New insights for the mantle source components of the most primitive recent basaltic rocks from central and western Anatolia: Evidences for the involvement of pyroxenite and the peridotite source domains

Basaltic activities  developed  extensively in central and western Anatolia since middle –Miocene to quaternary time, the most primitive lavas are  situated at  the eastern end of  central Anatolia, (southern Sivas) and the most recent ones  are situtated in central (basaltic cinder cones at south of Hasandağ) and also in western Anatolia (Kula region),  Among those  primitive recent  lavas, mantle sources that are responsible for the generation of basaltic rocks is  still a matter of a debate.          

Previous studies suggested  that  spinel peridotite source   is the dominant source  component  for many of the basaltic rocks which are situated in several different locations in central Anatolia, including, Erciyes and Hasandağ stratovolcanoes,  Erkilet, Develidağ, Karapınar vents and Salanda fissure eruptions while Sivas fissure basalts in the east,  Gediz and Kula  basalts in the west, were  derived  mostly  from  the  garnet peridotite sources, but , the  specific  incompatible element ratios  and the melting model based on Rare Earth Elements obviously  indicate that  these basaltic rocks could not be solely generated  from  the garnet- spinel transition zone,   instead another mantle source component need to be involved  in the generation of the basaltic rocks.

Tb/Yb(N) and Zn/Fe  ratios provide significant values   in order to constraint for the magmas  generated from the asthenosphere.  Tb/Yb(N) ratio seperates  garnet – spinel transition [1]  and Zn/Fe  ratio  displays separation between the peridotite-derived (Zn/Fe <12, [2,3]) and pyroxenite-derived (13-20 [2,3]) melts.  Zn/Fe, as well as  the  Tb/Yb(N) ratios and the melting model display  that single spinel  source   component  is not solely   responsible for  the generation of  the basaltic rocks,   pyroxenite  source domain  should    also  be involved in   during  the genesis of these rocks as well, besides, the  contributions from  the both of the  mantle source domains also explain the  depleted  magma nature that is observed  in some of recent basaltic rocks ( e.g, Salanda  and  Hasandağ  volcanic  systems) which is diffrent  from the dominated alkaline character,  generally observed  as  the   final products  of central Anatolian  magmatism   

1.Wang et al., 2002, J.Geophys.Res.vol:107,ECV 5 1-21

2 .Le Roux, et al.,2011,EPSL, vol:307, 395-408

3. Ducea, et al.,2013, GEOLOGY, Vol:41, 413-417

This study   is financially supported by Hacettepe University, BAB project no: FHD-2018-17283