Formation of the American Southwest (including Nevada)

Basin and Range Geology

Hundreds of Millions of Years Ago The American Southwest was under water.Sediment piled creating layers of Sedimentary Rock. The Land was uplifted creating a flat plateau.

Plateau:very Flat land

15 million Years ago• The land begins to stretch. • Creates normal faults• Causing some fault block to sink.• High points = Ranges(mountains)• Low points = Basins (valleys)

RangeBasin

Where are the faults? Which direction is the land stretching?

This pattern is seen all over

the Southwest as North-South Running Basins

and Ranges

This is how Las Vegas Valley FormedWest side of Valley (Red Rock)

North-South Running Range

North-Southrunning Basin

More Evidence around town

Fault Blocks weather and erode overtime, so there are not always sharp drops

Las Vegas Alluvial Fansweathered fault blocks

Arial View of an Alluvial Fan