Complex sentence: The identification as an impact crater is based mainly on morphology, faulting pattern, and on exclusion of other possible mechanisms; as of 2009 there were still no reports of definite evidence, such as shatter cones or shocked quartz.
Split into simpler sentences: The identification as an impact crater is based mainly on geomorphology, faulting pattern, and on exclusion of other possible formation mechanisms. As of 2009 there were still no reports of definite evidence, such as shatter cones or shocked quartz.