Aconcagua, South Face, a new route on the Southeast Buttress to 6000 Meters. To acclimatize Jean-Luc Bedouet, Jean-Marcel Dufour, Pierre Rave- neau, Dr. Bernard Vallet, Jean-Pierre Chassagne and his wife Francine from January 16 to 22 climbed to 5900 meters on the north face of Aconcagua by the normal route but were turned back by very bad weather. Then they turned to their main objective, a new route on the south face by the southeast buttress. They reached Base Camp at 4000 meters on January 29, but bad weather hampered reconnaissance. On February 4 they left gear from a camp at the foot of the southeast buttress at 4700 meters but had to wait for three days for the new snow to clear off the face. On February 8 Raveneau and Chassagne climbed two pitches in a couloir to reach the buttress crest, which they followed for two more rope-lengths. On the 9th they ascended their fixed rope, then traversed right to a snow couloir which they climbed for one pitch. On February 10 these two, joined by Dufour and Vallet, climbed three more pitches in the couloir to the top of the first buttress, past the junction of three couloirs; they went up the left one. On February 11 they again climbed their fixed ropes from the 4700-meter camp, climbed to the top of the main buttress at 5100 meters and continued up the lower east snowfield to join the 1966 Argentine route and then the 1954 French route. Their route had ascended between the other two. They then descended, leaving all their fixed ropes in place. (This information was kindly supplied by Chamonix guide Jean-Paul Chassagne.)