Prototype three-dimensional surficial materials map of the Marlborough quadrangle, Massachusetts

This map integrates well-drilling data with surficial geologic mapping and bedrock geology to produce a true three-dimensional model of the subsurface conditions within the Marlborough quadrangle, Massachusetts. The first component of this model is a map depicting a three-dimensional block diagram of the stratigraphic units that overlie the bedrock surface. The map also presents three-dimensional depictions of the individual stratigraphic units, their aerial extent and volumes.

In addition to the map, the supporting grid files, database and documentation for the three-dimensional model are provided.

This three-dimensional model of the subsurface stratigraphy of the Marlborough quadrangle provides a tool to visualize and explore the relationships of the subsurface units to one another, to the underlying bedrock, and to the water bearing fractures within the bedrock.

There are three immediate benefits of this three-dimensional model:

1. it provides a better estimate of the volume of sand and gravel resources, surpassing current assessments it affords an estimate of the volume of water available in storage, making it a more complete measure of our water assets.
2. it includes grid files of each stratigraphic unit, which provides a better initial conceptual model of the aquifer systems. The consulting community and water managers can import these grid files into groundwater modeling software for numerical analysis. In addition, the three-dimensional model can better delineate ground water flows, areas of groundwater recharge, and aquifer interconnectedness.
3. It will also help identify possible contaminant pathways and assist in the placement of ground water monitoring wells. The model can also be used to assist with the planning of major construction projects, assess the impacts from development, provide guidance for land use planning and smart growth initiatives. In total, a three-dimensional model of the subsurface provides critical geologic information for natural resource decision making.