Image is from a scanning electron microscope. The stippled lines indicate in schematic fashion the dip and the frequency of seismic reflections. Dark blue lines denote seismic reflection profiles and the dashed red line shows the northern limit of sedimentary cover. White lines denote seismic reflection profiles. The Slave-Rae collision.
White lines show seismic reflection profiles.
The prominent layering of the syn-rift deposits between 10 and 30 km depth are shown clearly. Note the strong positive contrast of the rift valley to its surrounding rocks. The reason for the positive anomaly was not understood until the results of our studies in the Great Lakes - the large volume of dense volcanics in the rift valley causes the anomaly. Vibroseis sound service source with geophone spread. A Vibroseis crew at work in Ontario.