A SUGGESTED SOLUTION TO THE BLIND ZONE PROBLEM IN SHALLOW EXPLORATIONSURVEYS

The blind zone in exploration using the refraction method is one which exists in practice and therefore has to be carefully considered in th e solution of any shallow exploration studies using the seismic refrac tion method. This case study presents problems encountered due to the occurrence of a blind zone during a tailings dump evaluation in which the refraction method was employed and suggests a solution to the prob lem. The solution works well in situations where the velocity of the h idden layer approximately equals that of the overlying layer. The resu lts of depths computed using the method were compared with those obtai ned from drilling and they yield very satisfactory reliability.