The Rhodope Zone as a primary sediment source of the southern Thrace basin (NE Greece and NW Turkey): evidence from detrital heavy minerals and implications for central-eastern Mediterranean palaeogeography

Abstract

a common origin of tectonic units exposed in NW Turkey (Biga Peninsula) with those of NE Greece and SE Bulgaria (Rhodope region). The entire region displays (1) common extensional signatures, consisting of comparable granitoid intrusion ages, and a NE-SW sense of shear (2) matching zircon age populations between the metapelitic and metamafic rocks of the Circum-Rhodope Belt (NE Greece) and those of the Çamlica-Kemer complex and Çetmi mélange exposed in NW Turkey. Detrital heavy mineral abundances from Eocene-Oligocene sandstones of the southern Thrace basin demonstrate the influence of two main sediment sources mostly of ultramafic/ophiolitic and low-to medium-grade metamorphic lithologies, plus a third, volcanic source limited to the late Eocene-Oligocene. Detrital Cr-spinel chemistry is used to understand the origin of the ultramafic material and to discriminate the numerous ultramafic sources exposed in the region. Compositional and stratigraphic data indicate a major influence of the metapelitic source in the eastern part (Gallipoli Peninsula) during the initial stages of sedimentation with increasing contributions from metamafic sources through time. On the other hand, the western and more external part of the southern Thrace margin (Gökçeada, Samothraki and Limnos) displays compositional signatures according to a mixed provenance from the metapelitic and metamafic sources of the Circum-Rhodope Belt (Çamlıca-Kemer complex and Çetmi mélange). Tectonic restoration and compositional signatures provide constraints on the Palaeogene palaeogeography of this sector of the central-eastern Mediterranean region.Abstract Detrital heavy mineral analysis coupled with a regional geological review provide key elements to reevaluate the distribution of the Rhodope metamorphic zone (SE Europe) in the region and its role in determining the evolution of the Thrace basin. We focus on the Eocene-Oligocene sedimentary successions exposed in the southern Thrace basin margin to determine the dispersal pathways of eroded crustal elements, of both oceanic and continental origins, as well as their different contributions through time. Lithological aspects and tectonic data coupled with geochemistry and geochronology of metamorphic terranes exposed in the area point to Electronic supplementary material The online version of this article (

Drainage and environmental evolution across the Permo–Triassic boundary in the south‐east Germanic Basin (north‐east Bavaria)

“…The Upper Rotliegend metamorphic index (MI 277−395) (Fig. 11E) indicates erosion of mixed low‐grade and high‐grade metamorphic rocks (Garzanti & Vezzoli, 2003; Caracciolo et al ., 2015). Ediacaran low‐grade metasedimentary rocks belong to the Saxo–Thuringian basement underlying the sedimentary succession of Obernsees‐1 (Wall et al ., 2019).…”

Thrace Basin—An Oligocene Clastic Basin Formed During the Exhumation of the Rhodope Complex

“…These new data show that the bulk of subsidence in the Thrace Basin occurred not during the Eocene, as generally assumed, but in the early Oligocene (34–28 Ma) and was coeval with the exhumation of the Rhodope Complex. New detrital zircon ages from the Oligocene sandstones, and published paleocurrent and petrographic data (Caracciolo et al., 2015; Cavazza et al., 2013; d’Atri et al., 2012) also indicate the Rhodope Complex as the major sediment source.…”

“…Paleocurrent data from the Thrace Basin indicate eastward flow in the western and central parts and northward flow in the south (Figure 2, Caracciolo et al, 2015;Cavazza et al, 2013;d'Atri et al, 2012;Maravelis et al, 2016;Şenol, 1980). Sandstones from the western and central parts of the Thrace Basin are characterized by plutonic-metamorphic detritus with a likely source in the Rhodope Complex, whereas those from the southern part have an additional ophiolite and penecontemporaneous volcanic detrital component and indicate a source in the south (Caracciolo et al, 2015;Cavazza et al, 2013;d'Atri et al, 2012;Maravelis et al, 2016;Okay et al, 2010). To further constrain the provenance of the sediments of the Thrace Basin, we analyzed detrital zircons from three sandstone samples from the Ganos Mountain, one each from the Gaziköy, Keşan, and Mezardere formations (Figures 4 and 6).…”

Provenance and tectonic setting of Carboniferous–Triassic sandstones from the Karaburun Peninsula, western Turkey: A multi-method approach with implications for the Palaeotethys evolution

“…Chrome spinel is a very stable, accessory mineral associated with mafic and ultramafic igneous rocks and is widely used as provenance indicator in studies of sedimentary rocks (e.g., Poper and Faupl, 1988;Cookenboo et al, 1997;Lužar-Oberiter et al, 2009;Caracciolo et al, 2015). Its chemical composition is controlled by several factors, as the behavior of the main components Cr, Mg and Al is different during fractional crystallization or partial melting.…”