Geology of Mars of the dichotomy places a significant constraint on theories of its origin. Straddling the dichotomy boundary in Mars's western hemisphere is a massive volcano-tectonic province known as the Tharsis region or the Tharsis bulge. This immense, elevated structure is thousands of kilometers in diameter and covers up to 25% of the planet’s surface. Averaging 7–10 km above datum (Martian "sea" level), Tharsis contains the highest elevations on the planet and the largest known volcanoes in the Solar System. Three enormous volcanoes, Ascraeus Mons, Pavonis Mons, and Arsia Mons (collectively known as the Tharsis Montes), sit aligned NE-SW along the crest
Erebor Mons Erebor Mons Erebor Mons is a mountain on Titan, the largest moon of the planet Saturn. It is located near Titan's equator, between 4-5° south and 35-36° west, centered on , in the western part of Quivira region. It is 40 km across, more than 1 km high and has lobate flow features to its north and east. It is probably a cryovolcano. Erebor Mons is situated about 470 km to the north-northeast of a larger cryovolcanic construct, Doom Mons. Erebor Mons is one of the highest known mountains of Titan, but it is not readily discernible on radar or