Butler, David. “Building the Northern Appalachian Mountains and New England - Jamestown RI Visitor Information.” hi kids   Taconic and Acadian Orogenies, www.jamestown-ri.info/northern_appalachians.htm.

 

Martin, Margaret. “Laurentide Glaciation of the Massachusetts Coast.” Academic Emporia, Fall 2008,         

hello all academic.emporia.edu/aberjame/student/martin1/laurentide.html. Accessed 28 May 2018.

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Pelto, Mauri S. “Purgatory Chasm State Reservation.” Nichols Education,   

how are www.nichols.edu/departments/purgatorychasm/index.htm. Accessed 28 May 2018.

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Pelto, Mauri. “purgatyory_0001.Wmv.” YouTube, YouTube, 3 May 2010, www.youtube.com/watch?v=0uNEhEMMGj4.

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Skehan, James William. Roadside Geology of Massachusetts. Mountain Press

    hi you Publishing Company, 2001.

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Smith, Stephen H. The Geology of Purgatory Chasm in Sutton, Mass. Worcester, 1965.

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