Giza's Limestone Foundation and Chemical Weathering

The Giza Plateau sits on Eocene limestone, a rock type that dates back tens of millions of years. Most people don't realize that limestone is a carbonate-based rock, which means it dissolves when exposed to acidic water. This is basic petrology, the study of rock composition. The bedrock also contains some dolomite, minor sandstone, and marl, but limestone dominates to considerable depths. That solubility matters more than most people think. When you understand what limestone does in the presence of acidic groundwater or rainfall over long spans of time, you start asking different questions about erosion patterns, subsurface weathering, and the age of features carved into that bedrock.