Soil type comparisons for bearing and strength — identify the set of correct statements about composition, shear strength, and safe bearing among listed ground materials:

Introduction / Context:
Preliminary foundation decisions often rely on broad soil descriptions and expected engineering behavior. Knowing which loam has more sand or silt, and recognizing relative bearing capacities of common natural strata, helps in site reconnaissance and in evaluating desk-study data before detailed testing.

Given Data / Assumptions:

• “Sandy clay loam” indicates a clay loam with higher sand fraction.
• “Silty clay loam” indicates a clay loam with higher silt fraction.
• “Boulder clay” is a stiff glacial till with gravel/boulder inclusions and strong matrix.
• “Soft chalk” is weak, porous carbonate rock, often low in safe bearing without improvement.

Concept / Approach:

Textural names directly reference dominant fractions: sandy variants have relatively more sand; silty variants more silt. Stiff boulder clay typically has high undrained shear strength due to dense, overconsolidated matrix and gravel/boulder reinforcement. Soft chalk, due to its low density, fissuring, and crushability, usually provides lower safe bearing pressure unless improved or confined.

Step-by-Step Solution:

Verification / Alternative check:

Typical bearing-capacity tables list higher allowable pressures for stiff clays/tills and lower for soft chalk; agricultural soil texture triangles also support the fraction-based naming.

Why Other Options Are Wrong:

Choosing any single statement would omit other true facts; the question asserts multiple correct facts.

Common Pitfalls:

Confusing “clay loam” with “loamy clay”; assuming chalk is always strong rock (its softness and microstructure matter).

Final Answer:

All of the above