Keith R. DeVries, an archaeologist and authority on the excavation of Gordion, the ancient Turkish city once ruled by King Midas of the golden touch, died on July 16 in Philadelphia. He was 69.

The cause was cancer, his family said.

From 1977 to 1987, Dr. DeVries directed the University of Pennsylvania’s dig at Gordion, where members of the staff of the Museum of Archaeology and Anthropology at the university have been at work since the 1950’s. Gordion is about 55 miles southwest of Ankara.

Dr. DeVries was an expert in Greek pottery and trade ware of the first millennium B.C. and was interested in the relationship between Greece and Anatolia in the Iron Age.

In recent work, he and others used pottery and artifacts to redate an early catastrophe in Gordion, which was believed to have been destroyed in Midas’s time, about 700 B.C. By coordinating stylistic studies of pottery with radiocarbon dating of seeds found in the same ground layers, the archaeologists concluded that the destruction probably took place between 800 B.C. and 825 B.C., or a full century before Midas, after which the city was rebuilt.

The study was published in the journal Antiquity in 2003, and “finally made the archaeology and chronology consistent, and brought sense to what had been unclear,’’ said Naomi F. Miller, an archaeobotanist and senior research scientist at the museum. Dr. Miller worked with Dr. DeVries at Gordion.

In the 1960’s, Dr. DeVries participated on digs at Corinth, Greece, and on Ischia, an island off Naples. In addition to examining pottery, he studied a type of decorated safety pin called a fibula, which has been recovered from excavations throughout the ancient world.

Keith Robert DeVries was born in Grand Rapids, Mich. He earned an undergraduate degree at the University of Michigan and his doctorate in classical archaeology from Penn in 1970.

He was named an assistant professor of classical studies at Penn in 1970 and an associate professor in 1974. Dr. DeVries was also an associate curator in the Mediterranean section at Penn’s museum.

He retired from teaching in 2004, but continued his research on Gordion and lived in Philadelphia.

Dr. DeVries is survived by two brothers, David, of Littleton, Colo., and Roger, of Lone Tree, Colo.

Throughout his career, Dr. DeVries deplored the looting of artifacts, which sometimes seemed to occur under the noses of the scholars who were uncovering them.

In a letter to The New York Times in 1973, he explained, “The preservation of exact proveniences could, in the end, reveal much about ancient commerce, which was, one hopes, more decent and aboveboard than the modern trafficking in antiquities.’’