Bedrock geologic map of the Old Lyme quadrangle, New London and Middlesex Counties, Connecticut

Scientific Investigations Map 3052
Prepared in cooperation with the State of Connecticut, Department of Environmental Protection, Geological and Natural History Survey
By: , and 



The bedrock geology of the Old Lyme quadrangle consists of Neoproterozoic and Permian gneisses and granites of the Gander and Avalon terranes, Silurian metasedimentary rocks of the Merrimack terrane, and Silurian to Devonian metasedimentary rocks of uncertain origin. The Avalon terrane rocks crop out within the Selden Neck block, and the Gander terrane rocks crop out within the Lyme dome. The Silurian to Devonian rocks crop out between these two massifs. Previous mapping in the Old Lyme quadrangle includes the work by Lawrence Lundgren, Jr. Lundgren's work provides an excellent resource for rock descriptions and detailed modal analyses of rock units that will not be duplicated in this current report. New research that was not covered in detail by Lundgren is the focus of this report and includes (1) evaluation of the rocks in the core of the Lyme dome in an effort to subdivide units in this area; (2) structural analysis of foliations and folds in and around the Lyme dome; (3) geochronology of selected units within the Lyme dome; and (4) analysis of joints and the fracture properties of the rocks.

Study Area

Publication type Report
Publication Subtype USGS Numbered Series
Title Bedrock geologic map of the Old Lyme quadrangle, New London and Middlesex Counties, Connecticut
Series title Scientific Investigations Map
Series number 3052
DOI 10.3133/sim3052
Edition Version 1.0, Supersedes OFR 2006-1296
Year Published 2009
Language English
Publisher U.S. Geological Survey
Contributing office(s) U.S. Geological Survey
Description Report: iv, 25 p.; 2 Plates: 46 x 28 inches and 38 x 29.5 inches; Download Directory
Country United States
State Connecticut
County Middlesex County, New London County
Other Geospatial Old Lyme quadrangle
Projection Polyconic
Scale 24000
Online Only (Y/N) Y
Additional Online Files (Y/N) Y
Google Analytic Metrics Metrics page
Additional publication details