Iğneada (Kirklareli) dolaylari üst kretase istifinin stratigrafisi ve fasiyes özellikleri

This study mainly deals with stratigraphic features and facies characteristics of volcano-sedimetary sequence of İğneada region (Kırklareli). In order to achieve this goals 1050 meter thick three stratigraphic sections were measured in the İğneada Formation showing well-exposed outcrops in the Limanköy, Sislioba and Avcılar areas.İğneada Formation unconformably overlies the Mahya Formation. consisting of Jurassic micaschissts and marble lenses and it is approximately 600 m thick.İğneada Formation consists of 15-20 cm thick conglomerates at the bottom levels and it grades to rudist-bearing 10 m thick neritic limestones in the Limanköy area. Rudist fauna consists mainly of radiolitids suggesting an Albian age (probably middle), some benthic foraminifers and algae are also determined. 15-20 m thick, yellow colored sandstones rich-in Orbitolina conformably overlie the neritic limestones and consist of Orbitolina species indicating an Albian age. Orbitolina-bearing sandstones pass upward to 40-50 m thick, yellowish-grey sandstones with thin-shelled bivalvia, planktonic foraminifera are also observed. Upper part of the formation consists alternation of 70-80 m thick, grey pelagic mudstones and 400-420 m thick, volcanic rocks such as andesitic tuffs, basalts, agglomerates and spilitic volcanics and pelagic mudstones. Planktonic foraminifers suggest a Cenomanina-Turonian and probably Coniacian age for the pelagic levels of the formation.The base of İğneada Formation is represented dominantly by clastics around Avcılar and Sislioba areas when compared with that of Limanköy area. 10-15 m thick conglomerates and sandstones gradually pass upward to Orbitolina-bearing sandstones and pelagic mudstone and sandstone alternation and at uppermost part of formation the volcanic rocks are observed.According to field observations and thin section analysis, seven microfacies have been distinguished. These are: conglomerate-litharenite, rudist fragments-bearing packstone-wackestone, Orbitolina-bearing litharenite, carbonate cemented litharenite with thin shell fragments, pelagic mudstone?lithic wackestone, planktonic foraminifera and calcisphere-bearing wackestone and volcanic intarcalated alternation of mudstone and wackestone.The lithologic and sedimentologic features show that the volcano-sedimentary sequence of the Strandja Zone started to develope on the low relief of the carbonate ramp characterizing by the alluvial, fluvial and sea-shore clastics grading to shallow marine limestones and low energy basinal mudstones supported by volcanic rocks