Edinburgh, Ind. ? A large oak tree dug up last summer in a gravel pit could be 6,000 years old or more and might have been entombed by a glacier during the last ice age, scientists say.

Researchers at three universities, including Hillsdale College in Michigan, are awaiting radiocarbon test results to pinpoint the age of the tree, which a southern Indiana dredge operator found under 40 feet of sand and gravel.

Scientists at Hillsdale, Purdue University and Hanover College are studying pieces cut from the logs last month.

Anthony Swinehart, an associate professor of biology at Hillsdale, said the tree’s age won’t be known until the results of a radiocarbon dating test are available in a couple of weeks.

Based on how deep the tree was buried, he and others estimate its age at 6,000 years. But it could be much older – perhaps up to 30,000 years.