Palaeozoic-Recent geological development and uplift of the Amanos Mountains (S Turkey) in the critically located northwesternmost corner of the Arabian continent

<p>We have carried out a several-year-long study of the Amanos Mountains, on the basis of which we present new sedimentary and structural evidence, which we combine with existing data, to produce the first comprehensive synthesis in the regional geological setting. The ca. N-S-trending Amanos Mountains are located at the northwesternmost edge of the Arabian plate, near the intersection of the African and Eurasian plates. Mixed siliciclastic-carbonate sediments accumulated on the north-Gondwana margin during the Palaeozoic. Triassic rift-related sedimentation was followed by platform carbonate deposition during Jurassic-Cretaceous. Late Cretaceous was characterised by platform collapse and southward emplacement of melanges and a supra-subduction zone ophiolite. Latest Cretaceous transgressive shallow-water carbonates gave way to deeper-water deposits during Palaeocene-Eocene. Eocene southward compression, reflecting initial collision, resulted in open folding, reverse faulting and duplexing. Fluvial, lagoonal and shallow-marine carbonates accumulated during Late Oligocene(?)-Early Miocene, associated with basaltic magmatism. Intensifying collision during Mid-Miocene initiated a foreland basin that then infilled with deep-water siliciclastic gravity flows. Late Miocene-Early Pliocene compression created mountain-sized folds and thrusts, verging E in the north but SE in the south. The resulting surface uplift triggered deposition of huge alluvial outwash fans in the west. Smaller alluvial fans formed along both mountain flanks during the Pleistocene after major surface uplift ended. Pliocene-Pleistocene alluvium was tilted towards the mountain front in the west. Strike-slip/transtension along the East Anatolian Transform Fault and localised sub-horizontal Quaternary basaltic volcanism in the region reflect regional transtension during Late Pliocene-Pleistocene (<4 Ma).</p

Comparisons between Tethyan Anorthosite-bearing Ophiolites and Archean Anorthosite-bearing Layered Intrusions: Implications for Archean Geodynamic Processes

Elucidating the petrogenesis and geodynamic setting(s) of anorthosites in Archean layered intrusions and Tethyan ophiolites has significant implications for crustal evolution and growth throughout Earth history. Archean anorthosite-bearing layered intrusions occur on every continent. Tethyan ophiolites occur in Europe, Africa, and Asia. In this contribution, the field, petrographic, petrological, and geochemical characteristics of 100 Tethyan anorthosite-bearing ophiolites and 155 Archean anorthosite-bearing layered intrusions are compared. Tethyan anorthosite-bearing ophiolites range from Devonian to Paleocene in age, are variably composite, contain anorthosites with highly calcic (An44-100) plagioclase and magmatic amphibole. These ophiolites formed predominantly at convergent plate margins, with some forming in mid-ocean ridge, continental rift, and mantle plume settings. The predominantly convergent plate margin tectonic setting of Tethyan anorthosite-bearing ophiolites is indicated by negative Nb and Ti anomalies and magmatic amphibole. Archean anorthosite-bearing layered intrusions are Eoarchean to Neoarchean in age, have megacrystic anorthosites with highly calcic (An20-100) plagioclase and magmatic amphibole and are interlayered with gabbros and leucogabbros and intrude pillow basalts. These Archean layered intrusions are interpreted to have predominantly formed at convergent plate margins, with the remainder forming in mantle plume, continental rift, oceanic plateau, post-orogenic, anorogenic, mid-ocean ridge, and passive continental margin settings. These layered intrusions predominantly crystallized from hydrous Ca- and Al-rich tholeiitic magmas. The field, petrographic and geochemical similarities between Archean and Tethyan anorthosites indicate that they were produced by similar geodynamic processes mainly in suprasubduction zone settings. We suggest that Archean anorthosite-bearing layered intrusions and spatially associated greenstone belts represent dismembered subduction-related Archean ophiolites

