 Mount <unk> is composed largely of <unk> . However , the summit ridge consists of <unk> basement rock , which is Pre @-@ <unk> in origin and about 1 @.@ 7 billion years old . There are various igneous <unk> including <unk> , as well as " bands " of <unk> and <unk> . Unlike mountains of similar altitude elsewhere , <unk> lacks both a permanent <unk> and a prominent north @-@ facing <unk> , which can be attributed to its position amongst other mountains of similar height , causing it to receive relatively small quantities of precipitation . 
