Right now due to the low viscosity of most lunar lava, Volcanic mountains were seldom created. Instead, basaltic lava flooded in larger areas, which became a lunar maria.
Lunar maria - is a large dark basaltic plains on earth s moon, formed by ancient volcanic eruptions.
The cause of the volcanic eruptions of the moon was due to second lunar atmosphere developed 3.5 billion years ago as a result, flooding a large crater is form mare Imbrium, a lava plain on the near side of the moon and moon's surface is covered with dead volcanoes in the year that we are standing right now the moon volcanoes does not erupt.