The relationship of lode shape to wall‐rock structure in the southern half of the broken hill orebody

Abstract

Examination of the layering adjacent to the orebody in the Zinc Corporation, New Broken Hill Consolidated, and Broken Hill South mine workings and leases suggests that much of the layering observed in contact with the lode is a direct result of deformation and metamorphism. The layering in the “pelitic” gneisses is described and its stratigraphic significance is discussed. The contacts of the orebody are broadly concordant with the layerings described and the geometry of the layering and the orebody shape define two southward‐plunging folds. These folds are equivalent to the Group 2 folds defined by Hobbs (1966) for the northern end of the orebody. The plunge reversals in the orebody folds are attributed to subsequent deformational movements associated with a retrogressive phase of metamorphism.