Question

The stage of textual maturity of a clay-rich sandstone containing poorly sorted and angular framework grains is:

• A. Mature
• B. Supermature
• C. Immature
• D. Submature

Hint:

Immature sandstones have poorly sorted and angular grains, indicating minimal transport and weathering.

Answer 1

The Correct Option is C

The degree of textural maturity in sedimentary rocks refers to the extent to which the rock's particles have been weathered, sorted, and rounded. A mature sandstone typically has well-sorted, rounded grains that have been subjected to long-term weathering and transport. However, an immature sandstone, such as the one described in this question with poorly sorted and angular grains, indicates a young rock that has not been subjected to much weathering or transport.
- Mature (A) sandstones are well-sorted and consist of well-rounded grains.
- Supermature (B) sandstones are highly mature with very well-rounded and sorted grains.
- Immature (C) sandstones are poorly sorted and contain angular grains, reflecting a lack of weathering and transport.
- Submature (D) sandstones lie between mature and immature, but the description of poorly sorted and angular grains points more towards immaturity.
Thus, the correct answer is (C) Immature.