Penn State researchers working at a granite rock quarry in Aswan, Egypt, said they have found a canal that could explain how ancient Egyptians transported large monuments to the Nile.

Elizabeth Walters, associate professor of art history, said she and other researchers have been working on the site for a few years. After making a presentation at the Second International Conference on Geology of the Tethys in March, they have just submitted their proposal to go back to the area and research further.

Embedded in the Aswan rock quarry, around the area where the canal was found, is an unfinished obelisk -- a tall, pointed monument made of a single stone.

The incomplete obelisk is more than 40 meters long and has been estimated to weigh more than 1.5 tons, according to the researchers' presentation.

The unfinished obelisk can be dated back to 15th century B.C., which is in the Egyptian 18th dynasty -- a time when many of these obelisks were being constructed, Walters said. Ancient Egyptians left the obelisk in the ground because of a fatal flaw that occurred when they were about to take it out, she said.

"From my standpoint, that's great. It leaves people to try to figure out how they did it," said Shelton Alexander, professor emeritus of geophysics.

Alexander said his work at the quarry consisted of using a seismic system to detect the presence of a canal, which a local investigator had told the team might be in the area.

He said the researchers placed devices in the ground that would detect seismic waves, then shot shells into the ground to trigger the seismic system. From this information, Alexander said they could determine the composition of the sub-surface.

Walters said Richard Parizek, professor of geosciences and geoenvironmental engineering, worked at the site to detect a canal by monitoring the ground's temperature.

Walters said Parizek drilled a hole in the ground, put a plastic pipe in a hole and used it to measure heat and water, generating observations from the change in temperature.

"If it's cooler, you can say that's where the ancient canal was," she said.

After the tests verified the presence of an ancient canal, there were still questions left unanswered, Alexander said.

"How it was used is still a matter of speculation," he said. "It's hard for me to believe [obelisks] would float in a canal."

The canal slants downward a couple of degrees, Alexander said. He said the ancient Egyptians could have used the slant of the canal and the mud lining the bottom of it to more easily push the obelisk along.

While trying to trace the canal to the Nile, the tracing stopped at a fence that marked off the border of the site, the outskirts of which Alexander said are off-limits to the Penn State team.

Walters said there are apartment complexes, paved areas and a graveyard around the quarry area.

Alexander said they would be able to work next to roads or through open areas, but they would not be able to trace the canal through the existing buildings.

He said another way it would be possible to trace the canal would be to use satellite imagery, which would be a faster approach to the research.

Walters said the researchers have submitted a proposal to continue their work in January, hoping they can eventually trace the canal to the Nile.