Description: From Waitt and Beget (1996): "Two domes of porphyritic gray andesite form conspicuous topographic bumps at altitudes 1025 and 910 m on the upper northwest flank, some 400 to 800 m northwest of the central summit-dome complex. The large West lsland debris avalanche (table 3 [in origincal text]) must have left a large crater including this area so the domes must be younger than about 350 yr B.P. (age of B tephra, table 2 [in original text]), though they precede the historic eruptions."