ORGANIC GEOCHEMISTRY OF AL-AZRAQ BASIN, JORDAN, INTERPRETATION OF PALEOENVIRONMENTS USING BULK ORGANIC MATTER

The Al-Azraq basin is the second largest basin on Jordan Plateau containing a long and detailed record of paleoenvironments. Analysis of six hundred and twenty one samples from 23m of playa lake sediment reveals the presence and distribution of organic matter. Stable isotope geochemical methods link sediment geochemistry to biological processes revealing critical new information about organic matter sources, sediment accumulation, and formation environments. Organic matter ranges from 0.5% to 2.8% of the total sediment. The δ¹³C values range from -26.09 to -15.65 becoming more negative with higher concentrations of organic matter. The C/N ratios identified organic matter of marine-like algae indicating periods of hypersalinity in the basin, and phases of mixed terrestrial organic matter. Analyses reveal a diversity of environments in the Al-Azraq basin throughout the past that differs significantly in moisture from the present and are the basis for dividing the Al-Azraq basin into five environmental zones.