Among the many important discoveries made during the mapping of the Lacolle, Sutton, and Memphremagog quadrangles for the Geological Survey of Canada in recent years was that of a conglomerate formation whose outcrop traverses the middle of the Lacolle quadrangle from north to south, passing through the village of Lacolle. This formation was mentioned, but not described, in a recent paper by the senior author.1 The outcrop (Fig. 1) was mapped by the junior author.
For constructive criticism regarding the age and correlation of this formation, thanks of the authors are due Dr. G. M. Kay, to whom the senior author is also indebted for calling attention to an error in Figure 2 of his previous article, in which the Lacolle conglomerate is shown in the geological cross-section as basal to the Chazy, instead of basal to the Stony Point.
Except for its southeast corner, the Lacolle quadrangle lies . . .