THE FIRST CENTURY OF GLACIAL GEOLOGY INVESTIGATIONS IN THE WHITE MOUNTAINS, NEW HAMPSHIRE: 1840-1940

The study of glaciation in the White Mountains commenced during the mid 1800s. Glacial “drift” sediments and erosional features were examined by State Geologist Charles Jackson in 1841 and the famous British geologist Sir Charles Lyell in 1845, who attributed them to the action of marine waters and icebergs. Louis Agassiz first visited the area in 1847 and saw evidence of widespread glaciation. Agassiz and other workers in the mid to late 1800s claimed the White Mountains were overridden by an ice sheet followed by local glaciers radiating from the high peaks. George Vose published the first striation map of the area in 1868. Charles Hitchcock’s 1870s geological survey of NH added much information on glacial deposits, including an atlas with hand-colored surficial geologic maps of the state. Hitchcock also showed that ice had overridden the top of Mt. Washington. Moraine ridges in the Bethlehem area and associated glacial-lake deposits in the upper Ammonoosuc River valley became the focus of debate concerning the source and behavior of glacial ice in the White Mountains. In 1870 Agassiz claimed that late-glacial alpine ice flowed north from the Franconia Range and deposited the moraines. Warren Upham collectively named them the Bethlehem Moraine in 1904 and agreed they were built by a local glacier. However, deposition of White Mountain moraines “by the Laurentian ice sheet” was recognized by Hitchcock in 1897, and James Goldthwait’s 1916 paper proved that the Bethlehem Moraine was formed by continental ice. Goldthwait also described glacial cirques in the Presidential Range and evidence that they predate the last ice sheet. Ernst Antevs published the first varve chronology for glacial Lake Hitchcock in 1922; his work and Richard Lougee’s 1935 paper used varve sections west of Littleton to constrain the duration of the glacial readvance that built the Bethlehem Moraine. Lougee also defined and named many of the ice-dammed glacial lake stages in the northwestern White Mountains. The first century of research concluded in the 1930s with Richard Flint’s hotly contested argument that the most recent (Laurentide) ice sheet disappeared by stagnation and downwastage, without active-ice retreat or deposition of moraines. This paradigm shift was dominant for 50 years but has been refuted by recent studies of White Mountain glaciation.