HOW WILL WE RECOGNIZE BURIED IMPACT CRATERS IN TERRESTRIAL SEDIMENTARY BASINS?

Abstract

Criteria that are deemed critical for recognition of terrestrial impact craters include features from hand specimens such as shock metamorphic structures. Although these criteria have been selected because they are unique physical products of bolide impact, strict adherence to these criteria means that we cannot positively identify buried astroblemes that are tomographically imaged on three-dimensional seismic data, but are undrilled. Because many of Earth's deeply buried structures may never be drilled because of prohibitive cost and lack of commercial incentive, a large proportion of as yet-undiscovered terrestrial astroblemes, including the best-preserved examples, may remain unclassified and be excluded from impact-structure research. A framework for the identification of impact structures imaged on three-dimensional seismic data is proposed, on the basis of geometrical criteria plus additional image-quality and preservation criteria that assign a level of confidence to the assessment.