A geophysical investigation of the Roter Kamm impact crater, Namibia

Abstract The Roter Kamm impact crater is located in the southern Namib Desert. The crater has a diameter of 2.5 km and belongs to the category of simple, bowl‐shaped impact craters, with an elevated rim of fractured target rock. The crater's interior is completely buried beneath sediments, preventing extensive surface investigations of the bedrock topography. Geophysical investigations were carried out to better characterize the sediment cover, the resulting shape of the crater, and the infill of the impact structure. Two electromagnetic techniques, transient electromagnetics and audiomagnetotellurics, were used to study the subsurface resistivity structure across and beyond the Roter Kamm crater along two transects. The postimpact sediments inside the crater reach thicknesses up to 340 m. The surface of the underlying brecciated zone exhibits the characteristic bowl‐shape of a simple crater. A prominent conductive anomaly was found inside the sedimentary succession, indicating the presence of water. The boundary between fluid‐saturated and dry material likely marks the transition from postimpact sediments to impact breccia. Our results provide the first geophysical model of the sedimentary infill of the Roter Kamm impact crater derived from electromagnetic methods.