GEOL 492/692 - Applied Geophysics
Preparation for Field Exercise

Contents

Additional Resources


Objective and Setting

This spring break we investigate the shallow geophysical characteristics of the high-standing parts of the muddy and sandy V-Line canal bank within 2.5 miles west of the power plant at the Twenty Six Foot Drop, west of Fallon and of the rocky Truckee Canal bank within 1 mile north and south of the Bango Rd. bridge across the canal.

Please make sure the instructors (Louie or Huebner) have a copy of the the Geology department's emergency contact form that you have filled out recently. Amr Wakwak has copies and is distributing them.

Each participant must also read the permit application document, which explains what we have promised to do and not do. If anyone violates any of our promises, such as driving at more than 5 mph on the canal bank, we risk getting ejected from our field area.

Since we are close to home, on each of field day will leave at 7:00 AM from the top deck of the Whalen Parking Garage, and return there each night, probably about 7:00 PM. I will have parking permits so students driving to the Whalen Garage Monday through Thursday will be able to park there all day. Students may bring their own vehicles to the field area, but they must still meet us at 7:00 AM at the Whalen Garage, or 7:30 AM at Pioneer Way (west end) and US 50 west of Fallon, and they must do so entirely at their own risk.

Each student will not need to bring any camping or cooking equipment for our local work, only daily food and drink. You may also need any medications, toilet paper, etc., since we will only go into town at lunch time for a restroom break. Many of the items on the personal equipment list are still necessary. Be prepared especially for wildly variable weather conditions.

We may delay our work during fierce storms, but we will have to make up storm days (or for equipment failure) on Friday and Saturday. If in doubt about the weather, come that day to the Whalen Garage at 7:00 AM anyway, and Louie will be there to let you go home if the weather is too awful. Or call Louie's cell phone at 6:00 AM.


Assignment

Each team of two or three students will take primary responsibility for one of the 5 types of measurements we will take in the field:
  1. Seismic Refraction and ReMi: Mahesh, Kristin, Sean
  2. Seismic Reflection: Bryce, Mayo, Danny
  3. Gravity and Theodolite: Betsy, Annie, Sue
  4. Magnetics: Wendy, Dan
  5. Resistivity and EM: George, Scott
Each team is responsible for developing a detailed plan for how we will prepare the instruments, conduct the field experiment, and analyze the results. We will coordinate the surveys so everyone gets experience with each of the methods. The seismic teams can work with Louie to prepare, and the other teams can work with Huebner.

Guidelines for proposing the survey plans are below.

Finished plans should include complete and detailed checklists of every item that will go to the field, data sheets and/or software disks, instrument operation instructions, maps showing proposed survey locations, and schedules for work by each team.

Designing a Survey Plan

Each team should develop a detailed plan in writing to guide us in mobilizing, performing the fieldwork, and sharing and analyzing the results. In essence, a complete plan would answer all of the questions below. Starred questions need to be answered by Mar. 7. More questions, related to each type of survey, are found in the sections below for the various surveys. Please work with me, other Department faculty, and the other teams to answer the questions, one by one. You aren't expected to be able to answer them all by yourself. The written survey plan will naturally help you write your field report.

Mobilization (all methods)


Fieldwork (all methods)


Interpretation (all methods)

References

Telford et al., our textbook.

Compton, 1962, Manual of Field Geology, chapters 2, 3, 4, 11.

Dobrin and Savit, 1988, Introduction to Geophysical Prospecting, pages 3-8 and as noted below:


SURVEYING

Instrument overseers and information source: John Bell, Geoff Blewitt, Nevada Bureau of Mines and Geology Ref: Compton, chapters 6, 7, 8.

GRAVITY

Instrument overseers and information source: R. Karlin, G. Oppliger Ref: Dobrin, pages 498-503, 505-506, 528-535, 547-553, 561-586, 602-604, 613-621.

RESISTIVITY SOUNDING

Instrument overseer and information source: R. Petersen; also G. Oppliger, and Ken Taylor at DRI; . Ref: Dobrin, pages 750-768, 815-831, 833-842.

MAGNETIC

Instrument overseer and information source: G. Oppliger Ref: Dobrin, pages 633-678, 685-710, 723-733.

SEISMIC

Instrument overseers and information source: J. Louie Ref: Dobrin, pages 58-68, 78-90, 450-459, 473-482.