Over 18,000 joint orientations were measured from a spectrum of lithologies of various ages at natural exposures in the Central Kyzyl Kum region. For each exposure, we plotted joint orientation diagrams and identified local joint systems. Orientations of these systems were established from both i density maxima of poles to joints on stereograms and ii cluster analysis. Tilt-corrected data from coeval strata integrated over all the measurement localities were used to identify regional joint directions and their relative development. In Paleozoic sedimentary rocks these directions are, overall, close to fault and fold trends in structures related to pre-Paleozoic, Caledonian, and Hercynian evolutionary stages. However, regional joint systems display certain changes in their direction and development depending on rock age. In Cretaceous deposits, regional joint directions are chiefly inherited from those in Paleozoic strata. Our study of time-dependent changes in regional jointing characteristics proves that, as the region kept developing, the primary jointing became overprinted by additional random joints and tectonic joint systems. Our previous attempt to reconstruct paleostresses in the study region from joints in sedimentary rocks yielded results closely similar to fold trend data.
joint orientation, Central Kyzyl Kum, cluster analysis, paleostress.
1. Aivazian, Classification and Decrease in Dimensionality, 1989.
2. Akhmedzhanov, Uzbek. Geol. Zhurnal, v. 2, 1970.
3. Belousov, Principal Issues of Geotectonics, 1962.
4. Belousov, Izv. Akad. Nauk SSSR, Fiz. Zemli, no. 2, 1990.
5. Belousov, Methods for Processing and Results of Interpretation of Jointing, 1994.
6. Belousov, Sources and Impact of Destructive Seismic Shocks, Voprosy Inzhenernoi Seismologii, 31, 1990.
7. Belousov, Textures and Microstructures, v. 25, 1996.
8. Belousov, Parting of the Earth's Crust and Paleostresses in Seismoactive and Petroliferous Regions, 1997.
9. Bunge, Texture Analysis in Material Science, 1982.
10. Chediya, Southern Central Asia during the Recent Mountain Building Epoch, Book 1, 1971.
11. Chediya, Southern Central Asia during the Recent Mountain Building Epoch, Book 2, 1972.
12. Chediya, Morphostructures and Neotectonics in Tien Shan, 1986.
13. Chernyshev, Jointing in Rocks, 1983.
14. Cowin, Mech. Mater., v. 4, 1985., doi:https://doi.org/10.1016/0167-66368590012-2
15. Geologic map..., Geologic map of Eurasia, scale 1:6,000,000, 1954.
16. Geologic map..., Geologic map of Middle Asia and adjacent areas, scale 1:500,000, 1964.
17. Geology..., Geology of the USSR, Vol. 23, Book 1, Book 2, 1972.
18. Grachev, Fiz. Zemli, no. 8, 1993.
19. Grachev, Fiz. Zemli, v. 1, 2000.
20. Graizer, Detailed Seismologic Engineering Surveys, Voprosy Inzhenernoi Seismologii, 27, 1986.
21. Hammah, Int. J. Rock Mech. Min. Sci., v. 35, 1998., doi:https://doi.org/10.1016/S0148-90629800011-4
22. Hancock, J. Struct. Geol., v. 7, no. 3/4, 1985., doi:https://doi.org/10.1016/0191-81418590048-3
23. Ibragimov, Neotectonic Structures of the Central Kyzyl Kum Region and Their Seismotectonic Characteristics, 1973.
24. Kawamoto, Int. J. Numer. Anal. Math. Geomech., v. 12, 1988., doi:https://doi.org/10.1002/nag.1610120102
25. Khain, Regional Geotectonics, Non-Alpine Europe and Western Asia, 1977.
26. Krestnikov, Quaternary Tectonics of Pamir and Tien Shan, 1979.
27. Krestnikov, Izv. Akad. Nauk SSSR, Fiz. Zemli, no. 9, 1980.
28. Lee, Engineering Geology, v. 39, 1995., doi:https://doi.org/10.1016/0013-79529400064-9
29. Mahtab, Issues in Rock Mechanics, Proc. 22nd Symp. Rock Mechanics, Berkeley, edited by R. E. Goodman and F. E. Heuze, 1982.
30. Oda, Water Resources Research, v. 22, no. 13, 1986.
31. Permyakov, Tectonic Jointing on the Russian Craton, 1949.
32. Petrushevsky, The Urals-Siberia Post-Hercynian Craton and Tien Shan, 1955.
33. Pollard, Geol. Soc. Amer. Bull., v. 100, 1988., doi:https://doi.org/10.1130/0016-76061988100lt;1181:PIUJOTgt;2.3.CO;2
34. Rezvoi, Vestn. Lvov. Univ., Ser. Geol., v. 1, 1962.
35. Salganik, Mekh. Tverd. Tela, no. 4, 1973.
36. Savelova, Representations of the Group SU2 and Their Applications, 1996.
37. Shanley, J. Math. Geol., v. 8, no. 3, 1976., doi:https://doi.org/10.1007/BF01039681
38. Shultz, Analysis of Neotectonics and Relief in Tien Shan, 1948.
39. Shultz, Tr. Laboratorii Aerometodov, v. 4, 1955.
40. Shultz, Sov. Geol., no. 5, 1962.
41. Swoboda, Computers and Geotechniques, v. 22, no. 3/4, 1998., doi:https://doi.org/10.1016/S0266-352X9800009-3
42. Wenck, Fiz Zemli, no. 6, 1993.
43. Yuriev, Tectonic Movements and Neotectonic Structures in the Earth's Crust, 1967.
