Abstract
It implemented gamma-ray survey as the geophysical exploration which detects a fault. Gamma-ray anomaly appears only near the fault plane. The occasion when doing measures for the different stratum, the older the period on the stratum is, the more the fracture width gets widely. The fault with the narrower fracture width is the more multitude. It is a small number as a fault with wide fracture width. The cumulation and power-rule are admitted as the regularity with fracture width. It deduced the number of the appearance and the occurring time on the active fault from the regularity with fracture width.
