30,000 Years of the southwestern Lake Urmia (Iran) paleoenvironmental evolution inferred from mineralogical indicators from lake and watershed sediments

In order to understand the pattern and trends of environmental evolution Lake Urmia (Iran), one largest terminal lakes in Western Asia before its level drop over past two decades, sediment cores (Golman 6, 8.0 m; Golman 7, 12.5 m) were collected from recently dried-out southwestern part lake. These represent a continuous sedimentary sequence, composite core, that was extensively studied for grain size, total mineralogy including clay minerals, carbonates their crystallinities, comparison with basin geological formations within reliable AMS-14C timescale. deposits cover time-span 30 ca 2 cal kyr BP. Grain-size siliclastic fractions lower core consists fine-silt particles likely representing lacustrine while top sediments are characterized by variable composition sand silt. At about BP, our proxies indicate low lake stand even drying out at coring site, which followed water rise establishment conditions between 29.9 20.2 Since then, all data suggest lake’s highly unstable conditions. Subsequently, clearly levels sometimes recorded during 20.2–15.3 13.3–11.8 BP 5.6–4.1 intervals. contrast, re-established 15.3 13.3 11.8 5.6 4 0.1 2.3 High can be attributed Bölling/Alleröd warming, following regressive phase period corresponds Younger Dryas period. Early-Mid Holocene, environment high aragonite salt contents, highlighting evaporative as like 29.9–20.2 Our results allowed Late Quaternary climate reconstruction scale record change larger scale.