Stanley assembled a team of specialists in terrestrial magnetism, anthropology, paleobiology, and geology to examine the core samples.
After a few years of study, the team confirmed the findings did indeed point to Rhakotis.
In addition to the 3,000-year-old lead, which was used for construction, the cores contained stone building materials from central and southern Egypt.
"There are signs of a flourishing settlement going back to Pharaonic times, but it's too early to say anything about it," Mohamed Abdel-Maqsud, an Alexandria expert from the Supreme Council of Antiquities, told the Associated Press.
Jean-Yves Empereur, director of the Center for Alexandrian Studies, said he had not yet read the findings and could not comment.
The city's bay, anchored by the island—now a peninsula—of Pharos, has long been known as a haven for sailors. The bay is even mentioned in Book Four of Homer's Odyssey: "Therein is a harbor with good anchorage, whence men launch the shapely ships into the sea. ..."
When Alexander arrived in 332 B.C., he apparently agreed with Odysseus's reasoning. His new Egyptian capital would be close enough to the Nile for southern travel, but far enough away that seasonal flooding wouldn't be a problem.
Ptolemy I, Alexander's political heir, built the nearly 500-foot (152-meter) Lighthouse of Alexandria on Pharos, one of the Seven Wonders of the Ancient World.(See an illustration of the lighthouse.)
The lighthouse served as both a beacon and a symbol of Alexandria's greatness until a pair of earthquakes sent it tumbling into the bay 1,600 years later. Alexandria today is a breezy Mediterranean city of five million people.
The next step for researchers will be unmasking the culture and people of Rhakotis, now the bay's earliest known inhabitants.
"Were they seamen, agriculturalists, traders?" Stanley said. "We don't yet know."
Free Email News Updates
Sign up for our Inside National Geographic newsletter. Every two weeks we'll send you our top stories and pictures (see sample).
SOURCES AND RELATED WEB SITES