Chapter 2: Birth of an Oasis
The Amargosa River wends its way underground from the Amargosa Valley to Badwater Basin in Death Valley. There it sinks into the ancient, Lake Manly aquifer.
Lake Manly was formed about 185,000 years ago. In the height of its glory, it filled Death Valley 600 feet deep, was about 11 miles wide, and 90 miles long. But it disappeared after the last ice age ended, leaving us with the shallow, non-potable pool of water we call Badwater Basin.
Much more ancient than Lake Manly is the subterranean unrest that has fumed in this area over many millions of years. It all started 400 million years ago, when the Farallon Plate, under the Pacific Ocean, decided to dive under the North American Plate. A war between the plates ensued, that still rumbles on today, contributing to California and Nevada’s many earthquakes, and the rise of the Sierra Nevadas.
It also led to chaotic fracturing of the ground below the Amargosa Valley. And this fracturing created a phenomenon that made this valley a hub of human life and civilization for at least a thousand years.
Millions of years ago, a strike-slip fault lifted a chunk of mountains near the present-day town of Amargosa Valley, Nevada, thousands of feet up, while forcing a similar chunk of earth to sink thousands of feet downward. The grinding action on both sides of this fault created a deep underground wall of polished and sealed rock, along a straight line, stretching over a distance of many miles.
The wall was impermeable to the flow of water. Meanwhile, north of this wall, glaciers formed and melted over many different ice ages. When they melted, the water pooled beneath the surface of the earth, into vast aquifers, or underground lakes. Water slowly trickled south from these lakes through subterranean rivers.
Some of these rivers met the polished, sealed wall of the strike-slip fault near Amargosa Valley. They could not penetrate the densely compacted earth, and had nowhere to go but up. And so, they percolated to the surface of the earth. Here they formed beautiful, crystal clear, artesian springs.
The springs overflowed, creating creeks and streams and rare, alkaline meadows. Grass, trees, and other vegetation grew and thrived. Wild animals were attracted to the water, and the area teemed with life. And over thousands of years, 29 species of plants and animals evolved that could be found nowhere else on Earth. Two of these species are now extinct, five are endangered, and seven are listed as threatened.
This is the latest installation of my series, The Amazing Amargosa. Come on back in a few days for the next installation, entitled, Chapter 3: Ash Meadows. Click here to read the previous installation. Click here, to start at the beginning.