Large meteorite impacts pose small but potentially significant risks for the future of civilization. The largest impacts precipitate mass extinctions. Knowing the possible consequences of such events, it is important to study ancient terrestrial impacts because they provide records of environmental devastation and give insight into predicting the effects of future collisions with meteorites. Over the last two decades, an enormous amount of information has been gathered concerning large impacts, but the effects of mid-sized impacts have not been documented thoroughly.
The Weaubleau structure of west-central Missouri is a possible impact site. It contains many of the hallmarks of impacts: locally deformed rocks (intensely fractured, faulted, and folded strata), an uplifted central (rebound?) area, and microscopic features that seem to have developed from shock pressures. Ten shallow drill cores already have been recovered from the structure, providing a rare glimpse at the depth of deformation within the structure. If evidence ultimately supports the idea that Weaubleau is an impact, it would be the third mid-sized impact in southern Missouri; Decaturville and Crooked Creek are both widely accepted as impact structures. Other scientists have hypothesized that these features, together with structures in Kansas and Illinois, record a serial impact. All of these features fall on the same trend, but Crooked Creek and Decaturville are deeply eroded, and their ages are poorly understood. In contrast, the Weaubleau structure was buried shortly after the event that produced it, and it is now partly exposed by modern erosion. Study of the Weaubleau structure offers an extraordinary opportunity to investigate a possible impact, determine its age, examine the lateral extent of devastation, and examine potential relationships with other structures in Missouri.
