Investigation of helium isotope variations of alkaline volcanic rocks In Osmaniye Region Turkey

The noble gases, in particular helium isotopes, provide valuable information on the mantle source of recentbasaltic volcanism, especially when linked to trace elements and radiogenic isotopes. Although the alkalinevolcanics in the Kütahya region have been studied in detail by several works by means of trace element variations,radiogenic dating and isotope systematics, noble gas isotope compositions that could significantly contribute todynamics of volcanism have not been investigated yet. In this study which aims to fill the deficiency of such data,helium isotope compositions of olivine-basalts in Kütahya region are measured.In this study we report helium isotope compositions of olivine from basalts. In olivine-basalts in alkalinevolcanic rocks from the Kütahya region, western Turkey, are investigated. 3He/4He range from 3.0 to 5.19 Ra.These low helium isotope values are most probably indicative of a lithospheric mantle source. Kütahya alkalinevolcanics are enriched in incompatible elements and show prominent negative Ti, Nd and Ta anomaly. Primitivemantle normalized trace element concentration patterns clearly display continental crustal contamination.Chemical compositions and helium isotope systematics imply contribution of a lithospheric mantle source andcontamination of continental crust in the genesis of the Kütahya alkaline lava

Investigation of Helium Isotope Vari ations of Alkaline Volcanic Rocks in Kutahya Region

The noble gases, in particular helium isotopes, provide valuable information on the mantle source of recentbasaltic volcanism, especially when linked to trace elements and radiogenic isotopes. Although the alkalinevolcanics in the Kütahya region have been studied in detail by several works by means of trace element variations,radiogenic dating and isotope systematics, noble gas isotope compositions that could significantly contribute todynamics of volcanism have not been investigated yet. In this study which aims to fill the deficiency of such data,helium isotope compositions of olivine-basalts in Kütahya region are measured.In this study we report helium isotope compositions of olivine from basalts. In olivine-basalts in alkalinevolcanic rocks from the Kütahya region, western Turkey, are investigated. 3He/4He range from 3.0 to 5.19 Ra.These low helium isotope values are most probably indicative of a lithospheric mantle source. Kütahya alkalinevolcanics are enriched in incompatible elements and show prominent negative Ti, Nd and Ta anomaly. Primitivemantle normalized trace element concentration patterns clearly display continental crustal contamination.Chemical compositions and helium isotope systematics imply contribution of a lithospheric mantle source andcontamination of continental crust in the genesis of the Kütahya alkaline lavas

Major and Trace Element Concentrations of Kula Volcanics andInvestigation of Source Composition

Kula alkaline volcanics, western Anatolia, occur in an E-W trending graben system that was resulted from the Aegean extensional regime. Kula alkali lavas are distinguished in three different sequences, namely Burgaz, Elekçitepe and Divlittepe. The Kula basalts with SiO2 <50% belong to silica undersaturated alkaline suite. Burgaz and Elekçitepe samples are basanite and tephrite in composition while the Divlittepe volcanics are phonotephrite. In MORB and PM (primitive mantle) normalized diagrams, Kula lavas with high LILE and light REE patterns show enrichment in incompatible elements. However incompatible trace element patterns exhibit almost similar trends in many respects to OIB except in Sr, Rb, Ba, Th, Nb, U and K. The enrichment level of these elements for Kula lavas is considerably higher than for OIB. This indicates that enriched mantle source (EM, HIMU) or partly contamination by continental crust contributed to generation of Kula volcanics. However primitive mantle normalized trace element concentration patterns clearly rule out continental crustal contamination due to lack of Nb, Ta and Ti anomalies. It is concluded that geochemical composition of Kula lavas indicates derivation from OIB-like asthenospheric mantle and contribution of enriched mantle sourc