A year of excavations along the Brunswick-Altamaha Canal has given David Patterson a better understanding of what 20,000-year-old Brunswick would have looked like.
While Patterson, a professor at the University of North Georgia, has been leading excavations along the canal since 2005, he sought the permission of the Federal Law Enforcement Training Center and Glynn County Commission last year to work on public land. The county commission gave him permission to continue his work for another year on Thursday, and he said he’s likely to use it.
Patterson said during an interview with The News in June 2018 that, based on their findings, he believed Brunswick would have been 50 miles from the sea and mostly comprised of grassland.
It would have been crisscrossed by rivers and broken up by stretches of woods. Humans wouldn’t begin leaving their mark in North America for another few thousand years.
Megafauna like Columbian mammoths, giant ground sloths, giant land tortoises, longhorn bison and saber-toothed cats would have shared an ecosystem with a variety of smaller reptiles, mammals, birds and insects, he said in 2018.
Much of the tests he and his team have conducted on fossils found along the canal over the last year support that, he said.
“We’ve been doing a lot of analyses back up in Dahlonega at the University of North Georgia,” Patterson said Thursday. “... The biggest thing we’ve done over the past year, a lot of the fossils we’ve found we’ve been doing a diet analysis on.”
A diet analysis involves looking for clues as to what a prehistoric animal ate, he explained, and knowing an animal’s diet can shed a lot of light on its environment and daily life.
“Unlike the modern environment, these animals eat a lot of trees and grasses, not just grasses like they’ve been characterized in the past,” Patterson said. “The two main large mammals we’ve worked on are the mammoth fossils and the giant bison.”
A lot of mammoth and bison fossils were found in Florida, and a diet analysis on both had yielded some new information, he explained.
“Because we’re farther north, bison and mammoths were concentrating mostly on trees,” Patterson said.
Of course, they aren’t just interested in the large, extinct ancient creatures. While the mammoth may be interesting, other animals may give a better idea of what the immediate area around its fossil looked like.
“Mammoths and bison had huge home ranges and ranged over a vast territory, but a rodent may only eat one thing, one kind of grass,” Patterson said. “So we can look at that and say ‘This area could support them.’”
In addition to understanding their environment, Patterson said the excavation team has also been hard at work trying to pin down the rough time period the bones they’ve found were buried.
He estimates they’re around 20,000 years old, but further tests were needed to settle the question.
“With every paleontology dig, geology has to come before the paleontology,” Patterson said.
Fossils are best preserved when a carcass is covered quickly after death. Radiocarbon dating is the go-to method of determining a fossil’s age, but Patterson said they also plan to run sand found with the fossils through a test called optically stimulated luminescence.
“It allows you to analyze the last time a grain of sand has been exposed to light. What that allows us to do is figure out exactly when a fossil was buried,” Patterson said. “... I think it will strengthen our conclusion that these fossils were buried 20,000 years ago.
“Are the sediments, the sand, basically, that the fossil occurs in, is it the same age as the fossil?”
If it is the same age, that opens another door. If the sediment surrounding the fossil is the same age as the fossil itself, then it is representative of the soil composition of 20,000-year-old Brunswick. That fact, in itself, helps paint a clearer picture of that ancient environment.
“We can use the type of soil present at the time to shine a light on what the landscape looked like,” Patterson said. “You’re creating a model for interpreting what the landscape looked like. A lot of paleontological digs look at the fossils but not how they got there. We’re trying to understand the ecosystem. Why are some plants here and others there? Why did certain animals die here or there? We’re trying to understand it at this big ecosystem level.
“We’ve been able to figure out so far that this was a very complex system of rivers draining to the ocean 20,000 years ago, and these fossils are all associated with this ancient network of river channels.”
Currently, he’s working on, among other things, identifying different sand types, relationships between sand types and how they came to mix.
For the soil analysis, he called in an expert, Chris Seminack, a coastal geologist with the Institute for Environmental and Spatial Analysis at the University of North Georgia.
“Stuff is becoming more clear. With every hole we dig, the more we understand about the ancient ecosystem,” Patterson said. “Prior to really trying to investigate this stuff, people thought that when you dig in the ground it’s just sand. But when you do these really high-resolution analyses of grain size, et cetera, you get this really great picture of the complex, complicated environment that these animals lived and died in.”
Working in this area has been very informative, Patterson said, and he plans to continue excavating in Brunswick and along the coast for a long while.
Funding hasn’t been a problem, and cooperation from local authorities and landowners has been a non-issue, he said.
“I’ve been really impressed by the support of the Brunswick community,” Patterson said. “Landowners have been extremely helpful, FLETC has been extremely helpful. It’s made my job a lot easier because everyone has been so open and seemingly interested in learning the history of the area.
“... I’ve met with (County Engineer) Paul Andrews (and) the chairman of the (county commission, Mike Browning), and they’ve been very supportive. Paul has been great talking about the history of the canal, he’s been very excited about it.”
He hopes to be able to publish all his findings within the next few months.