Mankato East Junior High eighth-graders spent their time in a different kind of classroom Wednesday.

The kind of classroom that features alluvial fans and glacial till, deleterious rock and prized Minnesota River Valley sandstone. The kind of classroom where shoes get muddy, hands get dirty, and field notes are scrawled haphazardly on a friend’s back.

That is, the kind of classroom that can’t be simulated in an actual classroom.

“You can’t re-create this,” said Lynell Senden, an earth science teacher at East Junior High as she sized up a broad face of uncut dolomite at the Southern Minnesota Construction quarry near Kasota.

“Because kids have been here and now they’ve seen it, it will make such an impact on their earth science experience.”

A month into the school year, Wednesday’s field trip for 210 East students marked the kickoff of their earth history unit.

But instead of reading in a textbook about how present-day Mankato was once buried at the bottom of an ocean, she took them to the Unimin mine near Ottawa to show them the white silica sand that is nearly identical in color and beauty to that found on Caribbean beaches.

And instead of giving a lecture on how glaciers deposited non-native rocks onto Minnesota soil millions of years ago, she had students sort rocks at the SMC quarry so they could see the wide variety of colors and textures.

“In a textbook, you just read,” said Amanda Broman. “But out here, you can interact with stuff.”

Students also had the opportunity to interact with the GPS units Senden procured through an Educare Foundation grant. Using GPS, students marked the elevations of each site they visited — Unimin, SMC, New Ulm Quartzite Quarry and Minneopa State Park — as well as the longitude and latitude.

Later on, Senden said students will use those coordinates on Google Earth to get a broader perspective on the geology of the Minnesota River valley.

“It’s very beneficial,” Senden said, “when students can see how rocks look and work. It gives them an idea of what happened in Minnesota history to form these rocks.”

Bryce Mortenson is already something of a rock expert. A rock collector himself whose prized stone is a sapphire he found while strolling the streets of St. Peter, Mortenson said he was looking particularly close to find a fossil.

And although he may not have had any luck, Mortenson said he enjoyed the chance to see the earth’s history up close.

“The most fun was seeing all the mining areas,” Mortenson said. “It’s definitely more fun out here.”