The frontal riser of the first pediment surface (P1) is the most recent fault scarp or diluvial platform;at the foot of pediment P1 outcrops the fault.

• 第1级麓原面（P1）的前缘陡坎为最新断层崖或洪积台地，断层崖的坡脚为断裂带地表出露位置；