National Park Service U.S. Department of the Interior Natural Resource Program Center Acadia National Park Geologic Resources Inventory Report Natural Resource Report NPS/NRPC/GRD/NRR—2010/232 THIS PAGE: Visitors navigate along the beautiful Acadia coast. National Park Service photograph by Cynthia Ocel. ON THE COVER: Hiking to the tops of summits offers views of ocean and fall colors. Gor- ham Mtn Trail. National Park Service photograph by Ginny Reams. Acadia National Park Geologic Resources Inventory Report Natural Resource Report NPS/NRPC/GRD/NRR—2010/232 Geologic Resources Division Natural Resource Program Center P.O. Box 25287 Denver, Colorado 80225 August 2010 U.S. Department of the Interior National Park Service Natural Resource Program Center Ft. Collins, Colorado The National Park Service, Natural Resource Program Center publishes a range of reports that address natural resource topics of interest and applicability to a broad audience in the National Park Service and others in natural resource management, including scientists, conservation and environmental constituencies, and the public. The Natural Resource Report Series is used to disseminate high-priority, current natural resource management information with managerial application. The series targets a general, diverse audience, and may contain NPS policy considerations or address sensitive issues of management applicability. All manuscripts in the series receive the appropriate level of peer review to ensure that the information is scientifically credible, technically accurate, appropriately written for the intended audience, and designed and published in a professional manner. This report received informal peer review by subject-matter experts who were not directly involved in the collection, analysis, or reporting of the data. Views, statements, findings, conclusions, recommendations, and data in this report do not necessarily reflect views and policies of the National Park Service, U.S. Department of the Interior. Mention of trade names or commercial products does not constitute endorsement or recommendation for use by the U. S. Government. Printed copies of this report are produced in a limited quantity and they are only available as long as the supply lasts. This report is available from the Geologic Resources Inventory website (http://www.nature.nps.gov/geology/inventory/gre_publications.cfm) and the Natural Resource Publications Management website (http://www.nature.nps.gov/publications/ NRPM). Please cite this publication as: Graham, J. 2010. Acadia National Park: geologic resources inventory report. Natural Resource Report NPS/NRPC/GRD/NRR—2010/232. National Park Service, Ft. Collins, Colorado. NPS 123/105335, August 2010 ii NPS Geologic Resources Division Contents Lists of Figures and Tables ........................................................................................... iv Executive Summary ....................................................................................................... v Acknowledgements ...................................................................................................... vi Credits ........................................................................................................................................................................ vi Introduction ................................................................................................................... 1 Purpose of the Geologic Resources Inventory ............................................................................................................... 1 Regional Information ................................................................................................................................................... 1 Geologic Setting .......................................................................................................................................................... 2 Cultural History ............................................................................................................................................................ 4 Geologic Issues ............................................................................................................ 11 Mass Wasting and Slope Failure ................................................................................................................................. 11 Coastal Erosion .......................................................................................................................................................... 11 Sustainability of Sand Beach ....................................................................................................................................... 12 Seismic Activity .......................................................................................................................................................... 12 Global Climate Change .............................................................................................................................................. 13 Visitor Impact to Natural Resources ............................................................................................................................ 14 Other Potential Issues ................................................................................................................................................. 14 Geologic Features and Processes ................................................................................ 23 Bedrock Features ....................................................................................................................................................... 23 Glacial Features .......................................................................................................................................................... 27 Coastal Features ......................................................................................................................................................... 29 Map Unit Properties .................................................................................................... 39 Geologic History .......................................................................................................... 43 Paleozoic Era (542 to 251 million years ago) ............................................................................................................... 43 Mesozoic Era (251 to 65.5 million years ago) .............................................................................................................. 44 Cenozoic Era (the past 65.5 million years) ................................................................................................................... 44 Glossary ........................................................................................................................ 52 Literature Cited ............................................................................................................ 56 Additional References ................................................................................................. 60 Appendix A: Overview of Digital Geologic Data ....................................................... 61 Appendix B: Scoping Session Participants ................................................................. 63 Attachment 1: Geologic Resources Inventory Products CD ACAD Geologic Resources Inventory Report iii List of Figures Figure 1. National Park Service location map for Acadia National Park, Maine ................................................................... 5 Figure 2. Detail maps of Acadia National Park: Mount Desert Island, Isla au Haut, and the Schoodic Peninsula .................. 6 Figure 3. Legislated Acadia National Park boundaries and conservation easements as of April 2010 .................................. 7 Figure 4. Blocks of granite form the rocky coastline at Bass Harbor Head .......................................................................... 8 Figure 5. Bedrock and surficial geologic units in Acadia National Park ............................................................................... 9 Figure 6. Stone bridge along a carriage road, Mount Desert Island ................................................................................. 10 Figure 7. Slumping above the path to Thunder Hole ....................................................................................................... 16 Figure 8. Slope failure and slumping along Hunters Brook, Mount Desert Island ............................................................. 17 Figure 9. Examples of mass wasting on Mount Desert Island caused by the October 2006 earthquake ............................ 18 Figure 10. Waves from Hurricane Bill come ashore at Mount Desert Island, August 23, 2009 ......................................... 19 Figure 11. Winter seas hammer the coastline of Acadia National Park ............................................................................ 20 Figure 12. Aerial view of Sand Beach, Mount Desert Island ............................................................................................ 20 Figure 13. Erosion and deposition of Sand Beach ........................................................................................................... 21 Figure 14. Erosion of the dune ridge. ............................................................................................................................. 21