Application of high-resolution seismic-reflection techniques in Champlain Sea sediments near Lachute - Saint-Benoît, Quebec

High-resolution seismic-reflection techniques have been tested and applied at several sites northwest of Montréal where thick Quaternary deposits were suspected. This work was conducted as an aid in determining the three-dimensional structure of the Holocene and Pleistocene stratigraphy in the area for ongoing NATMAP and groundwater studies. Initial test seismic arrays indicated areas with substantial thicknesses of overburden above bedrock, several reflecting horizons interpreted as distinct lithological contacts, and high-frequency reflection signals providing good vertical resolution. From the initial testing results, specific survey lines were selected, and common mid-point reflection techniques were designed to optimize the rate and quality of data acquisition. A modified form of ‘centre-spread’ shooting was adopted, that not only provided adequate stacking (12 fold), but also allowed improved estimates of subsurface velocities required for seismic processing. An example of processed seismic section shows excellent stratigraphic detail. 2001-D6 B. Benjumea et al. 1 CURRENT RESEARCH RECHERCHES EN COURS 2001 Article Article Titles Titres Purchase Information Information pour acheter 1 GSC Quebec, Québec 880, chemin Sainte-Foy, Sainte-Foy (Québec) G1V 4C7