The
old rock faces of the Black Canyon tell of changes which have
occurred over a period of two billion years. The surrounding
mesas are capped with cliffs and rocky spires, evidence of
violent volcanic eruptions some 30 million years ago. These
formed the West Elk Mountains to the north. Later volcanic
episodes to the south formed Southwestern Colorado's scenic San
Juan Mountains, and spewed vast quantities of ash over this
area.
The
Gunnison River readily cut down through this volcanic matter,
but below lay the tough, ancient rock that has been exposed in
Black Canyon. This canyon lends the fjord-like character to
Morrow Point Lake's steep, rock walls. Crystal Lake is also
steep-walled. Blue Mesa's lake bed formed in less-resistant
volcanic mudflow materials. As these eroded beneath solidified
volcanic layers, spires formed.
The
old rock faces of the Black Canyon tell of changes which have
occurred over a period of two billion years. The surrounding
mesas are capped with cliffs and rocky spires, evidence of
violent volcanic eruptions some 30 million years ago. These
formed the West Elk Mountains to the north. Later volcanic
episodes to the south formed Southwestern Colorado's scenic San
Juan Mountains, and spewed vast quantities of ash over this
area.
The
Gunnison River readily cut down through this volcanic matter,
but below lay the tough, ancient rock that has been exposed in
Black Canyon. This canyon lends the fjord-like character to
Morrow Point Lake's steep, rock walls. Crystal Lake is also
steep-walled. Blue Mesa's lake bed formed in less-resistant
volcanic mudflow materials. As these eroded beneath solidified
volcanic layers, spires formed. 