Geology 15                                                                                          West Valley College

Geology of California                                                                                  Robert Lopez

 

Study Questions 11: The Basin and Range – Mojave Provinces

 

Read pp. 125-140 in Harden and browse the remaining portions of Chapter 7.

 

1)      In what direction is the Basin and Range faulting migrating in California, what kind of faults are most common, what is the stress environment, and what may be the ultimate cause of Basin and Range faulting?

 

2)      How much extension has there been in Death Valley, and approximately what is the present rate of extension?

 

3)      Sketch a graben and half graben.

 

4)      Briefly discuss the 1872 Owens Valley earthquake (p. 128).  Mention its magnitude and the geological significance of the fault (i.e. Range Front Faults).

 

5)      What two major faults form the NW and SW boundaries of the Mojave Desert?

 

6)      Describe the general geographic extent of the Basin and Range province (e.g. east to Utah, south to Sonora, see fig. 7-2 in Harden).

 

7)      What are fault scarps?

 

8)      What are detachment faults (p. 132)?

 

9)      What are Metamorphic Core Complexes?  What do we call these in Death Valley (p. 135)?

 

10)  What is mylonite?

 

11)  What is the origin for recent volcanism along range-front faults in the Basin and Range province (p. 137)?

 

12)  What does the Basement Geology of the Basin and Range/Mojave provinces tell us about California’s geologic history (two events)?

 

13)  What does the Pahrump Group tell us about California’s geologic history?

 

14)  What do the Noonday/Ibex Dolomites and Jonnies/Sterline Quartzites tell us about California’s geologic history?

 

 

 

California Deserts / Basin and Range Wrap-Up

 

“Don’t miss” points in Death Valley National Park:

 

Dante’s View.  Finest view of the Valley and Panamint Range.  Best in morning.

 

Titus Canyon.  Drive through a deep canyon in the Amargosa Range.  Off-road.  Need a high clearance vehicle but not four-wheel drive.

 

Ubehebe Crater. A maar volcano formed by steam explosions a few thousand years ago.

 

A few of the sights to see in the Lone Pine area of the Owens Valley:

 

Whitney Portals Road.  Drive to an elevation of ~8300 ft. and the Mt. Whitney trailhead.

 

Alabama Hills.  Thousands of rounded granite outcrops and boulders.  Site of many famous movies and favorite location for photo workshops.

 

Owens Dry Lake and the Alabama Gates of the Los Angeles Aqueduct.

 

Grave site of the 1872 earthquake victims and the fault scarp (see Sharp and Glazner below for location of scarp).

 

Manzanar.  Internment camp for Japanese-Americans during World War II.  If your go, be sure to go to the cemetery in the back of the camp.

 

Recommended Readings:

 

Walking California’s Desert Parks: A Day Hikers Guide, by John McKinney

 

Geology Underfoot in Death Valley and Owens Valley, by Robert Sharp and Allen Glazner

 

Deepest Valley: A Guide to Owens Valley, Its Roadsides and Mountain Trails: by Genny Smith.  A classic on the area but may be out of print.

 

Basin and Range, by John McPhee.