TRANSCENDENTAL GEOLOGY: HENRY DAVID THOREAU ON THE MOUNTAINS, ROCKS, AND WATERS OF NEW ENGLAND

Of all the Transcendentalist authors in mid-19th century New England, Henry David Thoreau (1817-1862) has arguably had the greatest effect on later American culture. Not only are several of his writings now recognized as literary classics, but his essays on natural phenomena have also led to his widespread recognition as a pioneer limnologist and ecologist. Although Thoreau's greatest contributions to modern science were in the field of botany, he also made many significant geological observations.

Thoreau spent the greater part of his life within walking distance of his birthplace in Concord, MA, and established his place in American literary history with a two-year sojourn on the shores of Walden Pond, a large glacial kettle pond near the southeastern border of the town. He accurately surveyed and sounded this “bottomless” pond in 1846. In sauntering and boating about Concord and the surrounding country, he described many geologic features, including the Fairhaven Cliffs, Brister's Spring, the “Deep Cut” with its “sand foliage,” and the limestone quarry and kiln in the swampy Estabrook Woods.

Though Concord was a constant source of inspiration, Thoreau also took many excursions throughout New England. Among those chronicled in his writings were a week-long boat trip on the Concord and Merrimack Rivers (culminating with an ascent of Mt. Washington) and later trips to Cape Cod, Mt. Wachusett, Mt. Greylock, Mt. Monadnock, the White Mountains, and the Maine Woods. His classic Cape Cod abounds in observations on beach processes and shoreline erosion. Mountains stimulated some of Thoreau's best geological work. He described what we now recognize as glacial striations and roches moutinees on Mt. Monadnock; noted the lithologic character of the rhyolite (“hornstone”) on Mt. Kineo; and elaborated on the physiography of Mts. Greylock, Kineo, Katahdin, and Washington.

Thoreau was well acquainted with the geological literature of his day, frequently referring to the reports of Edward Hitchcock and Charles T. Jackson. Though he early on read Charles Lyell's Principles of Geology and absorbed its uniformitarianism, he inexplicably ignored the ideas of Louis Agassiz on continental glaciation. Science was secondary—even somewhat suspect—to Thoreau. His greatest intellectual achievement was his recognition of the physical and spiritual relationships inherent in all natural phenomena.