Rocks and Rivers

ancient Appalachian beauty become beds blocks bottom boulders broad building canyon carried carved caves changes clays cliff color Colorado coming covered cross crust crystals deep deposits developed distance earth east edge effective erosion explanation fact fall feet finally flood floor flow follow forces geological geologist give glacier gorge grains granite hard hills important interest iron known Lake land landscape lava layers limestone lower mass materials miles mountain move movements narrow natural ocean origin pattern Peak period Photo picture plain plateau present rain rainfall range result ridges River Rockies rocks rounded running salt sand seen side slope soft soil springs stand story stream surface Texas underground understanding United uplift valley volcanic walls waterfalls waves weathering wide winds