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Department of Mining & Metallurgical Engineering, Yazd University
10.22034/anm.2026.23980.1712
Abstract
The Zagros Basin ranks among the world’s most prolific hydrocarbon provinces, featuring multiple active petroleum systems and a dense concentration of oil and gas fields. The Cretaceous Garau Formation represents a regionally extensive, organic-rich source rock that spans across southwestern Iran, Iraq and Kuwait. This study presents a regional investigation of the biomarker and isotopic characteristics of the Garau source rock across southwestern Iran, northeastern and southeastern Iraq. High-quality results from GC, GC–MS, and carbon isotope analyses of bitumen extracted from the Garau Formation were compiled for this purpose The dataset includes biomarker indices and isotopic measurements from 33 fields and outcrops located within the Lorestan Basin, Dezful Embayment, Abadan Plain, and northern and southern Iraq. The Pristane/Phytane ratio lower than one indicates deposition under reducing marine conditions. Pr/n-C17 and Ph/n-C18 ratios, together with relative abundances of C27, C28, and C29 steranes, confirm the presence of Type II kerogen and a predominantly marine depositional environment highlighting a strong hydrocarbon generation potential. Tricyclic triterpane ratios (C22/C21, C24/C23), hopane ratios (C31R/C30H, C29/C30), and aromatic ratios (DBT/P, Gam/C30) further support carbonate-rich lithology and normal-salinity marine deposition for the Garau Formation. Moreover, Stable carbon isotope composition and CV values indicate a dominant marine organic matter input. Thermal maturity assessment reveals that the Garau Formation in the eastern Lorestan sub-basin remains immature, whereas in other studied areas it has entered the peak to late oil window, generating substantial hydrocarbons over geological timescales. These findings underscore the major role of the Garau Formation in regional petroleum systems and offer valuable insights for exploration-risk assessment and development strategies in the Zagros Basin and contiguous areas.
Hosseiny, E. and Hajakbari, M. A. (2026). Study and comparison of biomarker and isotopic characteristics of Garau source rock in southwestern Iran and adjacent areas. Journal of Analytical and Numerical Methods in Mining Engineering, (), -. doi: 10.22034/anm.2026.23980.1712
MLA
Hosseiny, E. , and Hajakbari, M. A. . "Study and comparison of biomarker and isotopic characteristics of Garau source rock in southwestern Iran and adjacent areas", Journal of Analytical and Numerical Methods in Mining Engineering, , , 2026, -. doi: 10.22034/anm.2026.23980.1712
HARVARD
Hosseiny, E., Hajakbari, M. A. (2026). 'Study and comparison of biomarker and isotopic characteristics of Garau source rock in southwestern Iran and adjacent areas', Journal of Analytical and Numerical Methods in Mining Engineering, (), pp. -. doi: 10.22034/anm.2026.23980.1712
CHICAGO
E. Hosseiny and M. A. Hajakbari, "Study and comparison of biomarker and isotopic characteristics of Garau source rock in southwestern Iran and adjacent areas," Journal of Analytical and Numerical Methods in Mining Engineering, (2026): -, doi: 10.22034/anm.2026.23980.1712
VANCOUVER
Hosseiny, E., Hajakbari, M. A. Study and comparison of biomarker and isotopic characteristics of Garau source rock in southwestern Iran and adjacent areas. Journal of Analytical and Numerical Methods in Mining Engineering, 2026; (): -. doi: 10.22034/anm.2026.23980.1712
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