Unusual breccias were noted at several places in the vicinity of Groundhog and Glacier Basins, about 13 miles east of Wrangell on the mainland of southeastern Alaska, in 1942 and 1943. They are similar in some respects to the clastic dikes in Colorado described by Burbank [see 1 of “References” at end of paper] and Haff [2], and to some explosion breccias in the Samoan Islands described by Stearns [3].