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Marketing and University Communication UW-Green Bay, CL 815 2420 Nicolet Drive Green Bay, WI 54311-7001 (920) 465-2626 E-mail: hildebrs@uwgb.edu Last update: 4/7/08 |
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In
the News Archive - Year:
March 31, 2008 Excavators find prehistoric bones at Maribel Caves By Kristopher Wenn
The bones, discovered at the park's New Hope Cave between January and February, have been dated to between 5,600 and 5,800 years old, said Dr. John Luczaj, an associate professor of earth science.
"We believe there are older bones yet to be discovered further into the cave from data collected during the exploratory excavations done during the 1990s," said J.D. Skattebo, a Manitowoc resident and chairman and founder of the Friends of Maribel Caves, in an e-mail.
Luczaj said it is unknown what animal the two-bone vertebrae came from, but it may have been a small mammal "bigger than a bat but smaller than a woodchuck." The bone vertebrae each were less than a centimeter in length, he said.
Skattebo said he and fellow excavators discovered the bones beneath flow or float stone, which is a formation created by calcium carbonate flowing into the cave from spring melt water. The bones are the first to be dated from New Hope Cave, he said.
Luczaj said his preliminary conclusion from the finding is that the cave's sediment is at least as old as the bones. The cave's age is probably similar to the age of other caves in Northeastern Wisconsin, he said.
The cave's sedimentary history helps researchers piece together what has happened in the entire cave system, he said.
"If you can identify the fossil, you can understand what the ecology and climate was here at different points in time," Luczaj said, noting researchers of Brussels Hill Pit Cave in Door County have discovered fossils of rodents that no longer exist in the state.
"We can infer things about climate if we understand how old the deposits are and what was the environment that these organisms lived in," he said.
"Our goal is to learn and understand why the caves are still there, how did they fill, and when and why," said Skattebo. "We are also studying the groundwater interaction with the water table."
The bones discovered at New Hope Cave were radiocarbon dated by Beta Analytic Inc. of Miami. The bones were dated using collagen extracted from the bones, Luczaj said.
The radiocarbon dating was funded through a UW-Green Bay grant and with funds from the Wisconsin Speleological Society and the Friends of Maribel Caves.
He said he is planning to submit an application for another grant to radiocarbon date a shoulder blade bone that was discovered elsewhere in the park.
Luczaj said his long-range goal is to publish a scholarly article describing the cave's sediment history and characteristics.
Excavators will resume work on the cave either in May or June, depending on park conditions and the influx of water to the cave. Volunteers give guided tours of the caves during digs and by appointment, Skattebo said.
Skattebo said he hopes the bone discoveries spur public interest in fundraising, with county approval, for a proposed learning center at the park on the "broad range of topics" involving the cave's history.
The bone sample and data collecting has included a few area residents. But the cave restoration project includes many area residents, groups and organizations, he said.
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