The Hesperian Period
Seriously, what really happened out there....?
As the Noachian Period, the period of intense meteoroid and asteroid bombardment, was gradually wearing off it was beginning the mark/stage of the Hesperian Period. The Hesperian Period was named after the Hesperia Planum, a high plain in the lower latitudes of the southern hemisphere. It was noted for its high volcanic activity and it continued from one period to the next and its volcanic eruptions covered over Noachian craters in many parts of Mars. Most of the large outflow channels on the planet are from/of the Hesperian age.
The Amazonian Period is characterized by a low rate of cratering and continues to this day. This period is named after Amazonis Planitia, a low plain that is in the lower latitudes of the northern hemisphere.
Volcanic Activity has occurred throughout the Amazonian Period, and some of the large volcanoes that we see today on Mars are from the Amazonian Period as well. The youngest geologic materials on Mars, which includes the ice deposits on/at the poles are also from the Amazonian Period.