Codicil to the geophysical expression of selected mineral deposit models [unknown]

W. D. Heran
1994 Antarctica A Keystone in a Changing World   unpublished
Geophysical methods can play an important part in the search for obscure or hidden mineral deposits and can optimize the selection of drilling-targets. The geophysical models follow a similar format given in Bulletin 1693 and retain the same alphanumeric model numbers for the deposit types. The geophysical model format, briefly summarizes the geologic characteristics, given in Bulletin 1693, gives the regional scale geophysical expression, the deposit scale characteristics, physical property
more » ... hysical property values of the deposit and host rocks, remote sensing characteristics and an extensive reference list. The physical properties covered include, density, porosity, magnetic susceptibility and remanence, seismic velocity, electrical properties, optical properties, thermal properties, and radioelement content. The quantitative values given for each deposit model are usually in-situ measurements and not laboratory or drill core values. The physical property values for many host and cover rocks are contained in the introductory section of OF 92-557. The reference list contains what the author considered the more relevant publications, and the reader may use it for further detail. Illustrations, some from the literature, showing typical responses of various methods over deposits are given for each model. This report contains three new geophysical models which cover six of the Cox and Singer models and one revised geophysical model. The geophysical models may in some cases cover several related geologic models lumped together due to the similarity of geophysical signatures or lack of data on which to separate them geophysically. The models presented here are:
doi:10.3133/ofr94174 fatcat:3lyemtelyrcqpcvjhokgnvolii