sedimentary

Kaibab Limestone

Calcitic limestone, predominantly calcium carbonate (CaCO₃)

AI-generated identification · may be incorrect

Typically cream, tan, or gray, with a dull to slightly crystalline luster; Mohs hardness 3, specific gravity about 2.3–2.7. It commonly shows thin bedding, weathered cavities, and reacts vigorously with dilute hydrochloric acid.

Identified August 14, 2026More sedimentary →

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Physical properties

Formation & geological history

Marine limestone deposited in a shallow Permian sea roughly 270 million years ago, later uplifted and exposed by erosion in the Grand Canyon region. The visible ledges are part of the Kaibab Formation, though exact identification from a landscape photograph is approximate.

Uses & applications

Used locally as dimension stone, aggregate, cement and lime feedstock, and architectural stone; attractive pieces may be collected as geological specimens, though ordinary outcrop material has little commercial value.

Geological facts

The Kaibab Limestone forms the uppermost major rim rock of much of the Grand Canyon and caps resistant mesas and cliffs. Its pale color contrasts strongly with darker underlying Paleozoic formations.

Field identification & locations

Look for pale, resistant ledges atop the canyon, carbonate texture, and acid fizz; fossils may occur but are not always visible. Common around northern Arizona and southern Utah; avoid collecting in protected park areas.