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Stearns County. By: Grace Larson. Stearns County was founded in 1855 and was named after Charles Thomas Stearns, a local politician. .

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Stearns county

Stearns County

By: Grace Larson

Stearns county

Stearns County was founded in 1855 and was named after Charles Thomas Stearns, a local politician.

The East border of Stearns County is the Mississippi River. The land consists of rolling hills, scenic lakes, and woodlands of a mixture of coniferous and deciduous trees. There are 166 lakes in the county of Stearns.

From Wikipedia, the free encyclopedia



*Stratified sediment washed out from a glacier by melt water streams and deposited in front of the end moraine.

*Sand, gravelly sand, and cobbly gravel.

Peat and muck

Peat and Muck

  • Partially decomposed plant matter deposited in marshes.

    • Includes fine-grained organic matter, marl, narrow deposits of alluvium along streams, narrow beach deposits, and small bodies of open water.

  • In developed areas, many of these deposits have been buried under artificial fill. The organic sediment is commonly removed prior to filling in areas where major structures are built.

Floodplain alluvium

Floodplain Alluvium

  • Mississippi River alluvium consists of generally less than six feet of silt, loam-to-loamy sand, overlying sand, gravelly sand, or cobblygravel; also some scattered wood and shell fragments.

  • Some depressions have been filled with thick silty to clay like sediment.

Undifferentiated paleoproterozoic and achaean rocks

Undifferentiated Paleoproterozoic and Achaean Rocks

  • Bedrock at or near the land surface; consists of intrusive, gneissic, and schistose rocks of Paleoproterozoic and Late Achaean ages.

*The large block of banded Morton Gneiss is about 3-3.5 billion years old.

*The folded, metamorphosed, banded iron formation is from the Atlantic City mine in Wyoming.

*The Stromatolitic iron-formation is made of fossil algae, from the Mary Ellen Mine on the Mesabi Range, a Biwabik Iron-formation. It is 1.85 billion years old.

Granite history

Granite History

  • Over a billion years ago, molten rock beneath Stearns County surged toward the earth’s crust. As the rock cooled, the minerals in the rock condensed and hardened, forming deposits of very durable granite.

  • Outcroppings of these Pre-Cambrian rocks are found in a 10 square mile area mainly between cnesbau-export and Rockville. Colored granite deposits were discovered here in 2007, which gave the city it’s nickname of "The Granite City." These porphyritic igneous rocks are a true granite of Early Proterozoic age (1700-1800 million years ago).


Granite history cont d

Granite History Cont’d.

  • The main minerals evident in the rock are quartz, potassium feldspar, plagioclase feldspar, and biolite. Smaller amounts of zircon, apatite, hornblende, chlorite sericite and sphene also occur. The potassium feldspars are the large crystals, (phenocrysts), set in an otherwise equi-granular matrix. The pink color of diamond pink is due to pink coloration in those particular rocks’ feldspars.

Stearns county

Statue in front of St. Cloud Technical College Plaza

Made of granite, stainless steel and cedar.



St. Cloud Quarry

St. Cloud Red Granite

Rainbow Quarry



*Slate forms when shale, which consists of clay minerals, is put under pressure with temperatures of a few hundred degrees or so. Then the clays begin to revert to the mica minerals from which they formed.

*Slate is usually dark, but it can be colorful too. High-quality slate is an excellent paving stone as well as the material of long-lasting slate roof tiles. Slate also makes the best billiard tables.

*Blackboards and handheld writing tablets were once made of slate, and the name of the rock has become the name of the tablets themselves.

*With further metamorphism, slate turns to phyllite, then schist or gneiss.



Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains. Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any color, but the most common colors are tan, brown, yellow, red, gray and white.

From Wikipedia, the free encyclopedia



Stearns County, MN

Gypsum is a mineral made up of calcium sulphate hydrate. Gypsum is mined in opencast quarries or underground galleries, using specific drilling equipment and nonpolluting explosives. Crushed and heated in kilns, the gypsum is finally ground to obtain plaster powder.



This unique outcrop shape is the result of erosion of weathered bedrock.

