 The eroded Franklin Glacier Complex just to the southeast consists of dacite and andesite rocks that range in age from 3.9 to 2.2 million years old.Southeast of Franklin Glacier Complex, the Bridge River Cones comprise remnants of both andesitic and alkali basalt cones and lava flows.These range in age from about one million years old to 0.5 million years old and commonly display ice-contact features related to subglacial eruptions.