This USGS Bulletin Report describes the buried bedrock valley between Wilmington and the Charles River in Massachusetts. It is an important historical work that establishes the extent of the buried bedrock valley in the northwestern part of the state and describes the sediments that have filled it in since the last glaciation. It lays out the profile of the buried valley, discusses how the sediments were deposited over time, and describes the different lithologies present. A surficial geology map accompanies the article.
Full text and geologic map available free from the USGS.