Recent research leads scientists to believe that Hecates Tholus erupted explosively about 350 million years ago, which is a not that long ago for Mars. The eruptions created depressions on the flanks of the volcano. And just five million years ago, glacial deposits formed inside these depressions.http://www.msnbc.msn/id/7209308/ Some valleys on Hecates show a parallel drainage pattern.
