Regional gas geochemistry in an active tectonic zone, Erzurum Basin, eastern Turkey

Abstract

The Karasu Plain is an intermontane sedimentary basin with a Miocene—Quaternary volcanicbasement, andesitic-basalticlava flows and fissure eruptions of basaltic lava. It was filled in the early Quaternary by lacustrine fan-delta deposits, and later by fluvial-alluvial fan deposits. The basin is characterized by NNE-SSW trending sinistral wrench faults on its eastern margin and ENE-WSW trending reverse faults on its southern margin. Both systems of active faults intersect very near to Erzurum, which is considered to be the most likely site for the epicentre of a probable future large earthquake. Regional gas geochemistry has therefore been undertaken adjacent to the city of Erzurum, in order to characterize radon levels over the varied lithologies, examine the potential for geological fault mapping and assess the status of fault activity. Initially,41 sites were sampled and analysed for Rn, CO 2 , O 2 and CH 4 in soils along three traverses to the east (8.26km and 4.5km length) and to the west (6.8km length) of Erzurum. During the first investigation, 495 Rn determinations were made from 165 samples at 41 sites over a ten-day period, during which a small earthquake (M=2.95) occurred. Another 211 sites have been subsequently used for Rn investigations including one traverse through the centre of the city. Additionally,water samples were degassed for Rn and soils tested at five key sites around the Erzurum Plain. Radon was readily detected in soils at all sites. Both 222 Rn and 220 Rn were present at most. Soils over major lithologies gave characteristic signals and, in all traverses, anomalously high values coincided with active faults. Little correlation was found between spring gases (thermal and cold) and adjacent soils. De-gassed spring water Rn values proved highest along the southern margin of the basin and CO 2 values were highest along the northern edge.

The Local Earthquake Tomography of Erzurum (Turkey) Geothermal Area

“…It is emphasized that the geothermal potential of the region in the geochemical studies carried out in Erzurum and its surroundings (Bayraktutan et al 1996;Yuce and Taskiran 2013;Kilic and Inceoz 2015;Kaygusuz et al 2018). Bayraktutan et al (1996) reported signs belonging to the hot spring water in the studies carried out on active faults in Erzurum and its surroundings. Yuce and Taskiran (2013) found that the thermal waters had deep mantle traces and these waters were magmaic based, as a result of the analysis of gas and water samples taken from thermal waters with the temperature of 57 degrees.…”

“…The geological structure and tectonic evolution of Erzurum region and its surroundings have been mainly investigated by Keskin et al (1998), Yarbasi and Kalkan (2009), Kocyigit and Canoglu (2017). Moreover, there are some attempts associated with geothermal potential (Bektas et al 2007;Gulec and Hilton 2016), geochemical (Bayraktutan et al 1996;Keskin e al. 1998;Italiono et al 2013;Yuce and Taskiran 2013;Kilic and Inceoz 2015;Gulbay 2015;Kaygusuz et al 2018) and petroleum (Oruc et al 2013) features of the area.…”

Experimental performance evaluation of a closed-loop vertical ground source heat pump in the heating mode using energy analysis method

“…It was filled in the early Quaternary by lacustrine fan-delta deposits, and lather by fluvial-alluvial fan deposits. These deposits were derived from calkaline volcanics consisting of basaltic, andesitic, dasitic and rhyolitic lava flows with subordinate pyroclastic products (Kocyigit et al, 1985;Bayraktutan et al, 1996). Alluvial sequence, almost 300-500 m thick and rests unconformable on the basement formations, is represented by sedimentary layers composed of weakly cemented, EXPERIMENTAL PERFORMANCE EVALUATION OF GSHP SYSTEM 1507 variable sized, rounded, subrounded mixture of gravel, coarse sand, sand and silt.…”

Ostracod Fauna and Environmental Characteristics of Köprüköy / Erzurum (East Anatolia) Region

“…Stratigraphy-sedimentology studies were completed by Demirtaşlı et al (1965), and Gürbüz and Gülbaş (1999). Tokel (1984), Erdoğan (1967Erdoğan ( ), Özcan (1967, Şengör and Kidd (1979), Şengör (1980), Yılmaz and Şener (1984), Şaroğlu (1986), Şaroğlu and Yılmaz (1984), Koçyiğit (1985), Barka et al (1987), Bayraktutan et al (1996), Bayraktutan (1999), Bozkuş (1999), Beer et al (2003), Keskin (2005), and Gelişli and Maden (2006) studied tectonics and magmatism. Paleontology was studied by Şafak (2013) and Vasilyan et al (2014).…”