Question

Which one of the following is related to porphyry Cu-Mo deposit?

• A. Host rock is pegmatite
• B. Forms due to first boiling process
• C. Occurs in rift settings
• D. Forms due to sulfur saturation

Hint:

Porphyry Cu-Mo deposits are primarily related to magmatic processes such as the first boiling, where volatiles are exsolved from magma, rather than sulfur saturation.

Answer 1

The Correct Option is B

Step 1: Understanding Porphyry Cu-Mo Deposits.
Porphyry Cu-Mo deposits are large, low-grade ore deposits that typically occur in association with volcanic arcs and are primarily linked to tectonic rift settings. These deposits are often hosted in granitic rocks, but they form primarily due to the first boiling process in magmatic systems.
Step 2: Analyzing the Options.
- Option A (Host rock is pegmatite) is incorrect because the host rocks are generally granite or diorite, not pegmatite.
- Option B (Forms due to first boiling process) is correct because the first boiling process, which involves the exsolution of volatiles from magma, is a key mechanism in the formation of porphyry deposits.
- Option C (Occurs in rift settings) is incorrect as porphyry deposits are more commonly associated with subduction zones and volcanic arcs rather than rift settings. - Option D (Forms due to sulfur saturation) is incorrect as sulfur saturation is not the main mechanism for porphyry deposit formation.
Thus, the correct answer is (B) Forms due to first boiling process.
Final Answer: \[ \boxed{\text{Forms due to first boiling process}} \]