Callovian to Lower Cretaceous pelagic carbonates in the West Balkan Mountains (Komshtitsa and Barlya sections): integrated biostratigraphy and microfacies

Pages: 
pp. 81-89
Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
Abstract: 

The Jurassic System in the West Balkan Mountains attracted the attention of the first scholars of geology and stratigraphy in Bulgaria F. Toula and V. Zlatarski more than 100 years ago. The intense field, palaeontological and stratigraphical studies of the Upper Jurassic and Lower Cretaceous pelagic carbonates in the Izdremets Syncline led to the lithostratigraphic subdivision and establishment of all stages from the Callovian to the Hauterivian as a relust of publications of I. Sapunov, I. Nachev, T. Nikolon and G. Mandov in the 60s and 70s of the last century. An integrated micropalaeontological zonation of the Tithonian, Berriasian and Valanginian was elaborated by I. Lakova, K. Stoykova and D. Ivanova. Recently, P. Tchoumatchenco divided the sections at Komshtitsa and Barlya into second- and third-order sequences.
   The subject of this paper is a synthesis of the existing stratigraphic knowledge of the Callovian to Valanginian pelagic carbonate succession at the sections of Komshtitsa and Barlya in the West Balkan tectonic unit, as well as a correlation with new micropalaeontological and microfacial results. A zonation on calcareous dinocysts for the Upper Jurassic is here presented and correlated to the ammonite zones in the Yavorets, Gintsi and Glozhene Formations. The used biostratigraphical criteria of determination of the stage boundaries (Callovian to Valanginian) are discussed. Six successive microfacies are determined and described: filamentous, Globuligerina-radiolarian, Saccocoma, Globochaete, calpionellid and spicule.

И. Лакова, П. Чумаченко, Д. Иванова, Е. Колева-Рекалова. Объединенная биостратиграфия и микрофации кэлловейских-нижнемеловых пелагических карбонатов Западнобалканской единицы (разрезы Комштица и Бырля). Юрская система в западной части Балканских гор привлекла внимание первых исследователей болгарской геологии и стратиграфии более 100 лет тому назад. В результате интенсивных полевых, палеонтологических и биостратиграфических исследований осуществилось литостратиграфическое и биостратиграфическое расчленение верхнеюрских-нижнемеловых пелагических карбонатных пород в Издремецской синклинали. Благодаря исследованиям И. Сапунова, И. Начева, Т. Николова, Г. Мандова и других специалистов в 60-ых и 70-ых годах 20-ого века в регионе были установлены все ярусы - с кэлловейского до готеривского. Объединенное микропалеонтологическое зонирование титонского, берриассового и валанжинского ярусов является результатом исследований И. Лаковой, К. Стойковой и Д. Ивановой. В последнее время П. Чумаченко расчленил разрезы Комштица и Бырля на секвенции второго и третьего порядка. В предлагаемой работе представлена синтетическая стратиграфическая картина кэлловейской-валанжинской карбонатной последавотельности в разрезах Комштица и Бырля Западнобалканской тектонической единицы. Картина дополнена микропалеонтологическими данными и данными о микрофациальной принадлежности. Зоны, выделенные в верхнеюрской серии по диноцистам, скоррелированы с аммонитными зонами Яворецской, Гинской и Гложенской свит. В работе обсуждаются биостратиграфические критерии, по которым проведены нижние границы ярусов (с кэлловейского до валанжинского). Выделено шесть последовательных микрофаций: филаментная, Globigerina-радиолярийная, Saccocoma, Gobochaete, калпионельная и спикульная.

Keywords: 

Upper Jurassic, Lower Cretaceous, West Balkan, biostratigraphy, microfacies

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