Structural Architecture of the South Caspian Basin: Insights From Seismic Interpretation and Regional Geological Analysis

ABSTRACT

The South Caspian Basin (SCB) is one of the world's major hydrocarbon provinces, characterized by an exceptionally thick sedimentary succession, complex deep‐basin architecture and high hydrocarbon potential. Although numerous studies have addressed individual sectors and tectonic elements of the basin, detailed structural information remains fragmented across the Azerbaijani, Turkmen and Iranian sectors. The aim of this study is to integrate the available geological and geophysical information within a single basin‐wide framework and to reconstruct, at a consistent regional scale, the principal structural levels and sediment‐thickness patterns of the entire SCB. Data integration and interpretation were carried out using the GeoFrame software package. Structural maps were constructed for the crystalline basement surface and the tops of the Cretaceous, Miocene and Lower Pliocene Productive Series, and isopach maps were compiled for the Paleogene–Miocene succession and the Productive Series. The maps integrate seismic interpretation, drilling and well‐log information and published geological and geophysical constraints from the Azerbaijani, Turkmen and Iranian sectors within one consistently scaled regional mapping framework. The resulting basin‐wide reconstruction refines the spatial relationships amongst the Azerbaijan, Ogurchin and Iranian depressions, major structural highs and regional deep‐seated fault systems, and documents a progressive increase in structural complexity from the basement and Cretaceous levels to the Miocene and Productive Series. To the best of the author's knowledge, a comparable integrated set of structure and isopach maps covering the principal stratigraphic levels across all three national sectors of the SCB has not previously been published. The reconstruction also permits evaluation of alternative deep‐structural interpretations, including the possible influence of interpreted rift‐related zones; these deeper interpretations remain hypotheses requiring verification by future deep seismic imaging and drilling. The integrated maps provide a regional framework for evaluating deeply buried exploration targets and for future geological and geophysical investigations across the entire basin.