Granitic rocks contain

Analyze the question: The question asks which minerals or elements make up granitic rocks. Granite is an igneous rock, so we need to recall its composition.

Concept: Granite is an intrusive (plutonic) igneous rock made mainly of quartz, feldspar, and mica. It is the main rock of the continental crust, which is often called SIAL:

• Si = silica
• Al = aluminium

By contrast, the oceanic crust, made mostly of basalt, is called SIMA:

• Si = silica
• Ma = magnesium

The core is called NIFE, from nickel and iron.

Solution:

1. Granite is the typical rock of the continental crust (SIAL layer).
2. SIAL means it is rich in silica and aluminium.
3. Check the options: • A. Silica and aluminium: correct, this matches SIAL. • B. Silica and iron: iron is more typical of basic rocks like basalt and of the core (NIFE), not of granite. • C. Magnesium and copper: copper is not a main rock-forming mineral in granite. • D. Copper and bauxite: bauxite is an ore of aluminium formed by weathering, not a component of granite.

Answer: The correct option is A. silica and aluminium.

Tip: Link the words "granite" and "continental" to SIAL. Link "basalt" and "oceanic" to SIMA. Remembering these pairs helps with many questions on the structure of the earth.