Garnets
Examine a handful of sand. You will find that it consists of light-colored particles (mostly Quartz) and of black particles. Under a microscope many of these dark particles look like little gems. They are actually a deep red and are true Garnets. Large Garnets are used as gem stones, small ones for sandpaper—further proof of the abrasive ability of windblown sand.
History in the Sand
In your handful of sand you may find particles that are neither Quartz nor Garnet. Minerals such as Feldspar, Biotite, Mica, Magnetite, Hornblende, and others can be identified by the geologist and are a clue to the original type of rock over which the glacier moved.
Beach Porcupines
These are hard-packed balls of twigs and grasses. Loose vegetable matter is very light and may be blown along by the wind for many miles. As it goes it adds other vegetation to itself, until packed into a very tight, hard ball. It may also get its start in the water by being whirled into a tiny ball; and later it is thrown onto the beach, to begin rolling along. A most curious souvenir!
MORE ABOUT THE DUNES
The face of the land is a storybook waiting to be read. The following books will help you piece together some of the story:
Henry Curtis Ahl, Dunes and Beaches of Essex County. Boston: Massachusetts Audubon Society, 1949. $.25 N. E. Chute and R. L. Nichols, Geology of the Coast of Northeastern Massachusetts. Massachusetts Department of Public Works and U. S. Geological Survey Cooperative Geologic Project, Bulletin #7. Boston, 1941. Out of print. Available in Museum of Science Library. John Henry Sears, The Physical Geography, Geology, Mineralogy and Paleontology of Essex County, Massachusetts. Salem, Mass.: Essex Institute, 1905. $6.00 Charles Wendell Townsend, Sand Dunes and Salt Marshes. Boston: L. C. Page, 1913. Out of print. Available in Museum of Science Library. ——, Beach Grass. Boston: Marshall Jones, 1923. $3.50