Egypt's Pyramids Packed With Seashells

April 25, 2008 -- Many of Egypt's most famous monuments, such as the Sphinx and Cheops, contain hundreds of thousands of marine fossils, most of which are fully intact and preserved in the walls of the structures, according to a new study.

The study's authors suggest that the stones that make up the examined monuments at Giza plateau, Fayum and Abydos must have been carved out of natural stone since they reveal what chunks of the sea floor must have looked like over 4,000 years ago, when the buildings were erected.

"The observed random emplacement and strictly homogenous distribution of the fossil shells within the whole rock is in harmony with their initial in situ setting in a fluidal sea bottom environment," wrote Ioannis Liritzis and his colleagues from the University of the Aegean and the University of Athens.

The researchers analyzed the mineralogy, as well as the chemical makeup and structure, of small material samples chiseled from the Sphinx Temple, the Osirion Shaft, the Valley Temple, Cheops, Khefren, Osirion at Abydos, the Temple of Seti I at Abydos and Qasr el-Sagha at Fayum.

X-ray diffraction and radioactivity measurements, which can penetrate solid materials to help illuminate their composition, were carried out on the samples.

The analysis determined the primary building materials were "pinky" granites, black and white granites, sandstones and various types of limestones. The latter was found to contain "numerous shell fossils of nummulites gen." At Cheops alone, "(they constituted) a proportion of up to 40 percent of the whole building stone rock."

The findings have been accepted for publication in the Journal of Cultural Heritage.

Nummulites, meaning "little coins," are simple marine organisms. Shells of those that lived during the Eocene period around 55.8 to 33.9 million years ago are most commonly found in Egyptian limestone. Fossils for the organisms have also been unearthed at other sites, such as in Turkey and throughout the Mediterranean.

When horizontally bisected, a nummulite appears as a perfect spiral. Since they were common in ancient Egypt, it's believed the shells were actually used as coins, perhaps explaining their name.

Fossils for ancient relatives to sand dollars, starfish and sea urchins were also detected in the Egyptian limestone.