Yazarlar

  • MakaleYalnız künye2015
    Determination of the Crustal and Thermal Structure of the Erzurum-Horasan-Pasinler Basins (Eastern Türkiye) Using Gravity and Magnetic Data

    Maden, Nafiz; Aydin, Ali; Kadirov, Fakhraddin

    The Erzurum-Horasan-Pasinler basin, which surrounds Miocene rocks, is oriented approximately E–W and is located in Eastern Anatolia (Türkiye). East Anatolia, where ophiolitic and young volcanic rocks are widespread, is situated in the Alpine–Himalayan fold-thrust fault belt. The NW–SE trending North Anatolian Transform Fault Zone and the NE–SW trending East Anatolian Transform Fault Zone, formed by the compressional regime of East Anatolia, control the main tectonics of the study region. While the Moho and Conrad depths of the study region are 43.0 and 20.9 km, respectively, the average sedimentary thickness has been determined to be 5.2 km by using the power spectrum method. On the other hand, it is found that the depth of the Moho in the region varies from 41.0 to 44.5 km and the depth of the Conrad discontinuity varies between 22 and 26 km, as computed using empirical equations. The basement of the sedimentary layer is calculated to be 6 km by using inversion results applied to the residual gravity data. The Curie point depth and average heat flow value in this region are calculated as 18.0 km and 89.1 m Wm−2, respectively. Geotherm calculations reveal that the Moho temperature is 1,028.0 °C based on the crustal model. The high heat flow values obtained are attributed to tectonic activities and melting of the lithospheric mantle caused by upwelling of the asthenosphere.

  • MakaleYalnız künye2006
    Three-directional extensional deformation and formation of the Liassic rift basins in the Eastern Pontides (NE Turkey)

    Eyüboǧlu, Yener; Bektaş, Osman; Şeren, Aysel; Maden, Nafiz; Özer, Rahşan; Jacoby, Wolfgang R.

    The Eastern Pontide magmatic arc (NE Turkey) was rifted by the polyphase extensional tectonic regimes in the Early Jurassic. While alternated volcanics and siliciclastic sedimentary rocks accumulated during the episodic tectonic subsidences, thermal subsidence is manifested by sedimentation of the red pelagic limestones of the Ammonitico Rosso during the Pliensbachian. The trends of the Liassic basins extending in NW-SE, E-W, NE-SW directions coincide with the gravity and magnetic lineament anomalies and corresponding fault zones that are responsible for the paleotectonic and neotectonic evolutions of the Eastern Pontide magmatic arc. These mutual relationships suggest that the faults making up the architecture of the Liassic basins might have operated during the Paleozoic, Mesozoic and Cenozoic times in different manners. Neptunian dikes, filled by the early rift siliciclastic and following fossiliferous red pelagic limestone implying the repeated extensional tectonic regimes, are also parallel to the main extensions of the Liassic basins. The poles of the contemporaneous neptunian dikes suggesting two or three extensional conjugate fracture systems are in accordance with the dip directions of the rift sediments accumulated in the same conjugate normal fault systems. Assuming that the Liassic basins with Ammonitico Rosso are coeval, multi-armed rift basins might have opened by the mode of the three-directional extension rather than reactivation of faults in the different times.