This Clementine image shows wrinkle ridges detected with SMART-1 in the Procellarum basin.

The wrinkle ridges are not distributed radially around the basin. Due to their location, they do not seem associated with mass concentration tectonics, but mostly are results of thermal and mechanical deformations resulting from volcanic activity - due to compression from basalt extruded by the lava. The Procellarum basin contains the youngest basalt found on the Moon so far, up to two thousand million years old.