Scientists converge at Snowmass fossil dig
June 24, 2011
SNOWMASS VILLAGE -Heading into the final week of a fossil dig at Ziegler Reservoir near Snowmass Village, a group of 27 scientists has joined a rotating excavation crew that has recovered more than 4,000 Ice Age bone specimens since mid-May.The fossil count stood at 4,056 on Friday, according to the Denver Museum of Nature & Science, which is pushing to recover fossils in an area of the reservoir where construction work on a dam is scheduled to begin after the July 4 weekend.”While much of our activity has centered around salvaging fossils from the core of the dam site, we are now entering a phase of intense scientific investigation about the origin of the Ice Age lake and its history,” said Dr. Kirk Johnson, leader of the excavation team, in a press release. He is vice president of the Research and Collections Division at the museum.The scientists are among 37 experts from 15 institutions in the United States, Canada, Spain and England who are involved in the project and whose work will make the most of the site’s scientific potential, according to the museum. Their on-site activities include collecting cores of sediment from the ancient lake bed, studying the sediment that fills the ancient lake, making high-resolution scans of in-place fossils, and collecting various samples for analysis.”Sediment cores are a very important way for us to sample the complete sequence of lake sediments and preserve them for future research,” Johnson said. “They are a critical piece of the science that can be archived and studied for climate information such as temperature changes and drought.”A small drill rig, operated by scientists from the U.S. Geological Survey offices in Lakewood, Colo., is drilling 20 to 30 feet into the sediment and pulling cores that are 2 inches in diameter so scientists can access and study all the sediment layers that accumulated at the site. The core samples will first be studied in Denver and then move to the University of Minnesota, where they will be permanently stored at the National Lacustrine Core Facility. Funded by the National Science Foundation, the facility was established in 2000 to archive high-quality sediment cores from lakes all around the world and make them available for research. In addition, a team from the Colorado Water Science Center is collecting LIDAR ground laser scans of select fossils. These scans are precise to within a few millimeters and will allow scientists to reconstruct parts of the site with high-resolution 3D models.The scans are particularly useful for mapping areas where numerous fossils occur together, and the information may shed light on the burial history of the fossils, the museum explained. For example, the team has located a portion of the ancient lake shoreline, which contains a partial mastodon skeleton interlocked with driftwood logs that are up to 35 feet long. The LIDAR scans provide a detailed map of the site that allows the dig teams to document the site rapidly before continuing their excavation.The team of scientists is also gathering thousands of samples from the site, to study fossil pollen and spores, insects, plants, and the character and chemistry of the lake sediment. These samples will provide critical information about the ecology and climate of the ancient landscape, the museum said.Also on the scene is a National Geographic crew. The National Geographic Society intends to feature the fossil find in National Geographic magazine and in a National Geographic-NOVA special on PBS within the next year.