Astronomy:Czech Crater
Czech Crater or Bohemian Crater is a working hypothesis that considers the Bohemian Massif as an approximately 2 billion year old impact crater. This is contrary to mainstream geological ideas that describe the Massif as the result of continental collision. Individual independent units collided more than 300 million years ago thanks to their drifting. This is explained by a widely accepted theory of plate tectonics.
Evolution of the Hypothesis
A first comparison of the craters on the Moon and the Czech circular structure was made by Galileo Galilei in 1610.[1] Boston University astronomers Farouk El-Baz and Michael D. Papagiannis informed about the structure in 1980's as well.[2] So did also Petr Rajlich in 1992.[3] He informed about the discovery of an impact breccia. Rajlich, Benes and Cobbold also proposed a tectonic experiment related to the hypothesis in 1996.[4] They demonstrated the origin of roughly circular ridges around the Bohemian Massif as a result of simple lithospheric wrenching.
There exist many results of radiometric dating from the Bohemian Massif like zircon, muscovite or monazite ages. The age is often around 340 million years (a presumed variscan orogeny). The rocks could only be affected by a late variscan hydrothermal event and the ages of zircons or monazites do not indicate the real ages of them according to some papers.[5]
There was found a large conical depression in the Moho discontinuity 2-D model just beneath the probable center of the crater according to seismic data.[6]
Rajlich's Hypothesis
Macroscopic white lamellae exist inside quartz and other minerals in the Bohemian Massif and even at another places in whole of the world like wavefronts generated by a meteorite impact according to the Rajlich's Hypothesis.[7][8][9] The hypothetical wavefronts are composed of many microcavities. Their origin is seen in a physical phenomenon of ultrasonic cavitation, which is well known from the technical practice.
References
- ↑ Galilei, Galileo (1610). Sidereus Nuncius.
- ↑ "1989LPICo.712..189P Page 189". http://adsabs.harvard.edu/full/1989LPICo.712..189P.
- ↑ Rajlich, Petr (1992). "Bohemian circular structure, Czechoslovakia: Search for the impact evidence". Lunar and Planetary Inst., International Conference on Large Meteorite Impacts and Planetary Evolution: 57–59. https://ntrs.nasa.gov/search.jsp?R=19930000984.
- ↑ "Wrenching of a Continental Lithosphere Containing a Circular Resistant Inclusion: Physical Model Experiments (PDF Download Available)" (in en). https://www.researchgate.net/publication/267381280_Wrenching_of_a_Continental_Lithosphere_Containing_a_Circular_Resistant_Inclusion_Physical_Model_Experiments.
- ↑ "Younger postectonic monazite in the Písek pegmatite (PDF Download Available)" (in en). https://www.researchgate.net/publication/306828184_Younger_postectonic_monazite_in_the_Pisek_pegmatite.
- ↑ Hrubcová, P.; Środa, P.; Špičák, A.; Guterch, A.; Grad, M.; Keller, G. R.; Brueckl, E.; Thybo, H. (2005-11-01). "Crustal and uppermost mantle structure of the Bohemian Massif based on CELEBRATION 2000 data" (in en). Journal of Geophysical Research: Solid Earth 110 (B11): B11305. doi:10.1029/2004JB003080. ISSN 2156-2202. Bibcode: 2005JGRB..11011305H. http://onlinelibrary.wiley.com/doi/10.1029/2004JB003080/abstract.
- ↑ 1944-, Rajlich, Petr, (2007-01-01). Český kráter. Jihočeské muzeum. ISBN 9788086260808. OCLC 276814811. https://www.worldcat.org/oclc/276814811.
- ↑ 1944-., Rajlich, Petr, (2014-01-01). Vesmírná příhoda v Českém křemeni (a v Českém masivu). Geologie. ISBN 9788026056782. OCLC 883371161. https://www.worldcat.org/oclc/883371161.
- ↑ Mestan, J.; Alvarez Polanco, E. I. (2014-12-01). "Density Variations in Quartz As a Key for Deciphering Impact-Related Ultrasonic Sounding (Rajlich's Hypothesis)?". AGU Fall Meeting Abstracts 11. Bibcode: 2014AGUFMMR11A4310M.
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