3‐D seismic mapping of a kilometer‐scale Neogene probable impact crater in Saudi Arabia

A previously unreported crater is identified on 3-D reflection seismic data onshore eastern Saudi Arabia. It is 6.5 km in diameter and buried a few hundred meters below ground level, yet the only surface expression is a subtle topographic depression in the present-day environment of sabkhas and windblown dunes. Strata are affected by the crater to a depth of approximately 1 km and are tied to a drilled well, 17 km from the crater rim, that provides lithology and age of the deformed sediments, which range from Neogene to Upper Cretaceous. The crater age is late Miocene or Pliocene in this interpretation. The structural geology of the crater is clearly imaged in 3-D across a present-day depth range of 200–600 m below ground level. Structural elements include a central high surrounded by well-developed concentric and radial fault sets that bound fault blocks in the crater walls. Causal mechanisms are examined with a focus on dissolution tectonics since the affected strata include evaporites. However, the scale, unique structural style, and vertical extent of the crater that reaches far below the evaporites rule out evaporite dissolution as the primary genetic mechanism. Diapirism of deep salt and volcanism are also rejected, leaving hypervelocity asteroid or comet impact as a preferred but unproven interpretation. The size, shallow depth of burial, and complete preservation of this structure make it an excellent candidate for tailored future data acquisition and research into crater geometry and mechanics.