Lithostratigraphy of the Upper Cretaceous Series in a part of the Krayshte area (Southwest Bulgaria)

Pages: 
pp. 69-80
Sofia University “St. Kliment Ohridsky”, 1000 Sofia, 15 Tsar Osvoboditel Blvd.
Geological Institute Bulgarian Academy of Sciences, 1113 Sofia, 24 G. Bonchev Str.
Geological Institute Bulgarian Academy of Sciences, 1113 Sofia, 24 G. Bonchev Str.
Ministry of Environment and Water, 1000 Sofia, 22 Maria Louisa Blvd.
Abstract: 

The Upper Cretaceous sediments in Krayshte area are reported to have a wider distribution than previously considered. They are dated using calcareous nannofossils, proving the presence of different parts of the Campanian Stage.
   Four new formal lithostratigraphic units are introduced and characterized. The Gorna Koznitsa Formation consists of coarse siliciclastic rocks and is probably of Early Campanian Age. The Gorno Gabreshevo Fm. is represented by rhythmic turbidites of Early to Late Campanian Age. The Uglyartsi Fm. is dominated by fine grained sediments – marls, finely laminated claystones and clayey limestones. Its age is Campanian, too. These three units are widespread in the area. The last unit, Shabanitsa Fm., is locally developed in the eastern part of the area. It is built up by loose siliciclastic and mixed hypo-rocks, including non-marine sediments –oncoid limestones and stromatolites of Late Campanian Age.
   The Upper Cretaceous sediments were deposited most probably in a tectonically controlled asymmetric basin (Babushnitsa-Fucha basin – Zagorchev et al., 2006). The sediments in the eastern parts of the basin exhibit the greatest variety. The coarse clastic sequences cover transgressively over the northern board of the basin, and are covered by predominantly marly deposits. Westwards, they are gradually replaced by marly and carbonate sediments that probably pass to the north into the limestone sequences typical for the western parts of the basin on the territory of Serbia.

М. Иванов, К. Стойкова, И. Загорчев, Е. Горанов. Литостратиграфия верхнемеловой серии в части Краиштенской области (Юго-Западная Болгария). Установлено, что верхнемеловые осадочные породы в области Краиште распространены гораздо шире, чем считалось до сих пор. Их возраст определен по известковым нанофоссилиям, которые доказали принадлежность пород к разным отделам кампанского яруса. 
   Приведена характеристика четырех новых официальных литостратиграфических единиц. Горнокозницская свита представлена грубыми силикокластическими породами. Ее вероятный возраст раннекампанский. Горногабрешевская свита сложена ритмическими турбидитами ранне-позднекампанского возраста. В Углярской свите преобладают тонкозернистые породы: мергели, тонколаминированные глинистые сланцы и глинистые известняки. Их возраст тоже кампанский. Все три перечисленные свиты широко представлены в исследованной области. Четвертая (Шабаницская) свита развита ограничено в ее восточной части. Она сложена нелитифицированными силикокластическими и смешаными гипо-породами, в том числе и неморскими отложениями: онкоидными известняками и строматолитовыми образованиями позднекампанского возраста. 
    Накопление верхнемеловых осадочных пород происходило по всей вероятности в тектонически обусловленном ассиметрическом бассейне (бассейн Бабушница – Фуча – Zagorchev et al., 2006). В его восточной части шло отложение очень разнообразных пород. Северная окраина бассейна перекрыта трансгрессивно грубокластическими последовательностями. На них залегают преимущественно морские отложения, которые в западном направлении постепенно замещаются мергельными и карбонатными породами, видимо переходящими к северу в известняковую последовательность, типичную для западных частей верхнемелового бассейна на территории Сербии.

Keywords: 

lithostratigraphy, Upper Cretaceous, Campanian, calcareous nannofossils, Krayshte, SW 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