Tswaing - Hypervelocity Impact Crater

Alternate Names
Local Language Soutpan, Zoutpan (Afrikaans).
Coordinates 25° 24' 31" S; 28° 4' 59" E
Notes
  1. 40 km NNW of Pretoria.
Country South Africa
Region North West
Date Confirmed 1992
Notes
  1. Confirmed by glass fragments and spherules, melt breccia, and PDFs in quartz and feldspar (Reimold et al., 1992).
Buried? No
Drilled? Yes
Notes
  1. Several shallow holes. In 1989, 200 m hole, 125 m NW of centre.
Target Type Crystalline
Notes
  1. Nebo granites of Bushveld Complex (Koeberl et al., 1994).
Sub-Type Granite
Apparent Crater Diameter (km) Unknown
Age (Ma) 0.220 ± 0.104
Notes :
  1. 0.220 ± 0.104 Ma determined by fission track (Storzer et al., 1999) (Jourdan et al., 2007).

Method :
  1. Fission track
Impactor Type Ordinary chondrite, 300,000 tonnes
Notes
  1. Chondrite (Koeberl et al., 1994) (Gaylard, 1996).

Advanced Data Fields

Notes

Erosion
2
  1. Rim still present.
Final Rim Diameter
1.13 km
Apparent Rim Diameter
Unknown
  1. Nearly circular structure with a rim-to-rim diameter of 1130 m (Reimold et al., 1992).
Rim Reliability Index
1
  1. Rim of crater is 60 m above the surrounding plains (Reimold et al., 1992).
Crater Morphology
Simple
Central Uplift Diameter
km
Central Uplift Height
Unknown
Uplift Reliability Index
3
Structural Uplift
Unknown
Thickness of Seds
Target Age
Proterozoic
Marine
No
Impactor Type
Ordinary chondrite, 300,000 tonnes
  1. Chondrite (Koeberl et al., 1994) (Gaylard, 1996).
Other Shock Metamorphism
No
Shatter Cones
No
  1. (Brandt, 1994)
Planar Fractures
No
Planar Deformation Features
Yes
  1. PDF in quartz found in breccia samples from the crater rim, however the original distribution and exact occurrence of the breccia samples is not known (Brandt and Reimold, 1995). PDFs in quartz, alkali feldspar, and plagioclase grains observed in grain mounts prepared from the granitic sands at depths of 90 and 190 m (Reimold et al., 1991) (Reimold et al., 1992).
Diaplectic Glass
Yes
  1. Diaplectic quartz and feldspar (Reimold et al., 1992). Diaplectic quartz glass found in grain mounts prepared from the granitic sands at depths of 90 to 190 m (Reimold et al., 1991) (Reimold et al., 1992).
Coesite
No
  1. (Brandt, 1994)
Stisovite
No
  1. (Brandt, 1994)
Crater Fill
LB, MB
  1. (Reimold and Koeberl, 1992) (Brandt, 1994) P.E., LB: "Ejecta debris (granitic fragmental breccia)" (Brandt, 1994). P.E., M: "A large fraction of melted rock may have been dispersed as part of the ejecta" (Brandt, 1994).
Proximal Ejecta
LB, M
Distal Ejecta
Dykes
Volume of Melt
1x10^-3 km3 to 6x10^-3 km3
Depth of Melting

References

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D J Milton, C W Naeser (1971) Evidence for an impact origin of the Pretoria Salt Pan, South Africa., Nature Physical Science 229, p. 211-212

R F Fudali, D P Gold, J J Gurney (1973) The Pretoria Salt Pan: Astrobleme or Cryptovolcano?, Source: The Journal of Geology 81(4), p. 495-507, url

T Partridge, W U Reimold, F Walraven (1990) The Pretoria Zoutpan crater first results from the 1988 drilling project, Meteoritics, p. 396-396

W U Reimold, C Koeberl, S J Kerr, T C Patridge (1991) The Pretoria Saltpan - The first firm evidence for an origin by impact, Lunar and Planetary Science Conference XXII, p. 1117-1118

