The depth to bedrock is perhaps one of the most important surfaces that is fundamental to many practical engineering, water resource, and geological problems. Yet it is not well understood everywhere. Knowing the depth to bedrock for transportation projects not only influences cost but may also affect selection of the appropriate foundation system for a particular structure. Furthermore, estimates of the bedrock depth, along with the type of overburden (e.g., glacial till, varved clay, sand and gravel) help determine the most appropriate subsurface investigation method to use during project planning, and reduces construction delays and claims brought forward by contractors. Accordingly, there is some level of uncertainty in planning subsurface investigations for any transportation project when depth to bedrock information is lacking.
This project provides interpolated statewide data layers of the depth to bedrock and bedrock altitude at 100-meter resolution based on currently available subsurface data. In addition, maps depicting the level of confidence in the estimate of the bedrock altitude and depth are also provided. The confidence is based on both the interpolated prediction standard error as well as the measurement uncertainties associated with the input data.
View or download the map data from MassGIS here
View a detailed report on the “Top of Rock” project here
Funding from MassDOT supported this work