Integrated borehole and outcrop study for documentation of sea level cycles within the Early Eocene Naredi Formation, western Kutch, India

Abstract

A combined micropalaeontological and sedimentological investigation of the Early Eocene Naredi Formation (thickness varying between 20m and 60m) reveals a complete third-order cycle and six fourth-order sea level cycles. Within the third-order cycle the foraminiferal abundance and diversity gradually increase upwards and reach their maximum values at about 41m thickness above the base of the formation and subsequently decrease upward and finally give way upward to an unfossiliferous zone at the topmost part. Within a fourth-order cycle foraminiferal abundance and diversity exhibit a similar increasing and decreasing pattern. Bounded between two unconformities the Naredi Formation represents a sequence. A highly fossiliferous Assilina-bearing limestone interval represents the maximum flooding zone which separates the transgressive systems tract at the base from the highstand systems tract at the top.