Geophysical Modelling Using Gravity Data of Meteorite Impact Crater at Bukit Bunuh, Lenggong, Perak, Malaysia

A geophysical survey using gravity method was conducted at Bukit Bunuh, Lenggong, Perak, Malaysia, to determine the occurrence of a subsurface impact crater, based on the discovery of meteorite impact rock, suevite, in the study area. A standard correction was applied to all the gravity data to produce Bouguer gravity anomaly of the study area. The Bouguer gravity anomaly was used to produce several maps of gravity anomalies by filtering processes and relate them to the geological structure and tectonic history of the study area. Data processing and interpretation were conducted using geophysical software, Oasis Montaj. This software was used in a number of gravity data filtering processes, such as Low Pass Filter (LPF) and the Total Horizontal Derivative (THD). Bouguer gravity anomaly map shows a circular structure in Bukit Bunuh area which is interpreted as a remnant of meteorite impact crater. The gravity anomaly appears to decrease from the edge of the crater and increases at the center. This feature indicates a complex crater structure which has central uplift. The Total Horizontal Derivative map of residual gravity anomaly shows structural trend such as lineaments and faults that dominant to the northwest‐southeast direction. A model was produced using GM‐SYS 3D software to determine the geometry of the impact crater. The interpreted 3‐D model shows a diameter of the impact crater was approximately 2368 m and depth of about 400 m. The model of the crater appears to tilt toward southeast, which illustrates the ancient meteorite that hit this area about 1.83 million years ago possibility came from northwest direction