Geochemistry and origin of elements in the Azarshahr travertine deposits (Eastern Azarbaijan)

Travertine deposits cover a vast area in the southwest of Azarshahr (East Azarbaijan province) and in some parts there are active springs which currently deposit these types of sediments. Regarding the field observations in the Azarshahr area, the typical morphology of Azarshahr travertine deposits is in situ and consists of the mounds, fissure-ridge and cascades. Geochemical studies on the travertine deposits of the Taptapan and Qizildagh springs revealed that the amount of iron in travertine deposits clearly emphasizes their thermogenic nature. The amounts of strontium, barium and beryllium also indicate the thermogenesis and calcareous, evaporative or dolomite origin. The depleted oxygen isotope (δ18O) and enriched carbon isotope (δ13C) is also indicator of thermogenic source, and carbonate source rocks for these deposits. Based on geochemical studies, it can be concluded that hydrothermal fluids may have initially taken the CO2-derived from magma, and during the upward movement with carbonate rocks, decarbonization has been occurred. These fluids transport CO2 from carbonates, and then they appear as spring’s water at the surface and precipitate travertine due to the rapid release of CO2.