The Maraº region of Turkey includes the Anatolian-Arabian-African triple junction. The African-Arabian margin is marked by left-lateral transtension along the Dead Sea (Kara Su) rift. Motion on the Anatolian-Arabian boundary is partitioned between the left-lateral East Anatolian fault and a fold-thrust belt termed the Engizek zone, equivalent to the Bitlis suture further east. The African-Anatolian boundary lies along the Cyprus-Misis-Andirin trend and is expressed near the triple junction as the Aslantaº-Iskenderun zone, now undergoing slow left-lateral transtension. The Neogene evolution of these boundaries is largely recorded in the stratigraphy and structure of the basins that lie along the Anatolian-Arabian (Lice basin) and Anatolian-African (Aslantaº-Iskenderun basin) boundaries. These basins appear to have developed in the early Miocene along major strike-slip zones. Large half graben in the pre-Neogene 'basement' of the western (Misis-Andirin block) developed contemporaneously with motion on the Anatolian-African boundary. These extensional features evolved subsequent to the intense shattering of the Mesozoic carbonate sequence in the Misis-Andirin block and its mixing with panels of deep water Palaeogene strata to form an extensionally disrupted assemblage. Transpression and conversion of both Anatolian-African and Anatolian-Arabian boundaries to fold-thrust belts occurred in the late Miocene. Transpression continues along the Anatolian-Arabian boundary but transtension has recurred along the Anatolian-African boundary since the Pliocene.

We present a new survey of several Palaeozoic sections in both the Taurus range and the Border Folds that documents typical glacial features including a glacial pavement and striated dropstones (Halevikdere Formation) and demonstrates the former presence of an ice sheet in southern and south-eastern Turkey. Evidence for the late Ashgill (Hirnantian) age of this episode is provided by macro- and microfossils found within the glacial formation. The extension of ice-related deposits into the northernmost part of the Arabian Platform (Mardin region) implies a much wider distribution of the Ordovician ice sheet than was previously believed, and strongly suggests that southern Turkey lay close to Egypt during the Lower Palaeozoic

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Revision of the lithostratigraphy of Ordovician deposits in southern and southeastern Turkey led to a re-evaluation of the age assignments of formations identified in the subsurface and at outcrop. Previous datings were based on macrofauna (mainly trilobites and graptolites). The present paper focuses exclusively on organic-walled microfossils (chitinozoans and acritarchs), which provide numerous chronostratigraphical improvements, especially in successions barren or poor in macrofossils. Close to 200 samples were collected in the Taurus chain (i.e. from Kemer, Seydisehir, Ovacik, Kozan, to Sariz regions in southern Turkey) and in the Border Folds (Mardin and Hakkari regions), usually regarded as part of the Arabian Plate in palaeogeographical reconstructions. Many samples are productive and yield chitinozoans and/or acritarchs of extremely variable preservation, depending on their geographical and geological location. In the Taurus chain, the material is "coalified" and frequently fragmented whereas, in the Border Folds, maturation of the organic matter is much lower and preservation of the microfossils is good to excellent. Several Ordovician chitinozoan biozones (northern Gondwana zonation) as well as diagnostic acritarch assemblages are identified in southern and southeastern Turkey. These Ordovician formations are assigned here to the new global stages of the Ordovician chronostratigraphical scale. The Seydisehir (upper part), Sobova, and Kilgen Lake (lower part) formations are referred to the Darriwilian. The Kilgen Lake (upper part), Sort Tepe, and Bedinan formations are attributed to the Sandbian and to the Katian, and the Halevikdere Formation (glacio-marine part) is assigned to the Hirnantian. Reworking of Early Ordovician acritarchs is documented in preglacial and in glacial Late Ordovician deposits. They indicate that active erosive processes occurred during the Middle and Late Ordovician sedimentation. The organic-walled microfossils recorded in the Ordovician of south and southeastern Turkey belong to the northern Gondwana realm. Interestingly however, some Baltoscandian influences are noted in the Border Folds during Early Late Ordovician. Résumé Une révision de la lithostratigraphie des dépôts ordoviciens du sud et du sud-est de la Turquie a conduit à une réévaluation des attributions stratigraphiques des diverses formations reconnues, à la fois à l'affleurement et en forage. Des datations étaient déjà fournies par la macrofaune (trilobites et graptolites notamment). Le présent article est consacré exclusivement aux microfossiles organiques (chitinozoaires, acritarches) qui apportent de nombreuses précisions d'ordre chronostratigraphique, notamment dans des séquences pauvres ou dépourvues en macrofossiles. Près de 200 échantillons ont été prélevés dans la chaîne du Taurus (régions de Kemer, Seydisehir, Ovacik, Kozan, Sariz, dans la Turquie méridionale) et aux confins sud-est de la Turquie, dans les régions de Mardin et de Hakkari (« Border Folds »), généralement intégrées à la Plaque Arabe dans le...

A number of Late Cretaceous ophiolitic bodies are located between the metamorphic massifs of the southeast Anatolian orogenic system. One of them, the Göksun ophiolite (northern Kahramanmaraş), which crops out in a tectonic window bounded by the Malatya metamorphic units on both the north and south, is located in the EW-trending nappe zone of the southeast Anatolian orogenic belt between Göksun and Afşin (northern Kahramanmaraş). It consists of ultramafic–mafic cumulates, isotropic gabbro, a sheeted dyke complex, plagiogranite, volcanic rocks and associated volcanosedimentary units. The ophiolitic rocks and the tectonically overlying Malatya–Keban metamorphic units were intruded by syn-collisional granitoids (∼ 85 Ma). The volcanic units are characterized by a wide spectrum of rocks ranging in composition from basalt to rhyolite. The sheeted dykes consist of diabase and microdiorite, whereas the isotropic gabbros consist of gabbro, diorite and quartzdiorite. The magmatic rocks in the Göksun ophiolite are part of a co-magmatic differentiated series of subalkaline tholeiites. Selective enrichment of some LIL elements (Rb, Ba, K, Sr and Th) and depletion of the HFS elements (Nb, Ta, Ti, Zr) relative to N-MORB are the main features of the upper crustal rocks. The presence of negative anomalies for Ta, Nb, Ti, the ratios of selected trace elements (Nb/Th, Th/Yb, Ta/Yb) and normalized REE patterns all are indicative of a subduction-related environment. All the geochemical evidence both from the volcanic rocks and the deeper levels (sheeted dykes and isotropic gabbro) show that the Göksun ophiolite formed during the mature stage of a suprasubduction zone (SSZ) tectonic setting in the southern branch of the Neotethyan ocean between the Malatya–Keban platform to the north and the Arabian platform to the south during Late Cretaceous times. Geological, geochronological and petrological data on the Göksun ophiolite and the Baskil magmatic arc suggest that there were two subduction zones, the first one dipping beneath the Malatya–Keban platform, generating the Baskil magmatic arc and the second one further south within the ocean basin, generating the Göksun ophiolite in a suprasubduction zone environment.