Stratigraphy of the Upper Cretaceous and Paleogene in Yığılca-Bolu (NW Turkey)

Yıl 1986, Cilt: 107 Sayı: 107, 1 - 23, 01.12.1986

Orhan Kaya Atife Dizer İzver Tansel Sacit Özen

Öz

The post-Triassic rocks of the
Yığılca area extend in age from late Santonian/early Campanian to Ypresian or
probably Lutetian, and constitute a marine sequence intervened by submarine and
subaerial unconformities. The sequence is represented primarily by
volcaniclastic sandstone and conglomerate, derived from a provenance of mafic
volcanic rocks, and subordinately by epiclastic sandstone. The Cretaceous and
Paleogene rocks of the Yığılca area have a marked lithic and sequential
similarity to those in the northerly-lying Ereğli area. The Cretaceous is
suggested to have been deposited by the progressive onlap of an apparently
southward transgressing sea. The coeval but differing rocks of the uppermost
Cretaceous and Paleogene in the Yığılca, and southerly-lying Bolu and Mengen
areas, suggests a structural divide to the south of the Yığılca area, formed by
the latest Cretaceous. The totally 200 m thick Cretaceous olistostromal
interval of the Yığılca sequence, which has a 4 m thick correlative in the
Ereğli sequence, has apparently a significant bearing on the stratigraphy of
the so-called «Ankara melange». The arcal structure is characterized by a
southward recumbent syncline whose northern limb is thrusted on the southern.
High-angle faults are suggested to be originally shear fractures related to a
nearly northeast-trending horizontal acute bisector, and later to have acted as
extensional. High-angle faults postdate the thrust, and both are probably
post-Lutetian in age.

Anahtar Kelimeler

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Kaynakça

• Assereto, R., 1972, Notes on the Anisian biostratigraphy of the Gebze Area (Kocaeli Peninsula, Turkey): Z. dtsch. Geol. Ges., 123, 435-444.
• Atabek, S., 1940, Dibektaş manganez madeni hakkında rapor: MTA Rap., 1184, (yayımlanmamış), Ankara.
• Bailey, E.B. ve McCallien, W. J., 1954, Serpentinite lavaş, the Ankara melange and the Anatolian thrust: Transact. R. Soc., Edinburgh, 62, 403-442.
• Batum, İ., 1968, 1: 25 000 ölçekli Adapazarı G26-b3 paftasının jeolojisi: MTA Rap., 4778, (yayımlanmamış), Ankara.
• Blumenthal, M., 1948, Un apperçu de la geologie des chaines nord-anatoliennes entre l'Ova de Bolu et Ie Kızılırmak infcrieur: MTA Yayl., B-13, 265, Ankara.
• Burkan, K. A.; Şahintük, ö. ve Yazman, M., 1982, Ereğli-Kozlu-Yığılca bölgesinin jeolojisi: TPAO Rap., 1537.
• Dizer, A., 1971, La limite Cretace-Tertiaire dans Ie bassin NW de la Turquie: Rev. Micropaleontogique, 14, 43-47.
• Görmüş, S., 1980, Yığılca (Bolu NW) yöresinin jeolojik incelemesi: HÜ, Doktora tezi, 210.
• ——, 1982a Yığılca (Bolu KB) yöresinin stratigrafisi: HÜ, Yerbilimleri Fakültesi Yayl., 9, 91-110.
• , 1982*, Yığılca (Bolu KB) yöresinin tektoniği ve jeolojik evrimi: HÜ, Yerbilimleri Fakültesi Yayl, 9, 133-140.
• Kaya, O., 1973, The Devonian and Lower Carboniferous stratigraphy of the İstinye, Bostancı and Büyükada subareas: Kaya, O., ed., Paleozoic of istanbul, da., EÜFF, Kitaplar Serisi, 40, 1-36.
• , 1982, Ereğli, Yığılca, Bolu kuzeyi ve Mengen alanlarının stratigrafi ve yapı özellikleri: TPAO Rap., 1639.
• ve Dizer, A., 1984», Bolu kuzeyi Üst Kretase ve Paleojen kayalarının stratigrafi ve yapısı: MTA Derg., 97/98, 57-77, Ankara.
• ve , 1984*, Mengen (Bolu) Eosen kömür havzasının stratigrafisi: MTA Derg., 97/98, 123-139, Ankara.
• —; ; Tansel, 1. ve Meriç, E., 1984c, Ereğli (Zonguldak) alanının stratigrafisi: MTA Derg., 99/100, 19-33, Ankara.
• Ketin, 1. ve Gümüş,Ö., 1963, Sinop-Ayancık güneyinin jeolojisi: TPAO Rap., 288.
• Lundegard, P.D. ve Samuels, N.D., 1980, Field classification of f ine-grained Sedimentary rocks: Jour. Sed. Petrology, 50, 781-786.
• Saner, S.; Taner, 1.; Aksoy, Z. ve Siyako, M., 1979, Karabük-Safranbolu bölgesinin jeolojisi: TPAO Rap., 1322, 203.
• Tokay, M., 1952, Karadeniz Ereğlisi-Araplı-Kızıltepe-Alacaağzı bölgesi jeolojisi: MTA Derg., 42/43, 1-35, Ankara.
• Williams, H.; Turner, F.J. ve Gilbert, C.M., 1954, Petrography: W.H. Freeman, 406.