Benchmark 4C
The Physical Setting: Processes that Shape the Earth
Grades K-2, page 72

Chunks of rocks come in many sizes and shapes, from boulders to grains of sand and even smaller.

The most closely related standard is at a higher level of sophistication.

NSES Content Standard D 
Earth and Space Science: Structure of the Earth system 
Grades 5-8, page 160 
Soil consists of weathered rocks, decomposed organic material from dead plants, animals, and bacteria. Soils are often found in layers, with each having a different chemical composition and texture.