BATAN GRANDE, Peru — In an ancient tomb at the bottom of a deep shaft, Izumi Shimada has uncovered gold that looters failed to find. Finely tooled ornaments, recently exposed, peek out from the compacted dust of 10 centuries and gleam like sunshine breaking through clouds.
This cache was left by a little-known pre-Inca society called Sican or Lambayeque. So richly endowed were its burial sites near Batan Grande, in northern Peru, that the weight of Sican gold in today's collections and museums probably adds up to tons.
"In quantities of gold objects, there is nothing that matches it in all of South America, or perhaps in the Western Hemisphere," Shimada said. But because most Sican artifacts were dug up by looters, whose plundering sheds little archeological light, knowledge of the society's characteristics and accomplishments has been murky.
That is changing, however, with the work of Shimada, a Japanese archeologist with Harvard University's Peabody Museum, who has spent 13 years investigating the Sicans. His pioneering work has uncovered evidence of a complex and important society with astonishing skill in metallurgy and obsessive devotion to one fearsome deity.
Shimada's project at Batan Grande, recently shown to American journalists for the first time, is an example of how painstaking research is revealing the vast cultural and technological wealth of Andean societies that flourished long before the Inca empire.
Another major project is expanding scientific knowledge of the great Tiwanaku empire, centered near the Bolivia-Peru border on Lake Titicaca. In northern Peru, Christopher B. Donnan of UCLA and Walter Alva of Peru's Bruning Archeological Museum have found revealing remnants of the Moche culture, which preceded the Sican here.
Over the centuries, the shifting constellation of Andean cultures produced much of the hemisphere's best pre-Columbian agricultural technology, architecture and stonework, metallurgy and metalwork, pottery and weaving. Many archeologists say the Incas, with their famous and far-reaching organizational skills, succeeded mainly in consolidating rather than surpassing the achievements of the cultures they succeeded.
Sican metallurgy is a case in point. Although the Incas made bronze from copper and tin, they did not change to the Sican method of mixing copper and arsenic after they conquered the Batan Grande area.
Shimada said the Sicans produced bronze for domestic use and export on "practically an industrial scale, with probably hundreds of smelters. There is no place I know of in the entire New World where you find in greater frequency the remains of metallurgical activities."
Among the remains is charcoal used in smelting. The small size of the charcoal pieces, Shimada said, indicates that the Sicans burned fallen branches from the scraggly, tiny-leaved algarrobo trees of the area rather than cutting the trees down. An algarrobo forest still covering much of the area was recently set aside as an ecological preserve.
The Sicans cast bronze tools and agricultural implements. They made sheet metal, Shimada said, "and not just a small amount, but large amounts and consistent. This metal, even by modern high standards, is well done."
For decoration, they plated bronze sheets with a thin veneer of gold or silver. "We don't know for sure how the plating was done," he said. Modern metallurgists have tried unsuccessfully to reproduce the process.
As he spoke, Shimada, 43, stood by the gaping mouth of a shaft dug 35 feet into the earth. At the bottom, workers meticulously cleaned loose dirt from the tomb's various parts. An eye-catching glitter of gold came from within the outline of an ancient box in the far corner.
"What we have is a cache of head ornaments, including four crowns," Shimada said. Near the gold were the bones of a young Sican in a sitting position, perhaps a sacrifice victim left as a guard.
The walls at the bottom of the shaft showed seven sealed entrances to what Shimada said were burial chambers for members of the Sican elite. Based on information gathered from veteran looters of other tombs, he said, more gold will be found in at least one of the chambers when it is opened.
It isn't the gold, however, that excites Shimada the most. This is the first shaft tomb of an elite Sican ever excavated by archeologists, and he expects it to yield a treasure of new information about the culture as well as more samples of its best art.
So far, work at different sites of Sican culture has indicated a complex society. "I think we are looking at at least four different social levels," Shimada said.