W U Reimold, C Koeberl (1992) Pretoria Saltpan impact crater: impact glasses and sulphide spherules, Lunar and Planetary Science Conference XXIII, p. 1139-1140

W U Reimold, C Koeberl, T C Partridge, S J Kerr (1992) Pretoria Saltpan crater: Impact origin confirmed, Geology 20(12), p. 1079-1082

D Brandt, R J Durrheim, W U Reimold (1992) Geophysical signature of the Pretoria Saltpan impact structure and a possible satellite crater, Lunar and Planetary Science Conference XXIV, p. 181-182

T C Partridge, S J Kerr, S E Metcalfe, L Scott, A S Talma, J C Vogel (1993) The Pretoria Saltpan: a 200,000 year Southern African lacustrine sequence, Palaeogeogr., Palaeoclimatol., Palaeoecol 101, p. 317-337

D Storzer, C Koeberl, W U Reimold (1993) The age of the Pretoria Saltpan impact crater, South Africa, Lunar and Planetary Science Conference XXIV, p. 1365-1366

D Brant, W U Reimold (1993) A structural and petrographic investigation of the pretoria saltpan impact structure, Lunar and Planetary Science Conference XXIV, p. 179-180

C Koeberl, D Storzer, W U Reimold (1994) The age of the Saltpan impact crater, South Africa, Meteoritics 29(3), p. 374-379, doi:10.1111/j.1945-5100.1994.tb00600.x

C Koeberl, W U Reimold, S B Shirey (1994) Saltpan impact crater, South Africa: Geochemistry of target rocks, breccias, and impact glasses, and osmium isotope systematics, Geochimica et Cosmochimica Acta 58(13), p. 2893-2922

D Brandt, W U Reimold, C B Smith (1994) Rb-Sr dating of alkaline and mafic intrusives from the Pretoria Saltpan impact crater and environs, Lunar and Planetary Science Conference XXV, p. 161-162

D Brandt, W U Reimold (1995) The geology of the Pretoria Saltpan impact structure and the surrounding area, J.Geol 98(3), p. 287-303

W U Reimold (1995) Impact cratering - a review, with special reference to the economic importance of impact structures and the southern African impact crater record, Earth, Moon and Planets 70, p. 21-45

D Brandt, W U Reimold (1995) The petrology of the igneous rocks occurring in the Pretoria Saltpan impact crater and surrounding area, J.Geol 98(3), p. 304-307

D Brandt, W U Reimold, C B Smith (1996) New Rb-Sr ages for igneous rocks from the area of the Pretoria Saltpan impact crater, South African Journal of Geology 99(3), p. 293-297, Bureau for Scientific Publications, Pretoria

R C de Jong, W U Reimold (1996) The Tswaing Crater museum: developing the Pretoria Saltpan impact crater into an enviromuseum, Meteoritics, p. A35-A35

L P Mccaffrey, C Harris (1996) Hydrological impact of the Pretoria Saltpan crater, South Africa, Pergamon Journal ofAfrican Earth Sciences 23(2), p. 205

B McLean, L Scott (1999) Phytoliths in sediments of the Pretoria Saltpan (Tswaing Crater) and their potential as indicators of the environmental history at the site, Memoir - Geological Survey (Pretoria) 85, T C Partridge (ed.), p. 167-171, Geological Survey of South Africa, Council for Geoscience, Pretoria, url

L Scott (1999) Vegetation history and climate in the savanna biome South Africa since 190,000 ka; a comparison of pollen data from the Tswaing Crater (the Pretoria Saltpan) and Wonderkrater, Quaternary International 57-58, T C Partridge, A Peter Kershaw, Martin H Iriondo (ed.), p. 215-223, Elsevier, Oxford, url

W U Reimold, D Brandt, R C de Jong, J Hancox (1999) The Tswaing meteorite crater; an introduction to the natural and cultural history of the Tswaing region including a description of the hiking trail, Popular Geoscience Series 1, p. 171, Council for Geoscience, Geological Survey of South Africa, Pretoria, url

