Cyclostratigraphy of the Jurassic rocks in Western Bulgaria

Pages: 
pp. 123-126
Geological Institute, BAS, Acad. G. Bonchev Street Bl. 24, 1113 Sofia, Bulgaria
Abstract: 

The aim of this research is to check if the method used by Fisher (1991) can gave results, reflecting approximately the orbital cycles in the Milankovitch band. I used the following data: (1) thickness of the study interval – it was necessary to make new redescriptions of some important sections; (2) continuity (in Ma) of the study interval – it is referred to the Time scale used by Hardenbol et al. (1998, Charts 5, 7); (3) speed of sedimentation in Bubnoff units (Ma/meters); (4) number of couplets in the study interval; (5) thickness of a single couplets; (6) continuity (periodicity) of a couplet = average thickness of a couplet divided by the Bubnoff
units. In most of the cases the obtained periodicity of the couplets are closed to or coincide with the theoretical orbital cycles of the Milankovitch band: Eccentricity – El = 98 Ka; E2 =126 Ka (EI, 2 = 98-126 Ka); Obliquity = 41 Ka; Precession – PI = 19 Ka; P2 = 23 Ka (P = 19-23 Ka) (after Fischer, 1991, p.48).
   I studied the limestone/marl couplets in the sections, where existed a good biostratigraphical control, based on ammonites (Sapunov, 1976a, b; 1977a, b; Sapunov in Sapunov et al., 1985, 1988, etc.), brachiopods (Tchoumatchenco, 1977) or calpionellids and precalpionellids (Lakova, 1993, Lakova et al., 1999, etc.). Here are shown the results obtained from the rocks of the Lower Jurassic – sections Berende Izvor, Komsh titsa; Aalenian-Lower Bathonian – section Zhablyano; Bathonian-Lower Callovian – section Koritarska Reka - Dolna Riksa; Callovian-Tithonian – sections Komshtitsa, Gorno Belotintsi, Belogradchik- Railway station Oreshets.

VOLUME 32 (2-4)/December 2002 110th Anniversary of Acad. Prof. Strashimir Dimitrov; XVII Congress of the Carpathian-Balkan Geological Association

Geologica Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev St., bl. 24, 1113 Sofia, Bulgaria

Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Akad. G. Bonchev Str., block 24
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Akad. G. Bonchev Str., block 24
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Akad. G. Bonchev Str., block 24
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Akad. G. Bonchev Str., block 24
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Akad. G. Bonchev Str., block 24
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Akad. G. Bonchev Str., block 24
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Akad. G. Bonchev Str., block 24

Geological Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev str. Bl. 24

Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia

Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia

Geological Institute, Bulgarian Academy of Sciences,Sofia 1113, Bulgaria, Acad. G. Bonchev str, bl. 24
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Geological Institute, Bulgarian Academy of Sciences,Sofia 1113, Bulgaria, Acad. G. Bonchev str, bl. 24
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Earth Science Section of the Uviversity of Geneva, 13, rue des Maraîchers, 1211 Geneva 4, Switzerland
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Earth Science Section of the Uviversity of Geneva, 13, rue des Maraîchers, 1211 Geneva 4, Switzerland

Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria

Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria

Geological Institute BAS, Acad. G. Bonchev Str., Bl. 24 1113 Sofia, Bulgaria

Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
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Sofia University "Sv. Kliment Ohridski", 1504 Sofia, Bulgaria

Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia
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Sofia University "Sv. Kliment Ohridski", Tsar Osvobodilel Blvd, 15, 1000 Sofia
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia

Geological institute, Bulgarian Academy of Sciences, 1113, Sofia, Bulgaria
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Geological institute, Bulgarian Academy of Sciences, 1113, Sofia, Bulgaria
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Geological institute, Bulgarian Academy of Sciences, 1113, Sofia, Bulgaria
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University of Mining and Geology "Sv. Ivan Rilski", 1700, Sofia

Geological institute, Bulgarian Academy of Sciences, 1113, Sofia, Bulgaria

Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia
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Institute of Geochemistry, Siberian branch of the Russian Academy of Sciences, P.O.B. 4019, 664033 Irkutsk
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia

Geological Institute, Bulgarian Academy of Sciences, Sofia, 1113
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Geological Institute, Bulgarian Academy of Sciences, Sofia, 1113
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Geological Institute, Bulgarian Academy of Sciences, Sofia, 1113
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Geological Institute, Bulgarian Academy of Sciences, Sofia, 1113
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Geological Institute, Bulgarian Academy of Sciences, Sofia, 1113
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Geological Institute, Bulgarian Academy of Sciences, Sofia, 1113

Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia

Geological Institute, Bulgarian Academy of Sciences, Sofia, 1113

Geological Institute, Bulgarian Academy of Sciences

Geological Institute, BAS, Acad. G. Bonchev Street Bl. 24, 1113 Sofia, Bulgaria

Geological Institute of BAS, 24 Acad. G. Bonchev Sir., BG - 1113 Sofia
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Geological Institute of BAS, 24 Acad. G. Bonchev Sir., BG - 1113 Sofia
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Geological Institute of BAS, 24 Acad. G. Bonchev Sir., BG - 1113 Sofia

Geological Institute at the Bulgarian Academy of Sciences, Acad. G. Bonchev Str., 1113 Sofia, Bulgaria
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Geological Institute at the Bulgarian Academy of Sciences, Acad. G. Bonchev Str., 1113 Sofia, Bulgaria
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Geological Institute at the Bulgarian Academy of Sciences, Acad. G. Bonchev Str., 1113 Sofia, Bulgaria

University of Mining and Geology, Studentski grad, Sofia, 1100, Bulgaria
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Geological Institute of Romania, Caransebes Str. No 1, Bucharest, RO-78344, Romania
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University of Belgrade, Dusina 7, Belgrad, 11000, Yugoslavia
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Geological Institute of Romania, Caransebes Str. No 1, Bucharest, RO-78344, Romania

Geological Institute at Bulgarian Academy of Sciences, Sofia 1113

Sofia University "Sv. Kl. Ohridski", Department of Geology and Palaeontology, 1504 Sofia