Figure 4 - Mars ridge

Merged IRB image of a narrow FSR with a pointed top (pinnacle ridge) and a meander.
Merged IRB image of a narrow FSR with a pointed top (pinnacle ridge) and a meander. The pointed top may show that this FSR has been eroded heavily for a long time until only a narrow peak remains, or it may be that only a narrow part of the original river infill has been preserved.
HiRISE Image: ESP_067439_1505 NASA/JPL/University of Arizona