The development of cross hole seismic techniques and case studies

Abstract

This paper outlines the development of a cross hole seismic tomography package by The Broken Hill Proprietary Co. Ltd. (BHP), as a tool for mineral exploration and mine planning. The methodology of cross hole seismic tomography, field procedures, instrumentation, processing software, and field trials are described.Explosives are principally used as the source of seismic energy. A repetitive source, based on rapid hydrogen-oxygen combustion, has also been developed. Signals are detected by geophone-based detector strings, and recorded by a data acquisition system developed by BHP. Tomographic imaging is conducted by the Algebraic Reconstruction, Back Projection and Simultaneous Iterative Reconstruction techniques.Surveys have been conducted in a number of different geological environments, and include: lead-zinc, iron ore and manganese exploration leases and mines to locate mineralisation and overburden interfaces; underground coal mines to locate regions of mining induced stress; and open cut and underground coal mines to locate coal and overburden contacts. The results of these surveys are discussed.