QAPF Diagram and Rock Classification

This video tutorial introduces the QAPF diagram, a tool for classifying phaneritic rocks based on mineral percentages. It explains the diagram's structure, how to use it to classify rocks, and the conditions under which it applies. The tutorial also briefly mentions other diagrams for different rock types, such as pyroclastic and extrusive rocks.

What is the primary purpose of a QAPF diagram?

• To classify rocks based on mineral percentages

• To identify the color of rocks

• To determine the age of rocks

• To measure the density of rocks

Which type of rocks is the QAPF diagram specifically used for?

• Sedimentary rocks

• Metamorphic rocks

• Feritic rocks

• Volcanic rocks

What does the 'Q' in the QAPF diagram stand for?

• Quartzite

• Quartz

• Quarry

• Quicksand

Which mineral is represented at the bottom point of the QAPF diagram?

• Quartz

• Plagioclase feldspar

• Alkali feldspar

• Felids or foids

What is the term used for the percentage of each mineral in a rock?

• Density

• Mode

• Texture

• Composition

If a rock has 35% quartz, where would it plot on the QAPF diagram?

• Near the right

• Near the top

• Near the bottom

• Near the left

In the example given, what is the rock classification if it has 35% quartz and 50% plagioclase feldspar?

• Granite

• Gabbro

• Monzo granite

• Diorite

What is a key requirement for a rock to be classified using the QAPF diagram?

• It must contain fossils

• It must be sedimentary

• It must have a phaneritic texture

• It must be volcanic

Which diagram is used for classifying pyroclastic rocks?

• QAPF diagram

• Ternary diagram

• Pyroclastic diagram

• Mineralogy diagram

What is the main difference between the QAPF diagram for intrusive rocks and the one for extrusive rocks?

• The shape of the diagram

• The minerals represented

• The texture of the rocks

• The method of plotting