Rock Type and Tectonic Setting Matching Solution

This question requires matching specific rock types from Group-I with their most likely corresponding lithospheric/tectonic settings of formation from Group-II.

Matching Rock Types to Tectonic Settings

• P. Boninite: This type of rock is characteristically found in the fore-arc regions of subduction zones, making it strongly associated with Island-arc settings. Therefore, P corresponds to 2.
• Q. Lamproite: Lamproites are ultrapotassic igneous rocks often occurring in ancient, stable continental cratons. They are typically linked to Continental anorogenic settings, which are stable, non-orogenic environments. Therefore, Q corresponds to 1.
• R. Phonolite: Phonolite is an alkali feldspathoid volcanic rock. While it can appear in various settings, it is commonly found associated with continental rifts and also in Intraplate oceanic settings, such as volcanic islands. Therefore, R corresponds to 4.
• S. Leucogranite: Leucogranites often form from the melting of continental crust, particularly in thickened crustal regions. They are frequently observed in Continental collision zones, like major mountain belts. Therefore, S corresponds to 3.

Conclusion: Correct Rock-Setting Pairs

The correct matches derived from geological understanding are:

• P - 2 (Island-arc)
• Q - 1 (Continental anorogenic)
• R - 4 (Intraplate oceanic)
• S - 3 (Continental collision)

This corresponds to the matching P-2, Q-1, R-4, S-3.