Glaciation merden lake esker

Glaciation*Merden Lake Esker*

  • A gravel pit in south central Stearns County, Minnesota, exposes sand and gravel of the Merden Lake esker which is thought to have been deposited by a sub glacial stream associated with the Wisconsinan-aged Superior Lobe of the Laurentide ice sheet.

  • The presence of eskers indicates free melt water drainage toward the glacier margin, and deposition occurs as flow velocities are falling. The Merden Lake esker is a 1.5 km long, sinuous ridge that begins in the very SW 1/4 of Section 19, T124N, R29W and spans southwest through the NW 1/4 of Section 30, T124N, R29W and ends in the NE 1/4 of Section 25, T124N, R30W, Avon, Minnesota (Stearns County, Minnesota) .


Stearns county

Maps showing the location of the Merden Lake esker in Stearns County, Minnesota. The county map (top right) shows general glaciation. The topographic map (bottom) shows relief of the esker and the cross-sectioned region that was used for excavation.


Stearns county

Photograph of the esker as viewed from the southwest. A-B corresponds to the label on the topographic map in the previous slide.

The trench marker corresponds to a trench depth of ~5 m. For scale, author Aaron Hirsch is standing on a graveled slope midway up the esker face.

Aaron Hirsch

Champion dam sartell mn

Champion Dam-Sartell, MN

  • The Champion Dam played a role in the major flood of 1965. Ice dams formed in a number of unexpected places that year, causing large pools of water to form. Once the ice dam formed behind the Champion Dam, rising as high as 24 feet above the normal water level, the ice dam hit the ice breakers that are part of the dam structure, and the ice dam let go. A wall of water flowed down the Mississippi river, overtopping the Saint Cloud dam. The surge of water eventually flooded parts of Coon Rapids, and contributed to the already serious flooding in the Twin Cities area.

Stearns county

Champion Dam

Sedimentary layers

Sedimentary Layers



Quarry Four in St. Cloud, also known as “Oberg”, has one of the best preserved faults within the park.

This is a moderate sized quarry with a maximum depth of 57 feet located in the north, where the wall under water is steep. Part of the wall is exposed above water, and part below; the south wall is higher and more steep than on the north.

Faults cont d

Quarry Ten is one of the smallest and more shallow quarries in the park. It has a maximum depth of 20 feet and has a low, swampy area along the eastside.

Faults Cont’d.

The southwest part of this quarry is continuous with an outcrop that exposes a contact zone between red and gray granite. The outcrop has many mini-faults which may be related to a larger fault.

Quarry ten displays good glacial polish. Most of the walls of the quarry consist of glacial overburden.

Basalt dike

Basalt Dike

*Red granite is the dominant rock type in Quarry Three. The most important geologic feature is a wide dike of fine-grained, black basalt located along the west high wall. This is the only basalt dike oriented northwest-southeast in the park and probably one of only a few in central Minnesota.

*There are mini-faults at the north end, in the middle of the east side, and in the southeast corner. These faults probably controlled the formation of the northwest dike.

Basalt dike cont d

Basalt Dike Cont’d

*Excellent glacial polish is found on outcrops at the top of the south wall.

*Quarry Three is one of the shallower quarries in the park with a maximum depth of 25 feet. Most of the high walls are bedrock.



  • On October 26, 1996, fourteen tornadoes touched down in Central and West Central Minnesota.

  • Three tornadoes touched down in Stearns County

  • An F1 hit 6 miles South West of Belgrade to Brooten, also touching down in Kandiyohi county.

  • Another F1 touched down 3 miles West of Clearwater to 2 miles North West of Clearwater .

  • Minutes later, the third tornado, an F2, touched down 5 miles South, South West of Albany to 2 miles West of Albany.

  • There were no fatalities throughout the entire state.

Stearns county

Tornadoes forming over Stearns County



  • Google

  • Hirsch, Aaron C., et. Al. “Analysis of the Merden Lake Esker, Stearns County, Minnesota: A New Interpretation.” American Journal of Undergraduate Research. 3 Vols. College of St. Benedict/ St. John’s University: Collegeville MN, 2004. 3 Vols. 1-3.

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