Peate, I Ukstins Peate (2012) Origin of Fe-Ni metal spherules in impact melt at the Monturaqui impact crater, Chile, Abstracts with Programs - Geological Society of America 44(7), p. 276, Geological Society of America (GSA), Boulder, CO, url

S Kaniansky, K Molnár (2013) Monturaqui impact crater, IMC, Poznan, p. 208-209

K C Rathburn, I Ukstins Peate, S Drop (2017) Monturaqui meteorite impact crater, Chile: A field test of the utility of satellite-based mapping of ejecta at small craters, AGU Fall Meeting Abastracts, p. EP53B-1731, url

M Valenzuela, J Benada (2018) Meteorites and craters found in Chile: A bridge to introduce the first attempt for geoheritage legal protection in the country, Geoethics In Latin America, p. 103-115, Springer, Cham, url, doi:https://doi.org/10.1007/978-3-319-75373-7_7

S Staffieri, A Coletta, M L Battagliere, M Virelli (2019) Monturaqui, Chile, Encyclopedic Atlas of Terrestrial Impact Craters, p. 665-669, Springer, Cham, url, doi:https://doi.org/10.1007/978-3-030-05451-9_185

K C Rathbun (2020) Monturaqui meteorite impact crater, Chile: a terrestrial analog for small craters on Mars, url, doi:https://doi.org/10.17077/etd.005565

I Ukstins, J A Wartho, N A Cabrol, E A Grin, M C van Soest, M B Biren, K V Hodges, G Chong (2021) An (U-Th)/He age for the small Monturaqui impact structure, Chile, Quaternary Geochronology, p. 101217, url, doi:10.1016/j.quageo.2021.101217