How were the long winding canali channels on Venus formed?

The long, winding canali channels on Venus were likely carved by lava that possessed very low viscosity and erupted at sustained, high rates of discharge.1

These meandering features are distinct from other volcanic landforms on the planet, such as shield volcanoes or pancake domes. While some channel-like features on Venus, such as sinuous rilles, may have resulted from collapsed lava tubes, the canali are notable for their remarkable length—sometimes extending thousands of kilometers—and their consistent widths. In some areas, these channels appear to flow uphill, which suggests that significant crustal deformation occurred after their formation, altering the original downward slopes of the surface.1