Legend has it that Menehune built the Pihana heiau in one night using stones from the banks of the 'Iao Stream below the sacred site.

The old stories do not say how long ago that happened, but using modern radiocarbon-dating techniques, anthropologist Michael Kolb of Northern Illinois University said he has determined the ancient temple was erected in the early 13th century, at the start of a 500-year span of heiau construction that peaked during times of great political and social change.

Most of what is known about Hawaiian civilization prior to European contact was handed down through oral histories that lack accurate dates. Kolb said his research, the most extensive of its kind, was able to determine a range of eras when Maui's network of heiau was built and often rebuilt.

During a 12-year field study, Kolb and his research team identified and examined 40 heiau, excavating portions of the sites to collect the charcoal remains of fires the Hawaiians used to clear vegetation and from ovens and fire pits. While radiocarbon dating of the samples placed most of the temple construction in the late 1500s and early 1600s, Kolb said the findings revealed that some heiau were built much earlier.

He said his data show that 13 temples were built or modified during the 14th century, while seven temples — including Pihana and the much larger Pi'ilanihale in Hana — were constructed as early as the 13th century.

Pihana, part of the Haleki'iPihana State Historical Site in Wailuku, is the oldest known temple site on Maui, with Kolb's median radiocarbon date placing its construction at about 1214. His research indicates the temple was renovated at least seven times, a common practice as new chiefs came into power.

"It was a common phenomenon for conquering chiefs to assimilate in many ways their new territories. They would purge the local chiefs and put in their own people, and also do the same thing with religious temples: rededicate them to their own gods. Oftentimes they wouldn't build new ones, but go in and modify and adds wings to existing temples.

"Liholiho, Kamehameha's son, did this when Kamehameha conquered Maui and O'ahu" in the late 1700s and early 1800s.

Kolb said his study also identified four periods of peak construction that correlate with important social and political trends discussed in the oral histories of the Islands: a span of years in the 13th century when chiefs were gaining economic and political status and becoming more involved in religious rituals; a period in the 14th century when chiefdoms were expanding in East and West Maui during interisland conflict; the busy period in the late 1500s and early 1600s following unification of the island by Pi'ilani; and Kamehameha The Great's conquest of the island chain.

"Monuments are usually utilized to express political, religious or economic power, and so they tend to be used during periods of conflict or conquest. They are used as territorial markers and to display the wealth of chiefs to impress enemies as well as loyal retainers," he said.

Melissa Kirkendall, the Department of Land and Natural Resources lead archaeologist for Maui and Lana'i, said she and some of her colleagues had long believed that a number of Maui's heiau were built well before the 1500s.

"To get such a large database of radiocarbon dating is invaluable. It's a great addition to our research," Kirkendall said.

Kolb said his study disagrees with some of the findings of archaeologist Patrick Kirch of the University of California at Berkeley, who announced in January 2005 that a newer technique of uranium-thorium dating of coral found at heiau sites suggested that many major Hawaiian temples on Maui were built within a 30-year span coinciding with Pi'ilani's rise to power.

Most of the coral samples used in Kirch's research were taken from the surface of heiau and may not reflect the period of original construction, Kolb said, since materials were recycled during subsequent alterations. He also said Kirch studied only seven temples at Kahikinui, Maui, and one on Moloka'i, yielding data that may not be valid for other areas.

In response, Kirch said that his research did not claim that no heiau were built before the late 1500s and 1600s, but rather that the period was a rapid phase of temple construction, which he said is in "good agreement" with Kolb's findings.

Peter Mills, who heads the Anthropology Department at the University of Hawai'i-Hilo, said the new research may not entirely put to bed the question of when Maui's temples were built, as there is some argument among scholars as to whether radiocarbon dating is accurate for the kind of research Kolb is conducting. He said the uranium-thorium method allows for more specific dating down to a span of decades, compared with centuries for radiocarbon dating.

"Radiocarbon dating has been a mainstay in archaeology for half a century and it is pretty accurate on the scale of centuries, but there are a number of factors that complicate the assignment of a specific calendar age to any sample," Mills said. "For example, if you date a piece of 'ohi'a, what you get is the date the 'ohi'a was growing, not the date it was turned into an artifact, and those two events could differ by several hundred years."

Kolb said his research also documented a shift in heiau function in the mid-1400s from the early construction of open-air temples used for ancestral worship to more elaborate enclosed structures used for sacrificial rituals at heiau dedicated to war gods, where he uncovered large quantities of pig bones.

The more elaborate, terraced temples were adorned with altars, oracle towers, offering pits, carved wood or stone images and enclosed wooden structures, he said. Thatched-roof buildings were often built nearby as shelters for chiefs, drum houses or oven houses where sacrificial offerings were prepared.

Kolb said he chose Maui as the study area because it has some of the best-preserved heiau in the state and enabled relatively easy travel between sites. There are about 120 known temple sites on the island, where the ancient foundations or other remnants can still be found.

Because of the Islands' isolation, Kolb said, Hawai'i is "an excellent test case for state development." He sees common threads between the construction of monumental architecture here and similar activities in other ancient societies such as the Mayans and Egyptians, who also built temples directly linked to economic, political and ritual trends.

His study will be published in the August issue of Current Anthropology.

Reach Christie Wilson at cwilson@honoluluadvertiser.com.