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Question

The diagram below shows the formation of a volcanic arc. This arc was formed as a result of an oceanic plate moving underneath a continental plate in a subduction zone.

Image courtesy of USGS
Volcanic eruptions result in magma rising from the interior of Earth toward the surface. Lava is magma that reaches the surface of Earth. Magma and lava cool to form solid rocks that contain minerals from deep inside Earth. These rocks include metal ores, which are rocks that contain metallic minerals (such as copper, gold, silver, lead, and zinc).

Based on this information, which of the following is most likely to be true?
A.
The distribution of metallic minerals on Earth is uneven and depends on the geologic processes that occurred in the past.
B.
The distribution of metallic minerals on Earth cannot change over time because volcanic activity does not occur any more.
C.
The distribution of metallic minerals on Earth is evenly spread across all continents because geologic processes occur uniformly.
D.
The distribution of metallic minerals on Earth cannot be predicted due to the inconsistent formation of these minerals.

Answer 1

Based on the information provided about the formation of volcanic arcs, the behavior of magma and lava, and the formation of solid rocks that contain metallic minerals, the most accurate statement is:

A. The distribution of metallic minerals on Earth is uneven and depends on the geologic processes that occurred in the past.

This statement recognizes that varying geologic processes, such as volcanic activity, subduction, and plate tectonics, lead to an uneven distribution of metallic minerals across different regions of the Earth.