Lithostratigraphy and planktonic foraminifera of the uppermost Cretaceous-Upper Paleocene strata of the Tavas nappe of the Lycian nappes (SW Turkey)

Abstract

The Lycian nappes lying on top of the para-autochthonous metamorphosed Menderes and unmetamorphosed Bey Dağları successions in SW Anatolia belong to the Tauride segment of the Anatolide-Tauride Block. The Tavas nappe is one of several nappe slices of the Lycian nappes and forms structurally the lowermost tectono-stratigraphic unit. The upper part of the Tavas nappe succession is represented by planktonic foraminifera-bearing uppermost Cretaceous cherty micritic limestones and calciturbidites of the Babadağ Formation and Lower Palaeogene micritic limestones and calciclastic rocks of the Faralya Formation in the study area. Lithostratigraphic characteristics and planktonic foraminiferal assemblages of the two formations in the Bozburun hill locality (S of Köyceğiz) are documented for the first time in three stratigraphic sections in this study. The uppermost part of the Babadağ Formation mainly comprises of alternating calciclastic and micritic limestones, which include diverse planktonic foraminiferal assemblages of mainly keeled morphotypes. The presence of Racemiguembelina fructicosa and Abathomphalus mayaroensis within the assemblages indicates a late Maastrichtian age for the uppermost part of the succession. Two sections of the overlying Faralya Formation comprise mainly planktonic foraminifera-bearing laminated micritic limestones, brecciated limestones and mudstones. Planktonic foraminiferal assemblages of the laminated micritic limestones are dominated by keeled Late Palaeocene morphotypes. The occurrence of Morozovella acuta and Globanomalina planoconica at the base of two sections suggests a Thanetian age for the deposits. The boundary between the Babadağ and Faralya formations is characterized by a stratigraphic gap ranging from the latest Maastrichtian to the earliest Selandian. The gap was linked with the first of the three main events, when ophiolite obduction and incorporation of the Köyceğiz Thrust Sheet into the Lycian allochthon occured. Cretaceous limestone clasts and foraminifers within the Thanetian calciclastic rocks of the Faralya Formation could be clues to that exposure and erosion.

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“…2). This region has already been documented in previous studies (GÜL et al, 2013;GÜL, 2015;SARI, 2017) due to its visible exposures in the field; however, the sedimentary textures, structures, and lateral and vertical facies changes have not been previously documented. Based on litho logical variations, sampling was carried out at 12 m intervals for mineralogical, chemical and petrographic analyses.…”

“…The Beydağları Autochthone includes Late TriassicCreta ceous platform carbonates and the LutetianMiocene sediments ( Fig. 3; ERSOY, 1990;ŞENEL et al, 1989ŞENEL et al, , 1994ŞENEL et al, , 1998SARI & ÖZER, 2001;2002;SARI et al, 2004;SARI, 2006;2017;ŞENEL, 2004ŞENEL, , 2007SOYCAN et al, 2015). The core of the southern part of the Menderes Massif contains gneiss and metagabbro at the core; the cover part includes Upper DevonianEarly Eocene am…”

“…They are mainly composed of allochthons with remnants of oceanic crust that encompass diverse deepwater and platform type deposits (DANELIAN et al, 2006;GÖNCÜOĞLU, 2011;MOIX et al, 2013;SARI, 2017). The Lycian Nappes (including deepwater sediments of the Tavas Nappe), have since become a subject of widespread interest for numerous researchers over the last four decades, focusing on the fossil content and local lithological chara cteristic of the units (YILMAZ, 1981;ERAKMAN et al, 1982;ŞENGÖR et al, 1984;OKAY, 1989;ŞENEL et al, 1994;KO ZUR, 1998;COLLINS & ROBERTSON, 1998, 1999ÖZCAN et al, 2012;GÜL et al, 2013;GÜL, 2015;SOYCAN et al, 2015;SARI, 2017). However, determination of the differences of nappe slices, which are thought to be the product of the same environ ment and when separated are mapped under the same nappe name, can provide valuable information about the primaryorigi nal depositional environment.…”

“…This study focuses on the calciturbidites of the Babadağ Forma tion and its lithological features. The Babadağ Formation is com posed mainly of calcilutite, calcisiltite, in some parts calcarenite and rarely calcirudite in its upper parts (ŞENEL, 1997a(ŞENEL, , 1997bGÜL, 2015;SARI, 2017).…”

“…On the Boz burun hill, calciturbidites of the Babadağ Formation overlie the older Tavas Nappe deposits, and are unconformably overlain by the Faralya Formation. The Bozburun hill was previously studied in detail (GÜL et al, 2013;GÜL, 2015;SARI, 2017). They re ported that Bozburun hill is composed of mainly laminated and thinly (25 cm) undulating, bedded calcilutite at the base, lami nated, thin (48 cm) to medium (1025 cm) bedded calcarenite mainly laminated and thinly (25 cm) undulating, bedded calci lutite alternations with chert layers in the middle, while thin (48 cm) to medium (1025 cm) bedded calcarenites medium (1025 cm) to thickly (30100 cm) bedded calcirudites dominate the up permost part of the succession (Fig.…”