Focused on Mississippi: Ice Age Boulders

Focused on Mississippi

JACKSON, Miss. (WJTV) – Back in April, we were in a rock quarry in western Hinds County, looking at gravel that was deposited under the bluffs. Some of those rocks were boulder sized.

The rockers are now out front of the Mississippi Museum of Natural Science in Jackson. A few of them are limestone, and some slabs have fossils embedded in the rock. The fossils were formed in Mississippi back when this part of the country was covered by the sea.You’ll find this type stone on the surface in lots of places in the state.

Now, the other smaller boulders were found in rock quarries under the loess bluffs along the Mississippi River and at the east edge of the Delta. Under those hills is a deposit of ice age gravels and sand, punctuated by the occasional boulder. Obviously, something this large can’t roll along a river bottom like gravel, but they come from thousands of miles away. Geologist James Starnes said they hitched a ride. 

“They go well over a ton. They were carried here across the coastal plain by ice. The only way you can get a rock that large here is to raft it on ice, but these things came from literally thousands of miles away,” Starnes explained.

He has collected and studied gravel from the ice age deposits in west Mississippi for a long time. All of this gravel was brought here by a prehistoric Mississippi River as it drained the continent eons ago. At one time, it carried off melt water from ice age glaciers that came as far south as St. Louis. Chunks of ice would break off and continue down river and deposit hitch-hikers like chunks of boulders along the way.

“These are going to be on the lawn for a glacier interpretation in our roll in the ice ages,” said Starnes.

The gravel tells a story off a long ago odyssey; of being broken off bed rock shelves way up north and then rolling on the bottom of the Mississippi. In the case of the boulders, they were given a ride on a hunk of ice.

A few of these Mississippi ice age boulders are in front of the museum where you can get a close look at them. Signage will come later interpreting what they are.

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