Petrological characteristics of the maden complex (Eastern Taurus-Turkey)

The study area covers the region between Maden (Elazığ) and Kale-Pütürge (Malatya) district where the Maden Complex is seen most in common. In the east, the Maden Complex unconformably overlies the Guleman Ophiolite, while in the west the Maden Complex is seen in two different positions with reference to the Pütürge Metamorphic Massif. The Maden Complex in the Ergani (Diyarbakır)-Maden (Elazığ) is divided into the lower volcano-sedimentary unit and upper volcanic unit. Each of these units displays vertical transitional contacts. The lower volcano-sedimentary unit consists of mafic volcanic including limestone blocks, mudstones and pelagic limestones are above basal conglomerate. Upper volcanic unit; on the other hand, consists of basalt, basaltic andesite, andesite, dacite, diabase and pyroclastic rocks. In the Pütürge-Kale area, the Maden Complex unconformably overlies the Koçali Ophiolites while is tectonically overlain by the Pütürge Metamorphic Massif. In the north of the Pütürge Metamorphic Massif, this complex unconformably overlies the Pütürge Metamorphic Massif. The Maden Complex in this area is subdivided into four formations, from bottom to top; these are Ceffan, Arbo, Melefan and Karadere formations. The Ceffan formation forms the basis of the Maden Complex, unconformably overlies the Pütürge Metamorphics while is conformably overlain by the Arbo Formation consisting of limestone, shale, sandstone and conglomerates. The Arbo Formation conformably overlies the Ceffan Formation, while it is conformably overlain by the Melefan Formation. The Arbo Formation consists of Lutetian limestone including Nummulites sp. and foraminifera fossils. The Melafan formation conformably overlies the Arbo Formation while is conformably overlain by the Karadere Formation. The unit consists of mudstones, marl, spilitic basalt and pelagic limestones. The Karadere formation conformably overlies the Melafan formation while it is tectonically overlain by the Ispendere Ophiolites and the Elazığ Magmatics. The unit consists of basalt, diabase and pyroclastic rocks. The result of geochemical studies, according to N-MORB normalized diagrams present for different rock types share similar patterns characterized by enrichment of large ion lithophile elements (LILE), depletion of high field strength elements (HFSE) and a positive Pb spike. The rocks display enrichments in LREE, and are characterized by relatively flat HREE patterns. Sr-Nd isotopic ratios of the volcanic rocks vary between 0.70352-0.70748, and 0.51207-0.51292, relatively. Besides ε(Nd)(T) values of the rocks vary between -10.0 and 6.7. Based on trace element, REE and Sr-Nd isotopic compositions of the examined volcanic and sub-volcanic rocks, the Middle Eocene aged Maden Complex magma derived from E-MORB and N-MORB-like source enriched by of previous subduction components. Both fractional crystallization and crustal contamination played an active role as the mechanism in the evolution of the studied rocks. In the study area, Late Cretaceous post-collision caused the ophiolites overthrust the Arabian Platform along with the Bitlis-Pütürge Metamorphic Massifs thrust on the ophiolites and resulting significantly thickening of the crust. A gap, was caused by dragging into asthenosphere of the base of the Bitlis-Pütürge Metamorphic and Upper Cretaceous subduction zone with lower ophiolites, was filled by asthenosphere. The magma was formed by adiabatic upwelling causing partial melting of the collapsed parts release of the volatile, created Maden Complex above of the either Pütürge Metamorphic or ophiolites in some part of the area by upwelling. Key Words: Maden Complex, Eastern Taurus, Magmatism, E-MORB and N-MORB, Fractional Crystallization, Crustal Contamination.