Bibliography

1. Pelto, Mauri S. "Purgatory Chasm State Reservation." Nichols College. Nichols College, n.d. Web. 22 May 2013. .

2. "Purgatory Chasm State Reservation." Mass.gov. Department of Conservation and Recreation, n.d. Web. 22 May 2013. .

3. "Laurentide Ice Sheet." Britannica. Ed. David Gelernter. Encyclopedia Britannica, n.d. Web. 22 May 2013. .

4. "Stop #1 - Purgatory Chasm." Planetary Geosciences Group. Brown University, n.d. Web. 22 May 2013. .

5. Richardson, Allison. "Weathering and Soil Formation." Mrs. Richardson's Earth Science Class Information. LIncoln-Sudbury Regional High School, n.d. Web. 26 May 2013. .

6. Waggoner, Ben M., and Brian R. Speer. "The Proterozoic Eon." Ed. Sarah Rieboldt and Dave Smith. University of California Museum of Paleontology . U of California Museum of Paleontology, n.d. Web. 28 May 2013. .

7. Osborne, Cassie. "Purgatory Chasm State Reservation, MA." Cassie’s Site. Cassie Osborne, n.d. Web. 28 May 2013. .

8. Rodgers, John. "Scituate Granite Gneiss." USGS Science for a Changing World. USGS, n.d. Web. 29 May 2013. .

9. Martin, Margaret. "Laurentide Glaciation of the Massachusetts Coast." Laurentide Glaciation of the Massachusetts Coast. Margaret Martin, n.d. Web. 29 May 2013. .

10. Collins, Allen G. "Geologic Time Scale." Ed. Robert Guralnick et al. University of California Museum of Paleontology. University of California Museum of Paleontology, n.d. Web. 29 May 2013. .

11. Mikolajczyk, Jennifer. "Interstate Park." U of Wisconsin Eau Claire. U of Wisconsin, n.d. Web. 29 May 2013. .

12. Martin, Margaret. "LAURENTIDE GLACIATION OF THE MASSACHUSETTS COAST." Laurentide Glaciation of the Massachusetts Coast. Emporia State University, n.d. Web. 30 May 2013..

Image Citations

1. "Colorado Geological Survey Time Chart." Chart. Colorado Geological Survey. Colorado Department of Natural Resources, n.d. Web. 29 May 2013. .

2. Axelsson. Rock302. N.d. Photograph. Scandinavian Mineral Gallery. Axelsson.

3. "Feldspar Cleavages." Department of Geology and Planetary Science. U of Pittsburgh, n.d. Web. 29 May 2013. .

4. Harper, Stephen B. "M17." ECU. East Carolina University, n.d. Web. 29 May 2013. .

5. "Purgatory Chasm USGS Midford Quad." Map. Topozone. Trails.com, n.d. Web. 29 May 2013. .

6.Image of Glacier. Digital image. USGS. US Geological Survey, n.d. Web. 30 May 2013. .

All other images were taken by Aaron Epstein, Seth Joachim and Sam Neil.