Geotechnical Drilling Pine Castle What are the soil horizons?

Pine Castle geotechnical drilling clients are often curious about precisely what’s beneath their feet. In fact, most know relatively little about the geologic landscape that exists within such close proximity to our world.

The soil that sits beneath our feet is divided into a number of layers called “horizons.”  Each horizon is a distinct layer and it’s not uncommon to drill into most or all of these layers when performing geotechnical drilling. Pine Castle natives can read on to learn more about these different layers.

How do soil horizons effect geotechnical drilling?

Pine Castle geotechnical drilling projects can vary depending upon the soil composition and stone composition, among other factors. Regardless of the predominant soil type, the horizons are typically present in all locations.

So what are the soil layers or “horizons?”

O Horizon – Also called humus, this is the very top layer of earth, comprised of nutrient-rich organic debris that’s in the process of being turned into actual soil.

A Horizon – Also known as the topsoil layer, this horizon is where a majority of plant roots are situated; only a portion go deeper than this layer. A horizon is usually a blend of humus and particles of sand, minerals and silt.

E Horizon – Also called the eluviation layer (or “leaching layer”), this horizon is primarily comprised of sand and silt. Water tends to flow through this layer with ease since it contains little clay, few minerals and virtually no organic matter.

B Horizon – Also called subsoil, this layer is typically rich in mineral and clay deposits, which form as the water brings minerals down from the upper layers. This layer can contain fairly small chunks of stone and mineral, including iron, calcium carbonate and aluminum oxide. This is typically the deepest layer where you’ll find roots (and usually only for the very largest trees).

E Horizon – Also known as regolith, this layer is comprised of very rocky soil, with large stones broken off from the bedrock that sits below. Plant roots are never found in this layer and it contains very little organic material.

R Horizon – Also called bedrock, this layer is more or less solid rock. The composition of the bedrock does vary by location. In Florida and much of the south, the bedrock is comprised of limestone, which is quite soft.

If you’re seeking to learn more about the composition of the bedrock and other layers, you can invest in geotechnical drilling. Pine Castle natives often turn to drilling when evaluating the suitability of a site as a possible location for a structure or to investigate the possibility of sinkholes.