T C Partridge (1999) Tswaing; investigations into the origin, age and palaeoenvironments of the Pretoria Saltpan, Memoir - Geological Survey (Pretoria) 85, T C Partridge (ed.), p. 198, Geological Survey of South Africa, Council for Geoscience, Pretoria, url

S E Metcalfe (1999) Diatoms from the Pretoria Saltpan; a record of lake evolution and environmental change, Memoir - Geological Survey (Pretoria) 85, T C Partridge (ed.), p. 172-192, Geological Survey of South Africa, Council for Geoscience, Pretoria

D Storzer, W U Reimold, C Koeberl (1999) Fission-track age of the Pretoria Saltpan impact crater, Memoir - Geological Survey (Pretoria) 85, T C Partridge (ed.), p. 64-71, Geological Survey of South Africa, Council for Geoscience, Pretoria

D Brandt, W U Reimold (1999) The geology and geophysical signature of the Pretoria Saltpan (Tswaing) impact structure, Memoir - Geological Survey (Pretoria) 85, T C Partridge (ed.), p. 6-34, Geological Survey of South Africa, Council for Geoscience, Pretoria

C Koeberl (1999) An impact crater for the people; the Tswaing (Saltpan) Crater, South Africa, Meteoritics & Planetary Science 34(6), p. 827-828, Meteoritical Society, Fayetteville, AR

U E Horstmann, D Buehmann (1999) C and O isotopic composition of carbonates from the Pretoria Saltpan (Tswaing) reflecting environmental changes, Memoir - Geological Survey (Pretoria) 85, T C Partridge (ed.), p. 118-126, Geological Survey of South Africa, Council for Geoscience, Pretoria

T C Partridge (1999) The sedimentary record and its implications for rainfall fluctuations in the past, Memoir - Geological Survey (Pretoria) 85, T C Partridge (ed.), p. 127-142, Geological Survey of South Africa, Council for Geoscience, Pretoria

T C Partridge, S E Metcalfe, L Scott (1999) Conclusions and implications for a model of regional palaeoclimates during the last two glacial cycles, Memoir - Geological Survey (Pretoria) 85, T C Partridge (ed.), p. 193-198, Geological Survey of South Africa, Council for Geoscience, Pretoria, url

R C de Jong (1999) Developing the Pretoria Saltpan impact crater into the Tswaing Crater museum, 62nd Annual Meteoritical Society Meeting

H Palme (1999) Age and Palaeo-environments of the Pretoria Saltpan, Geological Survey of South Africa 85, p. 2893-2910

D Brandt (1999) The Tswaing crater one of the worlds best preserved and museum's plans for the site, Meteoritics & Planetary Science 34(4), p. A17-A17

C S Cockell, D Brandt, K Hand, P Lee (2001) Microbial mats of the Tswaing impact crater; results of a South African exobiology expedition and implications for the search for biological molecules on Mars, Abstracts of Papers Submitted to the Lunar and Planetary Science Conference 32, p. abstr. no. 1340, Lunar and Planetary Science Conference, Houston, TX, url

C S Cockell, A K Pavlov (2003) Biological recovery at the site of impact craters; effects of scaling, Astrobiology 3(2), p. 456, Mary Ann Liebert, Larchmont, NY, url

I Kristen, A Fuhrmann, G H Haug, B Horsfield, H Oberhaensli, T C Partridge, J Thorpe, H Wilkes (2005) New insights into the climate and vegetation history of the subtropical crater lake "Tswaing", South Africa, for the last 300,000 years, Eos, Transactions, American Geophysical Union 86(52, Suppl.), p. Abstract PP22A-05, American Geophysical Union, Washington, DC, url

J Thorpe, J Green, I Kristen, M Leng, A Mackay, H Oberhaensli, T Partridge, L Thomas, T Kiefer, C Kull, L Christen (2005) Records of paleoclimatic change from Tswaing crater lake, South Africa, PAGES Open Science Meeting - Abstract Book 2, p. 103, PAGES International Project Office of the International Geosphere-Biosphere Programme (IGBP), [varies]

