Arkose sandstone is characterized by a relatively high content of which mineral?

Arkose sandstone is characterized by a relatively high content of which mineral?

• A. Quartz
• B. Feldspar
• C. Clay minerals
• D. Micas

Answer: (D)

Arkose sandstone is defined by its high feldspar content. This mineral richness results from rapid erosion of nearby feldspar-rich granitic rocks, so the grains preserve a large amount of feldspar before extensive chemical weathering can break them down into clays. Quartz is present but not dominant, and clay minerals are kept low because chemical weathering hasn’t progressed far enough to convert much feldspar into clay. Micas can occur, but they don’t define arkose the way abundant feldspar does. So the characteristic feature is a substantial feldspar fraction, distinguishing arkose from other sandstones with more quartz or clay.

Arkose sandstone is defined by its high feldspar content. This mineral richness results from rapid erosion of nearby feldspar-rich granitic rocks, so the grains preserve a large amount of feldspar before extensive chemical weathering can break them down into clays. Quartz is present but not dominant, and clay minerals are kept low because chemical weathering hasn’t progressed far enough to convert much feldspar into clay. Micas can occur, but they don’t define arkose the way abundant feldspar does. So the characteristic feature is a substantial feldspar fraction, distinguishing arkose from other sandstones with more quartz or clay.