At the request of the Massachusetts Department of Public Works, seismic and geologic studies were made for the projected Braintree-Weymouth By-Pass grade separation at Liberty Street in Braintree, Massachusetts. The work was performed in order to furnish data that would aid the engineers in preparing estimates of the quantity of bedrock to be excavated for this project. The study represents part of a cooperative program of the Massachusetts Department of Public Works and the United States Geological Survey. The work was performed in May 1949.