The Evidence of multiple origin for calcareous springs in the Abe Ask region (Southeast of Damavand volcano) using isotopic data، water geochemistry and Remote Sensing studies.

There are several calcareous springs and travertine deposits on Southeast flanks of Damavand volcano in Abe Ask area (85 km northeast of Tehran¡ Central Alborz zone). In this study¡ based on carbon and oxygen isotopic signatures on travertine deposits¡ the source of spring water was evaluated. Isotopic signatures show that δ13C and δ18O values enrichment in travertines gradually away from the springs. According to the primitive value of δ13C(CO2)¡ travertine was deposited from a hydrothermal metasomatic fluids. Concerning to the linear trend between the δ13C– δ18O of travertine¡ the main hydrothermal metasomatic fluid (that was responsible for travertine deposition) was probably mixed with fluids of different origins. According to the isotopic analysis¡ the mantle-sea origin is suggested for the dissolved CO2 of water springs¡ in addition¡ the results of water geochemical data also confirmed a deep source for the Abe Ask water springs. According to the remote sensing investigation on satellite images¡ the distribution of travertine and faults lineation and drainage pattern¡ suggest the strong effect of surface and tectonic processes¡ in controlling the placing and distribution of the travertine. Finally¡ geochemical data on water springs and isotope investigations on travertine reveal both surface and deep-water source contribution in formation of the Abe Ask water springs.