Dig supervisor Alton Briggs says the area offers a wealth of shards and other debris. "Wonderful stuff" unearthed by an archaeological dig on the Alamo grounds includes a glass arrowhead made from a Spanish Colonial wine bottle and the possible existence in the 1740s of another long barracks.

"They have found wonderful stuff. This arrow point is perfectly formed," said Pat Osborne, the city's historic preservation officer.

Osborne speculated that the rare arrowhead probably was crafted from a sacramental wine bottle, which must have struck the Indian craftsman as marvelous new ammunition material. Seven flint arrowheads were discovered early in the dig, which began three weeks ago.

An Austin archaeological team was commissioned by the Alamo's caretaker, the Daughters of the Republic of Texas, to carry out exploration of the area around the Alamo gift shop, where the group plans to expand the basement storage and dig a tunnel to a proposed freight elevator next to Houston Street.

Mark Denton, staff archaeologist with the State Antiquities Committee, said that when exploration of the area began, it was unknown whether any significant artifacts had survived the generations of Alamo tenants who had "churned up the soil."

"I never would have believed such extraordinary deposits from the mission period would be found," Denton said. Besides the arrow points, the finds include Indian pottery burnished in a technique learned from the Spaniards, he said. The earthen floors of a building dating back to about 1740 also were discovered west of the gift shop. The floors surprised archaeologists because maps of the period show open areas where the building used to stand.

"The Spanish missionaries were meticulous record keepers, so we can assume that this building was demolished before the Battle of the Alamo,"Denton said.

Two separate dirt floors about 6 inches thick mark the spot where the building once stood.

Alton Briggs, supervisor of the dig, said in a news release that the floors are separated by about 20 years, and the area between them offers a wealth of animal bones, pottery shards and other debris that can be fixed precisely in time by carbon dating.

"These artifacts answer some questions that we hadn't thought to ask, up until now," he said. Denton said the floors may have been part of a long barracks like the one restored by the DRT on what is now the west perimeter of the Alamo groundson Alamo Plaza. "There could possibly have been a granary in that location," he said.

All the artifacts will be put on display in the Alamo gift shop in a few weeks, said Marjorie Hardy, DRT Alamo Committee chairwoman.