I walk, drive, run, jump and play on the earth all day every day, but how often do I look, really look, at the ground beneath my feet?

As a child, I learned the basics of geology. (Do you remember learning about sedimentary, igneous and metamorphic rock?) I learned about our planet’s core, and the formation of the continents, and maybe something about earthquakes and volcanoes. The teacher probably talked about how soil forms and how rivers change their paths over time, how lakes and even seas dry up. I learned about prehistoric times, when dinosaurs roamed the earth, and seas covered much of western Oklahoma and other parts of the U.S.

Natural forces have been at work wearing down the layers of rock beneath my feet. Wind buffets the rock, weathering it down into particles, scouring the surface and forming odd shapes. Likewise, water running over rock rubs surfaces smooth, creates pockets and even holes in solid rock. Ice (as glaciers) gouges deep grooves in solid rock, pushes boulders over land, and leaves rock-strewn valleys when the ice melts away.

In land not covered by mountains, the topography reflects the forces of nature that have been at work for ages since the original layers of bedrock were formed. Land may have been broken apart by earthquakes or pushed up by interior pressure to form mountains. Rolling hills and valleys tell a story, as do out-of-place boulders and strange protruding rock formations.
  
On top of the rocks that I live on is a layer of soil. Soil is formed when these geological layers (bedrock) are weathered away and break down into particles of mixed sizes: Clay (the smallest), silt (medium-sized) and sand (the largest). Between these particles are spaces filled with air, water and living organisms (insects, worms, bacteria and fungi). Soil may also include gravel and rock pieces that have not been completely broken down.

The geologic history of places means everything to what grows at that place on Planet Earth. Since topsoil comes from the erosion of the rocks below, the basic bedrock of an area will determine the color of the soil, and whether it is considered to be loamy or sandy or clay. As I travel, I notice soil colors. I also notice the rock formations that influence the topography of a place. Mountains, rolling hills, boulders, flatlands – all of these happen because of the rock folds – or lack thereof – in the earth beneath.

Travel to the Rocky Mountains, or the Appalachians, or even the ancient Wichita Mountains in Oklahoma, and it’s easy to talk about geology. Start a landscape project, and it doesn’t take long to discover what kind of rocks are already on the property, and what kind of rocks the designer thinks should be added to form just the right pathway or decorative element. Suddenly, I’m back in college geology again, remembering words I’d forgotten.

The same thing happens when building a home in a neighborhood away from a city’s water or sewer system. When considering digging a well for water, or putting in a septic tank for sewage, the experts want to know all about the type of rock in your area, and the soil that has formed from it.

It’s inescapable, but most of the time we don’t even notice soil. Yet it influences everything including the taste of the water we drink. (Water, after all, flows underground, over rocks and through soil to our water sources – whether they are rivers, lakes or groundwater wells.)

This week, as you look around, I challenge you to think about the geology of the place where you live. What is the geologic history? What forces of nature have been at work and affected your topography? What type of soil do you have in your yard, or in the park down the street? Are there nutrients (fertilizers) you must add to your soil so that grasses, flowers or vegetables can thrive?

I hope that this week’s Connection will encourage YOU to think a little more about the ground beneath YOUR feet.