BLUE RAPIDS — Long before there were humans to see it, a sheet of ice plowed into northeast Kansas, so heavy that it pushed down the ground, so powerful that it dragged thousands of pink boulders from Minnesota, dumping them as it melted.
The residents of Blue Rapids, a small town located on Kansas Highway 9 in Marshall County, have decided this significant but largely unreported historical event deserves a monument. They plan to dedicate it today, in the town square, what may be one of the world’s only monuments to the ice ages of the world’s past. “We’re now world headquarters for monuments to the ice age,” joked Phil Osborne, a Blue Rapids resident.
During one of the last advances of the world’s past ice ages, according to the Kansas Geological Survey, giant glaciers changed the courses of our biggest rivers – and left thousands of heavy Sioux quartzite boulders and smaller stones behind when it all melted. That glacial period took place 400,000 to 500,000 years ago, said Rex Buchanan, interim director of the geological survey. Some geologists date the period further back, to about 600,000 years ago.
Osborne said one of his fellow Blue Rapids schoolmates, a paleontologist named George Callison, has worked hard to create the monument, which includes all-weather storyboards on concrete pillars telling how the glacial story unfolded. Callison, who Osborne said graduated from high school with him in 1958, also put up much of the money for the concrete pillars and the placement of the two pink boulders that decorate the display.
No public money was spent, Osborne said.
The last ice age ended about 10,000 years ago, Buchanan said, and though there was a glacier advance southward from the Arctic in that period too, the glaciers in that last ice age never got farther south than northern Iowa. The pink rocks so plentiful in northeast Kansas got dumped much earlier.
Tons of pink boulders and stones got ripped out of rock outcroppings in Minnesota – and were dragged inch by inch during thousands of years onto landscapes of northeast Kansas. They still can be found in cow pastures and along fence lines where farmers dating from the homestead era of the mid-1800s began prying them out of their fields, afraid the heavy stones would break their plowshares. The stones look unique, with an unusual pink sheen – and corners and edges rounded off, from having been rolled, smoothed and dragged all the way from Minnesota.
It is easy to see why the pink stones so obviously don’t belong here, Buchanan said. Most of Kansas’ geology is made up of yellow or white limestone, because Kansas was a sea bottom for millions of years. And yet in northeast Kansas we have limestone with a sprinkling of much denser pink boulders.
The glaciers were massive, Buchanan said, possibly 500 feet high in places in Kansas, and probably much thicker than that farther north. Only a small portion of Kansas ended up under ice, he said; the border would be in middle Washington County to the west, and then extending down in a curve so that the southern border would be roughly where the Kansas River now flows.
But some pink “glacial erratics,” as geologists call them, have been found south of that river, Buchanan said. The glacier from hundreds of thousands of years ago probably shaped the current courses of the Big Blue and the Kansas rivers, Buchanan said.
Blue Rapids residents plan an Ice Age Monument dedication at 11 a.m. today, at the Round Town Square, with Buchanan as a speaker and with a “woolly mammoth burger lunch” to follow in the town’s Community Center, Osborne said.
Besides the Ice Age Monument, Blue Rapids and surrounding Marshall County have a rich history. Town residents proudly tell visitors that Theodore Roosevelt once visited the town and gave a speech from the back of a train. The town once lured players from the New York baseball Giants and the Chicago White Sox to come play a game there.
Alcove Springs, a small and pretty parkland accessible to the public just north of town, was a camping spot for 19th-century pioneers in wagon trains using the Oregon Trail. The wagon ruts can still be seen in places just north of town.