简介:Geologicmarksrelatedtoextraterrestrialimpactevents,suchasimpactsplitgravels,impactbrecciatelayers,impactdikes,microirghizites,microtektites,especiallymeteoriticresidues,werediscoveredontheboundarybetweenSinian/CambrianatTianmenshanofWesternHunan,whichmaypossiblydemonstratethatanextraterrestrialimpacteventhaseveroccurredthereontheS/Cboundary.