APPRAISAL OF THE PARAMETERS OF THE LITHOPROBE ABITIBI-GRENVILLE SEISMIC-REFLECTION SURVEY

The 1990-1991 LITHOPROBE Abitibi-Grenville seismic reflection survey c omprises 989 km of regional data collected for crustal exploration and 81 km of high-resolution data collected for mineral exploration. A pr oper interpretation of the data requires an understanding of its limit ations; these are a function of the acquisition parameters. The vertic al resolution is similar to 38 m for the regional data and 15 m for th e high-resolution data. The maximum reflector dip that can be imaged i n shallow data is similar to 70 degrees, but deep data are biased towa rd subhorizontal reflections. The principal sources of noise are vibra tor truck noise, ground roll, and shear wave refractions. Powerline no ise is surprisingly important on some high-resolution lines. The seism ic signal penetrates to the Moho, revealing differences in Moho reflec tivity across the survey.