Mt Rouse, an exctint volcano south of Penshurst in W. Victoria was a source for copious lava flows which followed pre-existing valleys and reached the coast 60 km to the south. Many typical features of drainage modifications are associated
with the lava flows. Stony rises are widespread and it is deduced that a lava tube mechanism was in operation to produce such long flows. A new date for the volcano is 1,8 m.y., which is inconsistent with ages of about 0,3 m.y. reported from basalts near Port
Fairy. The Mt Rouse flows serve as a useful market for distinguishing Pleistocene from older volcanoes in this region. (E.C.F.B.).
Volcanoes of the Tristan Group have varied physiography resulting from the interplay of repeated volcanic eruptions, coastal erosion and fluvial erosion. The geomorphic histories of the islands are more complicated than was described in earlier