Decaturville - Hypervelocity Impact Crater

Alternate Names
Local Language
Coordinates 37° 53' 45" N; 92° 43' 10" W
Notes
  1. The Ozark Plateau of central Missouri, about 13 km S of Camdenton and Lake of the Ozarks.
Country United States of America
Region Missouri
Date Confirmed 1977
Notes
  1. Presence of shatter cones and PDF's in quartz (Offield and Pohn, 1977).
Buried? No
Drilled? Yes
Notes
  1. 55 drill holes, ranging from 15 to 190 m in depth, total more than 5.5 km of core penetrating breccia, deformed sediments and crystalline basement (Offield and Pohn, 1979).
Target Type Mixed
Notes
  1. 0.54 km of Cambrian dolomite, limestone, sandstone Precambrian overlying granite pegmatites and schist. Sandstones, carbonates, and granitic basement; deformed Silurian sediments through to Precambrian granitic rocks are recognized (Offield and Pohn, 1979).
Sub-Type Carbonate, Plutonic, Sandstone
Apparent Crater Diameter (km) 6 km
Age (Ma) < 323
Notes :
  1. Pennsylvanian to mid-Permian impact age determined by palaeomagnetic dating. A modified conglomerate test was used to assess the timing and origin of the magnetization relative to deposition of breccia (Elmore and Dunlin, 2007). Additional age constraints: The Zainbridge Limestone is involved in the deformation, so based on stratigraphy the Decaturville structure is younger than Middle Silurian, so <430 Ma. The age of mineralization within the breccia is at most Late Pennsylvanian, <323 Ma (Offield and Pohn, 1979).

Method :
  1. Palaeomagnetism
Impactor Type Unknown

Advanced Data Fields

Notes

Erosion
5
  1. Partial preservation of the crater-fill products (Offield and Pohn, 1979).
Final Rim Diameter
Unknown
Apparent Rim Diameter
6 km
  1. Reconstructed dimensions are from diagram of (Offield and Pohn, 1979) and are for the transient cavity.
Rim Reliability Index
3
  1. Consists of a central uplift surrounded by a structurally depressed zone 1.6 km in width and 75 m deep (Offield and Pohn, 1979). Uplift diameter and stratigraphic uplift values from (Offield and Pohn, 1979).
Crater Morphology
Complex
Central Uplift Diameter
2.4 3.35km
Central Uplift Height
Unknown
Uplift Reliability Index
3
Structural Uplift
550 m
Thickness of Seds
0.54 km
Target Age
Precambrian Palaeozoic
Marine
No
Impactor Type
Other Shock Metamorphism
Planar features
  1. see "Planar Elements in Quartz" page 30 (Offield and Pohn, 1979). (**in Figure 22) quartz grain with dominant planar features spaced 1-3 µm and oriented parallel to {1013} (Offield and Pohn, 1979). Planar features in quartz (Offield and Pohn, 1979). Quartz grains with planar features (Offield and Pohn, 1977). In very few grains planar features are oriented parallel to {1013} (Offield and Pohn, 1977)."
Shatter Cones
Yes
  1. Shatter cones occur (Dietz, 1963). An aerial photograph with the approximate limit of shatter cones at surface is reported in (Offield and Pohn, 1979), p. 20; well-developed cones are exposed at surface in outcrops of Derby and Doe Run dolomites within an elliptical area measuring ~420 by 480 m (Offield and Pohn, 1979). The deepest occurence of shatter cones in drill cores is reportd within dolomite blocks at 250 m deep (in hole C-27). Cones are typically 2.5-5 cm high, and high as ~25 cm in pegmatite outcrop (Offield and Pohn, 1979). "Double cones pointing in opposite directions from a common base, or single cones pointing opposite to the general mass of cones in an outcrop occur but are not common (Offield and Pohn, 1979). Shatter cone clasts also occur within the "mixed breccia" (shatter cones clasts developed in Potosi, Derby, and Doe Run dolomites) (Offield and Pohn, 1979). Apical angles ranged from 79 to 92°, with a mean of 86° (Offield and Pohn, 1979). Shatter cones, see Figure 14 (Amstutz, 1965b). Derby and Doe Run Dolomites are intensely shatter-coned shatter cones (Offield and Pohn, 1977). Central zone containing abundant shatter cones (Snyder and Gerdemann, 1965). Shatter cones are abundant in the central part of the structure. They occur in a bleached, dead-tan dolomite (Snyder and Gerdemann, 1965).
Planar Fractures
Yes
  1. Quartz planar fractures (Offield and Pohn, 1979). Planar fractures probably make up no more than 2-3% of the quartz (Offield and Pohn, 1977).
Planar Deformation Features
Yes
  1. PDF in quartz grains (Amstutz, 1965b) (Offield and Pohn, 1979).
Diaplectic Glass
No
  1. Did not find in literature.
Coesite
No
  1. Did not find in literature.
Stisovite
No
  1. Did not find in literature.
Crater Fill
LB, MB
  1. Monomict and polymict LB (Offield and Pohn, 1977). MB from (Beauford, 2012), the melt portion is supposedly carbonate. 'Some zones within the core sections of mixed breccia are notable because of their flowage features. The matrix is finely banded and clearly shows folds and swirls and the characteristic of wrapping around intricately sculpted edges of fragments. In places, dolomite fragments surrounded by flow-banded material themselves seem to have been drawn out plastically to become irregular schlieren with ragged flamelike ends' (Offield and Pohn, 1977). Melt rocks?
Proximal Ejecta
Distal Ejecta
Dykes
Volume of Melt
Depth of Melting

