Rocks and Rivers

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