The Mojave's Cima Volcanic Field 

Geologist Alexander Schriener describes the methods that scientists use to determine the age of volcanic rocks, and the difference between volcanos and cinder cones. Thanks to radiometric dating scientists determined that the first eruption at Cima Volcanic Field occurred about 7.5 million years ago. Eruptions continued at the rate of about one every 100,000 years. Black Tank - the youngest cindercone in the Cima Field erupted just 11,500 years ago. Filmed at the Cima Volcanic Field in the Mojave National Preserve. For more information contact: robertmarcos2@gmail.com