Question

A metapelite is composed of muscovite + quartz + K-feldspar + kyanite mineral assemblage. If the muscovite and K-feldspar show solid solution between 'Na' and 'K' end-members, the minimum number of components that defines this metapelitic assemblage is ............. (In integer)

Hint:

When solid solution occurs between two end-members in a mineral, only one component is needed for that mineral in the assemblage, even if there are two end-members.

Answer 1

Step 1: Identify the components involved.
- Muscovite (solid solution between Na and K)
- Quartz
- K-feldspar (solid solution between Na and K)
- Kyanite
Step 2: Analyze the solid solution behavior.
Since muscovite and K-feldspar show solid solution between Na and K, we consider that muscovite can have two end-members (Na and K), and similarly, K-feldspar has two end-members (Na and K).
- Quartz does not exhibit any solid solution, so it is a single component.
- Kyanite is also a single component.
Step 3: Calculate the total number of components.
- Muscovite has 2 end-members (Na and K) → 1 component.
- Quartz → 1 component.
- K-feldspar has 2 end-members (Na and K) → 1 component.
- Kyanite → 1 component.
Thus, the total number of components is: \[ 1 (\text{muscovite}) + 1 (\text{quartz}) + 1 (\text{K-feldspar}) + 1 (\text{kyanite}) = 4. \] Final Answer: \[ \boxed{4} \]