JGP 438 OPTIONAL EXPERIMENTS SECTION (Done as last experiment)

1. To complete the lab program of 5 exercises, all students must (jointly with their lab partners) choose and complete one of the experiments listed below. Because most of these experiments involve equipment, and we have only one or two sets of each, parties must reserve the lab period during which they will do their work. The sign up sheet is on my office door (MP501).
2. Lab interviews - Students are reminded that the lab mark is based on their lab reports and on an interview held in the last two weeks of term in which the experiments and their reports will be discussed. Details about this will be posted soon. Interviews are conducted individually, and you must sign up for a scheduled time. You should bring your marked lab reports to the interview.

Choices for optional experiments

1. Gravity and magnetic modelling and interpretation using the "MAGIX" computer program.(4 setups available)

This demonstrates how gravity or magnetic profiles across anomalous features can be interpreted quantitively. Specific instructions are in the handout entitled

P2 Gravity and Magnetic Modelling/Interpretation

Background information is in the Lab Manual: - Gravity and Magnetics chapter (already distributed)

2. E1: - Electrical Depth Sounding (2 setups available)

This technique is used a good deal in engineering and environmental studies to study the layering of shallow strata. Clays, sands and gravels, impermeable igneaous metamorphic rocks, etc., have very different abilities to conduct electricity, and this makes it possible to differentiate and locate the formations by electrical measurements made on the earth's surface.

The field technique is demonstrated on a small scale model in the lab. Data from the experiment and archive data from field surveys are interpreted using the ResInverse computer program.

Read the section Electricity Theory p1-5 in the E and EM Lab notes for background.

3. E2: Resistivity/Induced Polarization Survey of a Laboratory Model (1 setup available)

This is a scale model simulation of mineral exploration using the resistivity/IP method. An electrical profiling survey is carried out on the surface of a water + sandbox which contains some hidden objects. This is somewhat more labour intensive than the other choices.

The Instruction sheet is entitled:- A resistivity and Induced Polarization Survey of a Laboratory model

Read the E and EM Lab notes Electricity Theory (P1-5) and Electrical Conduction in Rocks (P1-7) sections for background

4. Detection of Highly Conductive Mineralization using the Horizonal Loop Electromagnetic (HLEM) Method.(1 setup available).

See the Exercise instructions EM1: - Horizontal Loop EM Method

A scale model study is made of how the HLEM system responds to known conductive objects. Then the model system is used to detect and delineate conductors hidden inside an enclosed space that simulate sulphide mineralized formations.

Read the E and EM Lab Notes Electromagnetic Exploration Methods (P17-29) and A Model of the Horizontal Loop EM Method (P30-31) for background.