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miércoles, 4 de febrero de 2009

Geological Feature Key To Finding, Protecting Tombs



A 42-year-old method for finding water, monitoring pollution and helping with tunneling may also be a way to locate and protect tombs in the Valleys of the Kings and Queens and other burial sites in Egypt, according to Penn State researchers.

The idea that fracture traces could bare some connection to the rock cut tombs found in Egyptian valleys came to Katarin A. Parizek as she toured Egypt. K. Parizek, the daughter of Richard R. Parizek, professor of geology and geo-environmental engineering at Penn State, is a digital photographer, graphic designer and geologist. In 1992, on a Nile cruise to the Valley of the Kings near Luxor, she recognized the geological structures.

"Many of the tombs were in zones of fracture concentration revealed by fracture traces and lineaments," says K. Parizek, an instructor in digital photography. "I knew that these fractures were what Dad used to find water or to plan dewatering projects."

Fracture traces are the above-ground indication of underlying zones of rock fracture concentrations. In 1964, Laurence H. Lattman and R. Parizek published a paper on fracture traces that indicated where increased weathering and permeability occurred and where people could drill wells more efficiently. These fracture traces can be between 5 and 40 feet wide, but average about 20 feet, and can be as long as a mile.

An initial study in Egypt showed that some tomb passages and resting chambers were aligned along these fracture zones, suggesting that the builders knew that these locations had less resistant rocks and easier digging. The Parizeks report today (Oct. 22) at the annual meeting of the Geological Society of America in Philadelphia, on recent work in the area.

More extensive surface and subsurface mapping confirmed the idea that the builders knew what they were doing. The tomb builders placed the entrances to their tombs in valley bottoms or receding depressions on the cliffs where the crumbling stone would hide the tombs. These tombs, built between 1500 and 1000 B.C., usually have a long entry hall leading to a burial chamber. They may have additional rooms for equipment and provisions and other storage areas. Tomb walls are often plastered and painted. The tombs are usually built sloping downward or actually have vertical shafts. To date, 63 tombs are identified in the Valley of the Kings with tomb 63 located in February 2006.

"Katarin predicted that the location of still to be discovered tombs might be determined using the fracture-trace method," R. Parizek said. "The discovery of KV-63 showed the correlation between tombs and fracture traces."

While locating previously unidentified tombs is a worthy endeavor, perhaps even more important is preserving the tombs. Many of these are open for viewing by the public and are the responsibility of the Egyptian Ministry of Antiquities. Maintaining the tombs is a complex and complicated job.

While it does not often rain in the desert, when it does, water pours off hills and runs over the land and into the wadis -- valleys. Paving of parking lots, roads and paths to allow tomb visitors increases the flooding. Even though the Egyptians build barriers at the tomb entrances, water often flows into the tunnels causing irreversible damage to the tombs.

The open entrances, however, are not the only way water enters the tombs. Water finds the fracture concentrations beneath the fracture traces and seeps into the ground. If tombs are built along or below the traces, eventually water insinuates itself through the fractured rock and enters the tombs. Water can ruin even undiscovered, unopened tombs in this way.

"If we can map the fracture traces and their associated fracture zones above and below ground, then we can see how to divert water so that it not only misses the tomb entrances, but also bypasses the permeable areas of the traces," says R. Parizek.

Water entering tombs through the fractured rock also causes major damage to roofs and pillars in the tombs. The researchers note that even without water, the pillars and roofs are more unstable on fracture zones. With water, the limestone rock weakens and breaks off. Because of these rock stability problems, tombs are closed for fear of injury to visitors.

"What they need to do is channel water along the pavement, away from the pathways that otherwise lead into the tombs," says K. Parizek. "Keep flow away from the tombs."

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