Geological Prospecting

To track down useful minerals or other substances below the ground the geologist gathers all information already known about the area to be explored. Next, he or she maps this geologically, noting surface clues like faults and gangue minerals including quartz. Then the geologist can bring to bear any of a battery of tests. Geochemical tests analyze rock and other samples for trace elements that may lead the geologist to a major ore body. Geophysical tests include the following. Geiger counters or scintillation counters detect radioactive substances such as uranium. Gravimeters reveal variations in the density and identify the composition of underlying rocks.

Magnetometers indicate buried iron ores. Because iron is often found with sulfides, magnetometers may lead indirectly to non-ferrous metals, too.

Electrical surveys show certain ores affecting natural ground currents related to the Earth's magnetic field.

Seismic surveys test for various deposits, including oil, gas, and coal. Seismic surveying involves setting off explosions or vibrations that send shock waves down into the ground and timing their return from surfaces that bend or bounce them back. The speed of their return indicates the depth and nature of the rocks below.

All these prospecting methods merely hint at what lies underground. Only exploration can prove an ore is actually there and rich and big enough to be worth mining. If prospecting gives encouraging results, exploration follows. This means drilling sample cores or digging trial trenches to find out if development would pay.

(David Lambert “The Field Guide to Geology”, Cambridge University Press, 1998)

Find the answers to the following questions.

1. What are the stages for a geologist to find useful minerals or other minerals?

2. How can geochemical tests help geologists?

3. What equipment do geophysical tests include?

4. Is there any difference between electrical surveys and seismic ones?

5. Can geological prospecting alone prove there should be oil and gas?

Draw a diagram of geological prospecting and describe it.

Situational game.

Two groups - TPU students and TSU ones. The major is “Oil Exploration”. Discuss methods, elements of petroleum prospect, equipment, stages and tests of geological prospecting to have the opportunity to intern in one of the international companies.

Use the following communicative formulae:

On the one hand……on the other hand

All in all……….

Summing it up………..

In short………

Perhaps (may be \ possibly)…

It seems so…

To some extend (degree)…

First of all…\ to begin with…

As a matter of fact…

I’m inclined to think…

Exercise 19. 9 Listen to the video lecture “Crude Oil”.

Before watching.

Date: 2016-01-14; view: 960