Observations on the Geology of the United States of America

advantages aggregates alluvial America animal appears banks basin beds blue boundary cause changes classes of rocks clay climate coal considerable consists contain continues course covered decompose decomposition depositions direction distance divided earth easily east edge effects equal Europe examined extensive falls favourable feet fertile formation frequently gneiss granite gravel greatest grey wacke gypsum heat hills hornblende Hudson hundred iron island kind Lake land less light lime limestone limits manure masses matter miles Mississippi mixed moisture mould mountains nature navigation nearly necessary north-west observations occupies origin particles passes perhaps places position primitive primitive rocks probable produce properties proportion quantity range rapid red sandstone relative remains result rich ridge rivers rounded running sand secondary side situation slate soil springs strata stratification substances surface tains thick thin tion tolerable transition United vallies vegetable washed whole winds