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Formation

Tens of thousands of years ago, when the wooly mammoth still walked the earth, Michigan was a land of perpetual winter, covered, as it was, almost entirely in glaciers-great rivers of slow-moving ice.  As the glaciers moved down from the north, their tremendous weight and pressure dug up existing rocks, vegetable matter, and soil and ground it all together, moving it south into areas like Michigan.  Then, thousands of years later, the glaciers melted, leaving behind all of the matter they had moved south.  This matter became our soils, and, depending on the different materials the glaciers picked up, we get different types of soil.  That's why you can find over 450 different types of soil in Michigan today.

In the case of Kalkaska sand, the glaciers left behind bits of ground up sandstone and granite, along with some heavier particles known loosely as "loam".  Together, and in the right part of the state, these materials helped form ideal locations for certain types of plants to grow, including hemlock, oaks and some pines.  Such plants were crucial to the development of Kalkaska sand.

These plants took hold in the loose sands and thrived there, growing tall and leaving behind their dead leaves, needles, branches and eventually their trunks, too.  All this stuff-trunks, branches, needles and leaves-eventually fell to the forest floor and decayed there, forming the shallow layer of black topsoil found making up the top part, or horizon, of Kalkaska sand.  In addition to making up the top soil, many of the plants that grow on Kalkaska sand are very acidic, that is, their leaves and needles contain acids which drain into the soils when they decompose.  These acids create ideal conditions for certain types of microscopic (very tiny) life which is also important to the formation of Kalkaska sand.

Another important factor in the formation of Kalkaska sand is the amount of yearly snowfall it receives.  If you look at where Kalkaska sand is found in Michigan, you will see that it occurs in areas of very high snowfall.  An interesting thing about snow that not everybody knows is that it acts as a great insulator, similar to a winter coat.  Because of this, ground that receives high annual amounts of snowfall doesn't freeze as quickly as it would without the snow.  In some years, the ground doesn't freeze at all.  This means that the microscopic life forms living in Kalkaska sand can continue to do their thing year round.  It also means that water melting from the snow can continue to soak into the ground and drain or leach minerals from one layer of soil into another.  This is one of the reasons the layers of soil materials making up Kalkaska sand are so distinctive.  It's also the reason some of the layers appear to "drip" into lower layers.  Take a look at this picture to see an example.  The fact that this happens any single year is no big deal, but all those years together make up thousands of years of year-round leaching, which makes for some unique soil characteristics.