From Isolated Caves to Spatial Systems: A Geoarchaeological Re-reading of Underground Spaces in the Zagros Mountains

Prevailing interpretations of large underground cavities in carbonate terrains are predominantly based on karst-related genetic models, in which dissolution-driven hydrological processes are assumed to be the primary mechanism of formation. While effective for explaining certain cave types, these models commonly rely on an implicit assumption: that underground cavities should be analyzed as isolated natural features. This assumption has limited the recognition of broader spatial patterns and system-level organization.

This study proposes a geoarchaeological, system-based approach to the interpretation of underground spaces, using the Zagros Mountains as a key case study. Given the extensive carbonate lithology of the region, classical karst theory would predict cave development closely associated with active or fossil drainage networks. However, field observations reveal a contrasting pattern, with numerous underground openings located at elevated positions, often on cliff faces or near ridgelines, lacking any evidence of hydrological concentration or outlet channels.

A focal example is provided by the Deh Sheikh area (central Zagros), where multiple underground entrances occur at the same elevation level and are separated by relatively regular horizontal distances. Such repeated and level-aligned configurations are difficult to reconcile with stochastic karstic dissolution processes and instead suggest a coherent spatial logic that becomes visible only when these features are considered collectively rather than individually.

Additional evidence includes stable arched geometries and persistent cavities that contrast with the irregular, downward-oriented erosion expected from water-dominated processes. These observations indicate that natural processes observed today are largely secondary modifications, overprinting earlier phases of space formation.

Rather than rejecting natural cave formation mechanisms, this study argues that, in the Zagros region, a system-based geoarchaeological framework provides a more coherent and parsimonious interpretive model. The results highlight the importance of analytical scale and interdisciplinary perspectives in re-evaluating underground spaces.