GES 190 Field Research: Late Summer 2008*

*You must enroll in GES 190 during the autumn quarter of 2008 in order to receive credit.

August 25 - September 15, 2006:
Quaternary faults of the Surprise Valley, NE California: Combining geological and geophysical mapping techniques
Instructors: Anne Egger and Jonathan Glen (USGS)

Collecting magnetic field data in Surprise Valley.

The Warner Range in northeastern California represents the active westernmost edge of the extending Basin and Range province. A young system of normal faults tilts and uplifts a series of Tertiary volcanic and volcaniclastic rocks. In the Surprise Valley, to the east of the range, several geothermal springs follow more enigmatic structures offset from the rangefront itself. The lovely town of Cedarville sits at the foot of the steep eastern escarpment and range-bounding fault. We will build on our earlier gravity, magnetic, and seismic data collection in the Surprise Valley by conducting detailed transects across the range-front fault in numerous locations to better constrain the geometry of the fault system. The course will be taught from lodging in the town of Cedarville.

This three-week class will teach students the basic steps involved in collecting and recording geophysical data in the field and the fundamentals of producing a geologic map and constructing geological cross-sections from this data. Students will map Quaternary faults on topo bases using tablet computers, collect gravity and magnetic data in transects across key geologic features, and possibly collect shallow, high-resolution seismic data. The goal is to produce several detailed cross-sections of the Surprise Valley Fault system along its length in order to better constrain the evolution of this major fault system.

Depending on student interest, other projects may involve mapping sections of the volcanic sequence exposed in the range or mapping a comparison fault just to the north in the Warner Valley.

Collecting gravity data

Tentative schedule
Tuesday, Aug. 26 : Depart Stanford for Cedarville, CA
Aug. 27 : An introduction to the regional geology, fault system, and previous work
Aug. 28 - Sept. 1: Mapping project I (TBD)
Sept. 2-3: An introduction to geophysical field methods
Sept. 4-9: Detailed transects across the faults using gravity, magnetics, and GPS
Sept. 10-14: Mapping project II (TBD)
Monday, Sept. 15: Return to Stanford
Early in fall quarter: 2-3 meetings to finish up