Owens Valley Field Trip Oct 23-25, 1999
Leader: John Alderson

Meeting place at Red Rock Canyon. Nick in background.

Fossil Falls
10-15,000 years ago, sediment-filled glacial meltwater from the Owens River carved a gorge, including fossil falls, through this lava flow. Today, the falls itself is the fossil.

Fossil Falls. Shawn and Bruce on top. Nick on bottom.

Alabama Hills
These are just the tip of a deep escarpment. East of the hills is 9000 feet of alluvium caused by a long history of faulting that formed the main graben in Owens Valley.

Union Wash, Inyo Mountains, with Owens Valley in the background. John got a flat tire here.

Climb up ravine to find 240 million year old ammonoids in the Union Wash Formation.

Morning in the Sierras. Looking toward Mt. Whitney from Big Pine.

Devil's Gate. John using body english to explain the folding.

Spectacular folds in Devil's Gate

Papoose Flat road, Inyo Mountains

Long Valley Caldera
View east of highway 395 looking towards Lake Crowley. Formed about 700,000 years ago after a volcano erupted. After the magma chamber under the volcano emptied, the roof collapsed, forming the 10 by 18 mile caldera. The ash from the eruption formed the Bishop Tuff, which covers about 450 square miles.

Mono Lake with tufa towers
With Southern California agreeing to take less water, these towers will eventually be underwater (where they originally were).

Looking for freshwater springs in Mono Lake. Pinnacles of calcium carbonate form at the site of these springs and may eventually form underwater tufa towers.

Watching our step on the shores of Mono Lake

Panum Crater
Example of a crater-dome couplet. Dated at about 630 years ago.

Shawn touching the obsidian in Panum Crater

John, Bruce, Shawn, and Nick in Panum Crater.

Obsidian Dome (formed around 1040 AD)

Close up of obsidian on Obsidian Dome. The grey rhyolite cooled quickly to form the black volcanic glass (obsidian).