The correct combination of textural feature of magmatic rocks with corresponding petrological process is
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- Exsolution lamellae → Sub-solidus cooling
- Reaction rim → Eutectic crystallization
- Graphic intergrowth → Quenching of ultramafic lava
- Spinifex texture → Peritectic crystallization
The Correct Option is A
Solution and Explanation
Step 1: Understanding the textures and processes.
Exsolution lamellae form when minerals separate at lower temperatures in magmatic rocks, a process known as sub-solidus cooling. This process typically occurs after the initial solidification of the magma.
Step 2: Analyzing the options.
(A) Exsolution lamellae → Sub-solidus cooling: Correct — Exsolution lamellae form during sub-solidus cooling, as minerals separate during cooling.
(B) Reaction rim → Eutectic crystallization: Reaction rims form due to reactions between different minerals, not related to eutectic crystallization.
(C) Graphic intergrowth → Quenching of ultramafic lava: Graphic intergrowths occur in certain types of igneous rocks, but they are not directly linked to quenching.
(D) Spinifex texture → Peritectic crystallization: Spinifex texture is related to rapid cooling of ultramafic lava, not peritectic crystallization.
Step 3: Conclusion.
The correct answer is (A) Exsolution lamellae → Sub-solidus cooling.
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