Bedrock and Surficial Geology / Soils

Exposed bedrock on our site covered in vegetation

Bedrock Geology:

Our site is on the Duhnam Dolomite bedrock formation but lies close enough to its edge where some quartzite may be present. The formation is dolostone which is a carbonate sedimentary rock composed of mostly the mineral dolomite that is gray-pink in color. This formation formed in the Cambrian era which is the first geologic period of the Paleozoic era from 542 to 480 million years ago. Throughout the site there are rock formations that provide very good samples of the bedrock present throughout the site.

Surficial Geology:

 The site consists of primarily glacial till. This till could be seen while digging the soil pit which consisted of 40% till. The soil type is categorized as Farmington extremely rocky loam.    Multiple attempts at excavating soil pits led to the conclusion that the soil consisted of a shallow lair of a sandy loam and then a layer of sand before we ran into stones too large to dig around. The soil pit supported the soil type listed on the soil report. The abundance of rocks just below the surface of the soil was to be expected due to the site being located on the crest and side of a ridge where soils are always shallow.

Soils:

Here is our soil test dig site.

Dig Site - Hole

We dug to 30" below the surface...

Different colors of each layer dug up

...encountering two distinct soil layers along the way.

The first 3" was a dark, rich organic layer. Earthworms were found in this layer. Below that was a lighter sandy loam throughout to the floor of the dig.

pH testing of the soils

Here Amanda and Steve are testing the pH of the soil. The top organic layer was determined to be 7.9, while the sandy loam beneath was 7.1. A less acidic soil has more available nutrients for forest plants!

This is a piece of rock from our dig. The earth on our hectare plot is very rocky, which made digging through it a challenge.

Rock found on Site which easily
broke down into sand

Along the top edge, where the rock has been broken, a crystalline structure can be seen. The rock was easily fractured and scraped off into sand, which would explain the sandy loam of our soil. An application of hydrochloric acid on the exposed rock on our plot indicated presence of calcium carbonate. This may be how the pH of our soil is at a relatively high level.