Natural Resources and Plate Tectonics
INTRODUCTION
Since 1940 the demand for natural resources has increased tremendously. Not only have the
well-developed western nations continued to increase consumption, but new demands of the
developing third-world nations have been added. In fact, resource suppliers have been
strained to meet demand at affordable prices.
Metals are among the most sought-after resources. The Earth’s crust contains quantities of
metals far in excess of the foreseeable need. However, most are in concentrations too low
for profitable removal. As a result, there has been an intensive search for new ore deposits,
but few important discoveries have been made in recent years. New exploration methods
are needed. Recognition of the role of plate tectonics in the formation of metal deposits
has provided some guidance. The mapping of plate boundaries and the occurrences of ores
has shown that certain metallic ores are located along these boundaries. These areas are
called metallogenic provinces. From these studies geologists have found that copper
porphyry and other ores are associated with subduction zones.
In this exercise you will use the relationship between subduction zones and copper deposits
to locate promising sites to search for new orebodies.
OBJECTIVES
When you complete this exercise you should be able to:
1. recognize the relationship between subduction zones and copper porphyry deposits.
2. suggest logical areas to search for new orebodies.
3. identify former plate boundaries according to the metal deposits associated with them.
4. understand the predictive value of plate tectonics theory.
MATERIALS
World Subduction Zones map on transparent paper; Copper Porphyry and Molybdenum
Deposits map; red colored pencil, blue colored pencil and a pencil.
PROCEDURE
1. In red pencil, at subduction zones copper deposits are found above the diving plate not
far from the plate boundary.
2. On the Subduction Zones map draw zones about one-half cm. wide where copper deposits
are likely to be found. (Where land occurs.)
3. Place this map over the Copper Porphyry Deposits map so the continental margins
coincide.
4. Complete the Student Work Sheets.
Name _________________________________Date_________________________ Period________
Natural Resources and Plate Tectonics
Student Work Sheet
1. Do the copper ore deposits coincide with the metallogenic provinces you drew on the map?
Yes No
Circle one.
2. Near the western boundary of the North American plate the copper deposits are located
on the: diving plate; overriding plate.
Circle one.
3. At the subduction zones in the western Pacific the copper deposits are found on the:
diving plate; overriding plate.
Circle one.
4. List two areas in North and South America where it would be logical to search for new
copper deposits and explain your choices.
____________________________________________________________________
____________________________________________________________________
5. List three areas in the western Pacific which might be worthwhile investigating for
copper orebodies. _____________________________________________________
____________________________________________________________________
____________________________________________________________________
6. What geographic feature is associated with the copper deposits of Russia? _____
_______________________________Circle the type of plate boundary that probably
existed there at one time: mid-ocean ridge, transform fault, subduction zone.
7. Based on the features associated with Russia’s copper deposits; suggest a similar area in
Eurasia to seek new copper orebodies.
8. As a plate dives into the mantle its sediments and bedrock are melted by the extreme
heat and pressure. Different melting points and other physical properties tend to
concentrate each metal at a particular depth. Therefore, magmas rising above a diving plate
are enriched with different metals according to their distance from the subduction zone.
On your Subduction Zones map use a blue pencil to indicate a zone in North America where
you would expect to find molybdenum deposits. How does this compare with the locations of
actual molybdenum deposits on the map? ______________________________________
____________________________________________________________________