Definição: An isolated hill with steep sides and a small flat top, smaller than mesas and plateaus. Buttes are formed by erosion when a cap of hard rock, usually of volcanic origin, covers a layer of softer rock that is easily worn away. This hard rock avoids erosion while the rock around it wears down.
Definição: A habitat that is in or on a body of water containing low concentrations of dissolved salts and other total dissolved solids (<0.5 grams dissolved salts per litre).
