Documentation and correlation of transgressive-regressive cycles from three Lower-Middle Jurassic successions of the Western Balkan Mts, Bulgaria

Pages: 
pp. 91-96
Geological Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 24, 1113 Sofia, Bulgaria
Geological Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 24, 1113 Sofia, Bulgaria
Geological Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 24, 1113 Sofia, Bulgaria
Abstract: 

The transgressive-regressive character and cyclic patterns of the European Jurassic rocks are topics of long-standing interest and debates. As a contrast, in Bulgarian geological literature there is a small number of publications concerning sequence stratigraphy and transgressive- regressive cyclicity of the Jurassic sediments. The main objective of the present study is to document the transgressive-regressive cyclic recurrence of three Lower-Middle Jurassic sections, exposed near the villages of Beledie Han and Breze (Western Balkan, Bulgaria). Fore thirdorder coarsening and shallowing upward transgressive-regressive cycles are recognized on the base of detailed sedimentlogical investigations and dated by precise ammonite zonation which is supplemented by foraminiferal data. It is evidenced that these depositional cycles build up the regressive phase (numbered R6, in accordance with other European basins) of a second order transgressive-regressive facies cycle. This investigation of cyclic character of the studied sections shows that sedimentation during the Toarcian and Early-Mid Aalenian time was formed under conditions of gradual regression of the sea basin.

Е. Колева-Рекалова, Л. Методиев, Д. Иванова. Описание и корреляция трансгрессивных- регрессивных циклов в трех нижне-среднеюрских последовательностях в Западном Балкане, Болгария. Трансгрессивно-регрессивный характер и циклические параметры европейских
юрских пород являются предметом продолжительного интереса и обсуждения, но в болгарской геологической литературе можно найти только незначительное число работ, посвященных секвентной стратиграфии и трансгрессивно-регрессивной цикличности юрских осадочных пород. Основная цель — настощей работы отстроить трансгрессивно-регрессивную циклическую модель трех нижне-среднеюрских разрезов, обнаженных в окрестностях сел Беледие хан и Брезе (Западные Балканы, Болгария). Проведены детальные седиментологические исследования. Выделены аммонитные зоны и получены данные о содержании фораминифер. На основании этой информации вверх по юрскому разрезу выявлено четыре трансгерссивно-регрессивных цикла третьего порядка. Установлено, что депозиционные циклы осадконакопления являются составными частями регрессивной фазы трансгрессивно-регрессивного цикла второго порядка. Эта фаза описана как фаза R6 в согласии с обозначениями, принятыми для других европейских бассейнов. Установленный циклический характер в исследованных разрезах показывает, что осадконакопление в тоарское и ранне-среднеааленское время протекало в условиях постепенной регрессии морского бассейна.

Keywords: 

transgressive-regressive (T-R) cycles, Lower-Middle Jurassic, Western Balkan Mts, Bulgaria

VOLUME 36 (3-4)/December 2007

Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria, G. Bonchev Str., Block 24
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria, G. Bonchev Str., Block 24
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria, G. Bonchev Str., Block 24
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria, G. Bonchev Str., Block 24
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria, G. Bonchev Str., Block 24
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria, G. Bonchev Str., Block 24
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria, G. Bonchev Str., Block 24
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria, G. Bonchev Str., Block 24

Geological Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev str., bl. 24, 1113 Sofia, Bulgaria
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Geological Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev str., bl. 24, 1113 Sofia, Bulgaria

Geological Institute, Bulgarian Academy of Sciences, Bulgaria, 1113 Sofia, Acad. G. Bonchev Str., Bl. 24

Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Acad. G. Bonchev St., Bl. 24
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Acad. G. Bonchev St., Bl. 24

Geological Institute of the Bulgarian Academy of Sciences, 1113 Sofia, Acad. G. Bonchev St., 24

Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia
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Instituto Andaluz de Ciencias de la Tierra, CSIC, Granada, Spain
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University of Granada, Granada, Spain
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia
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University of Granada, Granada, Spain
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia

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

Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia
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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 Scienses, 1113 Sofia, 24 G. Bonchev Str.
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Geological Institute, Bulgarian academy of Scienses, 1113 Sofia, 24 G. Bonchev Str.

Sofia University “St. Kliment Ohridsky”, 1000 Sofia, 15 Tsar Osvoboditel Blvd.
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Geological Institute Bulgarian Academy of Sciences, 1113 Sofia, 24 G. Bonchev Str.
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Geological Institute Bulgarian Academy of Sciences, 1113 Sofia, 24 G. Bonchev Str.
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Ministry of Environment and Water, 1000 Sofia, 22 Maria Louisa Blvd.

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

Geological Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 24, 1113 Sofia, Bulgaria
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Geological Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 24, 1113 Sofia, Bulgaria
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Geological Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 24, 1113 Sofia, Bulgaria

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

Bulgarian Academy of Sciences, Geological Institute, Acad. G. Bonchev St. Bl. 24, 1113 Sofia, Bulgaria
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Middle East Technical University, Department of Geological Engineering, 06531 Ankara, Turkey
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General Directorate of Mineral Research and Exploration, Department of Geological Research, 06520 Ankara, Turkey
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General Directorate of Mineral Research and Exploration, Department of Geological Research, 06520 Ankara, Turkey

Geophysical 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
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Geological Institute, Bulgarian Academy of Sciences
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Geological Institute, Bulgarian Academy of Sciences