How many grooves does a quarter have on its circumference?

The Valles Marineris is located along the equator of Mars, on the east side of the Tharsis Bulge, and stretches for nearly a quarter of the planet’s circumference. The Valles Marineris system starts in the west with the Noctis Labyrinthus, proceeds east to Tithonium and Ius Chasmata, then Melas and Ophir Chasmata, proceeding to Coprates Chasma, then Ganges, Capri and Eos Chasmata, finally emptying out into an outflow channel composed of chaotic terrain and finally Chryse Planitia. Most researchers agree that Valles Marineris is a large tectonic "crack" in the Martian crust, forming as the planet cooled, affected by the rising crust in the Tharsis region to the west, and subsequently widened by erosional forces. However, near the eastern flanks of the rift there appear to be some channels that may have been formed by water or carbon dioxide.