This study presents the geomorphology of the alluvial plain that between the villages of Motozintla
and Mazapa de Juárez exposes 31 alluvial fans, 5 hanging terraces and 13 ramps. Fourteen of these alluvial
fans have been truncated by the Polochic fault, exposing maximum uplifts of ~12 m. The internal structure of
truncated fans consists of single massive beds (monolithologic fans) or stacked beds (polygenetic fans).