In Massachusetts, the soil is usually made up of glacial and post glacial deposits over bedrock.
Framingham soil is typically made up of sand and gravel deposits left behind from retreating glaciers.
The glacial history of Framingham is easy to see because of the glacial landforms present in the town. Framingham had a lot of DRUMLINS, for instance.
Drumlins are oval or elongated hills composed of dense till believed to have been formed by the streamlined movement of glacial ice. The most famous drumlins in Massachusetts are Bunker Hill and Beacon Hill. The Harbor Islands in Boston Harbor are drumlins, as well. When I personally imagine a drumlin, I always picture World's End in Hingham, a Trustees of Reservations property where I spend a lot of time as a child. It turns out that World's End is one of the 30 islands of the Boston Harbor Islands National Recreational Area.
Framingham also has Kettle Holes, or Kettle Lakes, which are formed by chunks of ice left behind by glaciers that melt into lakes.
There are areas in Framingham that are not buildable because they are designated wetlands, or because they are under water, or because the slope of the hills is too steep (>15 degrees.) You also can't build on sites where there isn't enough soil over the bedrock to excavate for sewage systems or septic systems.