Monument Basin from the air, looking north to Junction Butte and Grand View Point. The spires result from wind and stream erosion removing the surrounding, less resistant rock. Jointing within the formation aids in the erosion process.
Compound cross-stratification (cross-bedding) in Esplanade Sandstone. Man at right gives scale to these complexly developed beds, which have been produced by stream or wind currents blowing sand across a surface on which sand was accumulating. Scouring of the stream floor by turbulent flowing water may create small depressions in the channel deposits, which later will be refilled by inclined beds.
Glacial moraine holding lake at the base of the Granadier Range. Large blocks of glacially derived material were dumped at the down-valley side of the glacier when it was active. The moraine dammed melt waters from the receding glacier to form a lake.
Glacial striations on bedrock. Rocks embedded in the bottom of the glacier served as "tools" that scratched the bedrock over which the glacier moved. These features are useful indicators both of the former presence of glaciers and of the direction in which the glacier moved.