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Micropaleontological analysis and facies evolution across the tournaisian-visean boundary in aladağ unit(Central Taurides, Turkey)

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2005
Peynircioğlu, Ali Ahmet
This study aims to enlighten microfacies evolution and micropaleontological properties of the Tournaisian ا Visean boundary in Aladağ Unit (Central Taurides, Turkey). Two sections comprising dark shale and dark limestone alternations, including a fairly dolomitized part towards their top are measured. The microfacies analysis suggests a subtidal depositional environment. Foraminiferal assemblages were distinguished at Section AP and biozonation was documented. The biozonation separates the measured section into three zones, described as A, B and C. Zone A is scarce foraminifera fauna, and mainly contains Earlandia sp. Zone B is defined by appearance of a diversified foraminifera fauna and the first appearance of Lugtonia monilis (Malakhova, 1955) with Eoparastaffella sp. (morphotype 1). Zone C is defined according to the first appearance of Eoparastaffella simplex (Vdovenko, 1964) (morphotype 2) and foraminifers Laxaendothyra ex. gr. laxa. Tournaisian ا Visean boundary is defined at the 60th sample, due to appearance of Eoparastaffella simplex (Vdovenko, 1964) (morphotype 2). Seven microfacies types in section AP, and six microfacies types in section PA are identified and, the intensely sampled part of the measured section AP is separated into 13 shallowing upward meter-scale cycles. These cycles, showing subtidal character are detected by both repetitions of microfacies and changes in abundance of foraminifers. A contrasting evaluation of the Tournaisian ا Visean boundary of Taurides with Guangxi, South China and Dinant, Belgium is presented. The Chinese stratotype contains a diverse, more complete fauna of Tournaisian - Visean foraminifera, while the Belgium and Turkish sections are scarcer and most probably facies controlled.