1. Education

Stop 10, Lovejoy Basalt: The Setting

By

Stop 10 is at 39°27.636´N, 121°34.918´W, where route 70 dips into the Feather River valley. (more below)
Lava beds above a river
Photo (c) Andrew Alden, licensed to About.com (fair use policy)
We have crossed from the Coast Ranges to the Sierra Nevada and will begin seeing subduction-related rocks from much earlier periods. But here in the lowest foothills is a gently tilted surface marked by the 16-million-year-old Lovejoy Basalt, the same rock found at stop 6 on the other side of the Central Valley. When the lava was molten it flowed down a stream valley, but today that hard layer is preserved as a ridge, a situation that geomorphologists call inverted relief.

Day 1, Coast Range: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9

Day 2, Sierra Nevada: 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18

Day 3, Sierra Nevada: 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28

Day 4, Coast Range: 29 | 30 | 31 | 32 | 33

©2014 About.com. All rights reserved.