Karst Rock Weathering of The Great Pyramid of Giza

Abstract

The exposed stone blocks of soft carbonate rock, from which the pyramid is built, quickly develop a distinctive form and rock relief. The outer parts of the blocks are often undercut into overhangs. On their upper parts, a protective crust forms through rock dissolution and rapid recrystallization under the influence of occasional rain and seeping water, shielding the rock from wind erosion and dissolution. This crust, in turn, is dotted by small pits, whose bare surfaces remain exposed to wind erosion, allowing them to expand and grow deeper. In the lower sections, where the rock is fully exposed, wind erosion primarily carves out larger cups and channels. A thin crust may occasionally form over these sections, but tends to flake off quickly. This process suggests rapid karstification and the ongoing disintegration of the stone blocks.