I Kristen, H Wilkes, A Fuhrmann, H Oberhaensli, G H Haug, B Horsfield, T C Partridge (2006) Climate and vegetation history of the subtropical crater lake "Tswaing" South Africa, Terra Nostra (Bonn) 2006-3, p. 59, Alfred-Wegener-Stiftung, Bonn

I Kristen, H Wilkes, B Plessen, A\ Vieth, J\ Thorpe, H Oberhaensli (2007) Tracing environmental changes in Lake Tswaing (South Africa) using bulk and compound specific stable carbon isotopes, Abstracts of Reports - International Congress on Organic Geochemistry 23, P Farrimond (ed.), p. 1045-1046, [publisher varies], [location varies], url

F Jourdan, P R Renne, W U Reimold (2007) Considerations in dating impact craters using the 40 Ar/ 39 Ar method: The problem of inherited 40 Ar*, Geochimica et Cosmochimica Acta 71(15S), p. 1, Pergamon, Oxford, url

I Kristen, A Fuhrmann, J Thorpe, U Roehl, H Wilkes, H Oberhaensli (2007) Hydrological changes in Southern Africa over the last 200 Ka as recorded in lake sediments from the Tswaing impact crater, South African Journal of Geology 110(2-3), p. 311-326, Bureau for Scientific Publications, Pretoria, url, doi:http://dx.doi.org/10.2113/gssajg.110.2-3.311

F Jourdan, P R Renne, W U Reimold (2007) The problem of inherited 40Ar* in dating impact glass by the 40Ar/39Ar method: Evidence from the Tswaing impact crater (South Africa), Geochimica et Cosmochimica Acta 71(5), p. 1214-1231, url, doi:10.1016/j.gca.2006.11.013

C Koeberl, B Milkereit (2007) Continental drilling and the study of impact craters and processes-an ICDP perspective, Continental Scientific Drilling, p. 95-161, url

T Öhman, M Aittola, V Kostama, J Raitala (2008) The structural control of impact craters; evidence from the terrestrial planets, International Geological Congress, Abstracts = Congres Geologique International, Resumes 33, p. Abstract 1340453, [International Geological Congress], [location varies]

S Master, M Wendorff, B Pitts (2008) Jwaneng South Structure, Botswana; a new 1.3 km diameter buried Cenozoic impact crater, International Geological Congress, Abstracts = Congres Geologique International, Resumes 33, p. Abstract 1343802, [International Geological Congress], [location varies], url

L Scott, K Holmgren, T C Partridge (2008) Reconciliation of vegetation and climatic interpretations of pollen profiles and other regional records from the last 60 thousand years in the savanna biome of Southern Africa, Palaeogeography, Palaeoclimatology, Palaeoecology 257(1-2), p. 198-206, Elsevier, Amsterdam, url, doi:http://dx.doi.org/10.1016/j.palaeo.2007.10.018

I Kristen, H Wilkes, A Vieth, K G Zink, B Plessen, J Thorpe, T C Partridge, H Oberhaensli (2010) Biomarker and stable carbon isotope analyses of sedimentary organic matter from Lake Tswaing; evidence for deglacial wetness and early Holocene drought from South Africa, Journal of Paleolimnology 44(1), p. 143-160, Springer, Dordrecht, url, doi:http://dx.doi.org/10.1007/s10933-009-9393-9

M D Picard (2012) Meteorite impact! The danger from space and South Africa's mega-impact; the Vredefort Structure, AAPG Bulletin 96(3), p. 560-561, American Association of Petroleum Geologists, Tulsa, OK

A A Metwally, L Scott, F H Neumann, M K Bamford, H Oberhaensli (2014) Holocene palynology and palaeoenvironments in the Savanna Biome at Tswaing Crater, central South Africa, Palaeogeography, Palaeoclimatology, Palaeoecology 402, p. 125-135, Elsevier, Amsterdam, url, doi:http://dx.doi.org/10.1016/j.palaeo.2014.03.019

M Di Martino, A Coletta, M L Battagliere, M Virelli (2019) Tswaing, South Africa, Encyclopedic Atlas of Terrestrial Impact Craters, p. 125-127, Springer International Publishing, doi:10.1007/978-3-030-05451-9_24