Nature of the Narmada-Son Lineament

Abstract Critical examination of the several sections along the lineament from Handia to Barwaha have led to the identification of ten major and several minor faults in the area. They constitute a wrench system. The largest Badel-Dhasar-Ajnaskhurd fault is a primary first order right lateral wrench fault typically associated with the second order right-handed and the third order right lateral wrench faults. The Barjar-Bhadlipura fault is interpreted as a complementary first order left lateral wrench fault. The Badel-Dhasar-Ajnaskhurd and Barjar-Bhadlipura faults represent a first order set of conjugate shears. This would mean that the first order regional stress direction had WNW-ESE orientation. Folds related to the wrench faults have developed in the Precambrian rocks of the area. The most important Badel-Dhasar-Ajnaskhurd fault of the area around Chandgarh forms part of the Narmada-Son lineament. The Narmada-Son normal wrench fault steeply dipping towards south and Pachmarhi-JabaJpur normal fault dipping towards north constitute a graben structure. The Narmada-Son lineament has existed since late Archaean and has got rejuvenated from time to time.