New fault found north of Las Vegas

U.S. Geological Survey scientists have discovered a new thrust fault less than 30 miles north of Las Vegas.

The discovery came as the USGS mapped the Las Vegas Valley as part of a survey to help understand how groundwater flows and surface rock and soil features are altered by developers. There is little or no danger the fault could contribute to an earthquake, scientists said.

The report, released Monday at the International Association of Hydrogeologists meeting at the Riviera hotel-casino, said the fault is located in the Las Vegas Range near Gass Peak.

The fault hasn't moved in 60 million to 150 million years, a period known as the Mesozoic era. The latest thrust fault occurred at the end of the period, before earth entered its present geologic cycle, said USGS geologist Scott Lundstrom, one of several authors.

Southern Nevada's mountains and valleys are complex. Their features that were shaped by earthquakes millions of years ago are constantly changing due to erosion and flooding.

The USGS discovered the latest fault in an area previously unmapped.

Thrust faults deform many of the mountain ranges in Nevada, which is part of the country known as the basin and range.

Other thrust faults are located west and northwest of the Las Vegas Valley.

The most famous thrust fault belt is called the Keystone fault zone behind the Red Rock Canyon area.

The closest thrust fault zone to the new fault is located in Macks Canyon, northwest of Las Vegas.

Thrust faults heave blocks of rock from deep within the earth. In 1994 a thrust fault in Northridge, Calif., rocked the area with a 6.7 magnitude temblor.

The Northridge quake killed 72 people and caused about $25 billion in property damages.

The Northridge fault system lies 25 miles northwest of downtown Los Angeles.

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