Improved oil recovery using alkaline solutions in limestone medium

In this study, the effect of sodium hydroxide (NaOH) and sodium silicate (NaSiO4) solutions for the improved oil recovery of Garzan (26 API degrees) and Raman (17.2 API degrees) crude oils with variable salinity of the alkaline solutions, and the effect of injection flow rate at the salinity values of the alkaline solutions that yielded maximum oil recovery for both crude oils has been investigated using a one-dimensional unconsolidated limestone reservoir model. As the previous study, the interfacial tension measurements of the given crude oils and alkaline solutions interface have been measured to find the optimum concentrations of the alkaline that give the minimum interfacial tension at the crude oil/alkaline solution interface, at different salinity of the alkaline solutions. Using these optimum alkaline concentrations, 22 displacement runs have been performed; 13 runs with the variable salinity of the alkaline solutions, six runs with the variable injection flow rate, and the remaining three runs were the base floods, performed without oil to see the interaction of alkaline solutions with the porous matrix. The results of the displacement tests showed that the NaOH solutions with increasing salinity, has given the most significant incremental oil recovery, about 3-9% for Garzan crude oil, while the NaOH and NaSiO4 solutions with different salinity did not produced any significant incremental oil recovery for Raman crude oil, when compared with the base waterfloods performed for each crude oil types. Six displacement runs have been performed; three runs for Garzan crude oil and three runs for Raman crude oil at injection flow rates of 400, 300, 200 and 100 cm(3)/h for each crude oil with the salinity of the alkaline solution that yielded maximum oil recovery. The results of the displacement tests showed that injection flow rate of alkaline solution has an important effect on Garzan crude oil and has less effect on Raman crude oil in the scope of oil recovery achieved. The optimum injection flow rates for both Garzan and Raman crude oils have been found, which was 200 cm3/h for Garzan crude oil and 300 cm3/h for Raman crude oil for our model

Modeling of underground gas storage in a depleted gas field

It is possible to predict the behavior of fluids in permeable and porous medium under different operating conditions by using reservoir models. Since geological data and reservoir properties can be defined most accurately by reservoir models, it has been accepted as a reliable prediction tool among reservoir engineers. In this study, a gas reservoir has been modeled with IMEX Module of CMG Reservoir Simulator. Rock properties, gas composition and certain production data were entered to the model as input data and the measured field data were matched with simulated ones. After the 5 year depletion of the reservoir by vertical wells, the average reservoir pressure dropped from an original reservoir pressure of 2150 psi to 1200 psi. This depleted reservoir was planned to be used for gas storage purposes. The remaining gas was used as cushion gas during the conversion of this reservoir to an underground gas storage field. Afterwards, horizontal wells were defined in the model and certain production/injection scenarios were simulated for the gas storage operation

Petrology of ultramafic to mafic cumulate rocks from the Göksun (Kahramanmaraş) ophiolite, southeast Turkey

The Göksun (Kahramanmaraş) ophiolite (GKO), cropping out in a tectonic window bounded by the Malatya metamorphic unit on both the north and south, is located in the EW-trending lower nappe zone of the southeast Anatolian orogenic belt (Turkey). It exhibits a complete oceanic lithospheric section and overlies the Middle Eocene Maden Group/Complex with a tectonic contact at its base. The ophiolitic rocks and the tectonically overlying Malatya metamorphic (continental) unit were intruded by I-type calc-alkaline Late Cretaceous granitoid (~81–84 Ma). The ultramafic to cumulates in the GKO are represented by wehrlite, plagioclase wehrlite, olivine gabbro and gabbro. The crystallization order for the cumulate rocks is as follows: olivine ± chromian spinel›clinopyroxene›plagioclase. The major and trace element geochemistry as well as the mineral chemistry of the ultramafic to mafic cumulate rocks suggest that the primary magma generating the GKO is compositionally similar to that observed in the modern island-arc tholeiitic sequences. The mineral chemistry of the ultramafic to mafic cumulates indicates that they were derived from a mantle source that was previously depleted by earlier partial melting events. The highly magnesian olivine (Fo77–83), clinopyroxene (Mg# of 82–90) and the highly Ca-plagioclase (An81–89) exhibit a close similarity to those, which formed in a supra-subduction zone (SSZ) setting. The field and the geochemical evidence suggest that the GKO formed as part of a much larger sheet of oceanic lithosphere, which accreted to the base of the Tauride active continental margin, including the İspendere, Kömürhan and the Guleman ophiolites. The latter were contemporaneous and genetically/tectonically related within the same SSZ setting during the closure of the Neotethyan oceanic basin (Berit Ocean) between the Taurides to the north and the Bitlis-Pütürge massif to the south during the Late Cretaceous. © 2019 China University of Geosciences (Beijing) and Peking UniversityGovernment Council on Grants, Russian Federation Firat University Scientific Research Projects Management Unit: MMF2002BAP41 YDABÇAG-199Y011Emilio Saccani, Laura Gaggero and anonymous reviewer are thanked for their constructive and very valuable comments that improved the quality of the paper. The authors would like to thank Fabio Capponi for performing XRF major and trace element analyses at Geneva (Switzerland) University. Dan Topa is thanked for his guidance during the microprobe analysis at Salzburg (Austria) University. This research was supported by TÜBİTAK ( YDABÇAG-199Y011 ) and the Çukurova University Scientific Research Projects ( MMF2002BAP41 ). OP acknowledges the Open Fund (GPMR201702) of State Key Lab of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan. CI acknowledges subsidy by the Russian Government to support the Program of competitive growth of Kazan Federal University. Appendix