Research on the Earth's glaciers found that when the volcanoes under the glaciers start to erupt, they will quickly produce steam streams, explosively penetrate the ice layer, release ash into the upper air, and produce zeolite, sulfide and clay. Recently, people have discovered that these minerals have also been detected on some round flat-topped hills on the surface of Mars, and they are widely and abundantly present. Therefore, it is speculated that the early Mars was covered with ice sheets, where there had been more volcanic activities.
To get the above conclusion, the premise that needs to be added is that the three types of zeolite, sulfide, and clay are unique substances that are only produced after volcanic activity under glaciers.