References

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W A Tarr (1935) The origin of the Decaturville dome, Camden County, Missouri, Proceedings of the Missouri Academy of Science 1, p. 99-101, Missouri Academy of Science, Columbia, MO, url

H B Graves (1938) The Pre-Cambrian structure of Missouri, Transactions of the Academy of Science of St. Louis 29(5), p. 111-164, url

D S Krishnaswamy, G C Amstutz (1960) Geology of the Decaturville disturbance in Missouri, Bulletin of the Geological Society of America 71(12, Part 2), p. 1910, Geological Society of America (GSA), Boulder, CO, url

T H Kiilsgaard, A V Heyl, M R Brock (1963) The Crooked Creek disturbance, Southeast Missouri, U. S. Geological Survey Professional Paper, p. E14-E19, U. S. Geological Survey, Reston, VA, url

G C Amstutz (1965) Tectonic and petrographic observations on polygonal structures in Missouri, Annals of the New York Academy of Sciences 123(2), p. 876-894, Wiley/Blackwell (10.1111), url, doi:10.1111/j.1749-6632.1965.tb20406.x

F G Snyder, P E Gerdemann (1965) Explosive igneous activity along an Illinois-Missouri-Kansas axis, American Journal of Science 263(6), p. 465-493, Kline Geology Laboratory, Yale University, New Haven, CT, url

R A Zimmermann, G C Amstutz (1965) The polygonal structure at Decaturville, Missouri; new tectonic observations, Neues Jahrbuch fuer Geologie und Palaeontologie. Monatshefte 9, p. 288-307, E. Schweizerbart'sche Verlagsbuchhandlung, Stuttgart, url

G C Amstutz, R A Zimmermann (1966) Decaturville sulfide breccia of south-central Missouri; a fossil mud volcano, Special Paper - Geological Society of America, p. 4, Geological Society of America (GSA), Boulder, CO, url

T W Offield, H A Pohn, C W Naeser (1970) The character and origin of the Decaturville, Missouri, cryptoexplosion structure, Geological Society of America 2, p. 639

T W Offield, H A Pohn (1971) Style and sequence of deformation at the Decaturville, Missouri impact structure, Meteoritics 6(4), p. 296-297, Arizona State University, Center for Meteorite Studies, Tempe, AZ, url

R A Zimmermann, G C Amstutz (1972) The Decaturville Sulfide Breccia; a Cambro-Ordovician Mud Volcanoe, Chemie der Erde 31(3-4), p. 253-274, Gustav Fischer Verlag, Jena, url

T W Offield, H A Pohn (1977) Deformation at the Decaturville impact structure, Missouri, Lunar Science Institute topical conference ; Symposium on planetary cratering mechanics, D J Roddy, R O Pepin, R B Merrill (ed.), p. 321-341, Pergamon Press, New York, N.Y., url

T W Offield, H A Pohn (1979) Geology of the Decaturville impact structure, Missouri, U. S. Geological Survey Professional Paper, p. 48, U. S. Geological Survey, Reston, VA, url

R A F Grieve (1982) The record of impact on Earth: Implications for a major Cretaceous/Tertiary impact event, Geological Society of America 190(Special Paper), p. 25-37, url

B A Ivanov, A T Bazilevskiy, L V Sazonova (1982) Formation of the central uplift in meteorite craters, Meteoritika 40, p. 67-81, url

O N Shcherban (1985) A study of meteorite crater formation by comparing results of geological observations and numerical modelling on the computer, Visnyk Akademiyi Nauk Ukrayinskoyi RSR 3, p. 11-19, url

Y P Gurov, Y P Gurova (1987) Impact structures on the Earth's surface, Geologicheskiy Zhurnal 47(1), p. 117-124, Naukova Dumka, Kiev, url

L P Khryanina (1987) Meteorite craters on Earth, Moscow, Nedra, p. 56-58

G A J Nickerson, J G Spray, L A Mayer (2001) Investigation of integrated geologic and geophysical data using GIS; Crooked Creek and Decaturville impact structures, Missouri, Atlantic Geology 36(1), p. 67-68, Atlantic Geoscience Society, Fredericton, NB, url

R E Beauford (2012) Carbonate melts and sedimentary impactite variation at Crooked Creek and Decaturville impact craters, Missouri, USA., 43rd Lunar and Planetary Science Conference, p. 1705, Lunar and Planetary Science Conference, url

J D Newman, G R Osinski (2018) Investigation of Carbonate-Rich Breccias and Their Emplacement in the Central Uplift of the Decaturville Impact Structure, Missouri, 49th Lunar and Planetary Science Conference, p. 2880, pdf