Iso-Naakkima, a circular structure filled with Neoproterozoic sediments, Pieksämäki, southeastern Finland

Abstract

A circular Bouguer gravity anomaly with a minimum of -4.0 mGal and halfamplitude width of 2 km was recognized at Lake Iso-Naakkima (6211'N, 2709'E), southeastern Finland. The gravity low is associated with subdued aeromagnetic signature and notable airborne and ground electromagnetic anomalies that indicate low bedrock resistivity.