History of Research on Glaciation in the White Mountains, New Hampshire (U.S.A.)
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Géographie physique et Quaternaire, 1999, vol. 53, n° 1, p. 7-24, 6 fig. HISTORY OF RESEARCH ON GLACIATION IN THE WHITE MOUNTAINS, NEW HAMPSHIRE (U.S.A.) Woodrow B. THOMPSON*, Maine Geological Survey, 22 State House Station, Augusta, Maine 04333-0022 U.S.A. ABSTRACT, 1999, vol. 53, n° 1, 6 fig., 53(1), 1999W. B. THOMPSON The glacial geology of the RÉSUMÉ Histoire de la recherche sur les ZUSAMMENFASSUNG Geschichte der For- White Mountains in New Hampshire has been glaciations dans les White Mountains du New schung über die Vergletscherungen in den Whi- the subject of many investigations since the Hampshire (É.-U.A.). La géologie glaciaire des te Mountains, New Hampshire. Die glaziale 1840’s. A series of controversies evolved dur- White Mountains au New Hampshire a fait l’ob- Geologie der White Mountains in New ing this period. First was the question of what jet de nombreuses études de 1840 à 1940. Les Hampshire ist seit 1840 Thema vieler Studien geologic processes were responsible for erod- recherches ont donné lieu à différentes con- gewesen. In dieser Zeit entstand eine Reihe ing the bedrock and depositing the cover of troverses au cours de cette période. Il y a von Kontroversen. Die erste Frage war, welche surficial sediments. By the 1860’s, the concept d’abord eu la question des processus géolo- geologischen Prozesse für die Erosion des an- of glaciation replaced earlier theories invoking giques responsables de l’érosion du substra- stehenden Gesteins und die Ablagerung der floods and icebergs. Research in the late tum et de la mise en place des sédiments de Decke von Oberflächensedimenten verant- 1800’s concerned the relative impact of conti- surface. Vers les années 1860, l’hypothèse wortlich waren. In den 60er Jahren des letzten nental versus local glaciation. Some workers des glaciers a prévalu sur les théories évo- Jahrhunderts ersetzte das Konzept einer Ver- believed that surficial deposits in northern New quant les inondations et les icebergs. La re- gletscherung frühere Theorien, die Über- Hampshire were the product of valley glaciers cherche à la fin du XIXe siècle cherchait à schwemmungen und Eisberge ins Feld führten. radiating from the White Mountains, but in the déterminer l’apport relatif des glaciations con- Die Forschung im späten 19. Jahrhundert be- early 1900’s continental glaciation was estab- tinentales et des glaciations locales. Certains schäftigte sich mit der relativen Auswirkung der lished as the most important process across chercheurs croyaient que les dépôts de surfa- kontinentalen im Verhältnis zur lokalen Verglet- the region. Debate over the extent and timing ce dans le nord du New Hampshire prove- scherung. Einige Forscher glaubten, dass of alpine glaciation in the Presidential Range naient de glaciers alpins issus des White Oberflächenablagerungen in Nord-New has continued until recent years. The most in- Mountains, mais au début du XXe siècle le con- Hampshire das Produkt von Talgletschern wa- tensely argued topic has been the manner in cept de la glaciation à l’échelle continentale a ren, die von den White Mountains ausgingen, which the Late Wisconsinan ice sheet with- été établie comme étant le processus principal aber zu Beginn des 20. Jahrhunderts bestimm- drew from the White Mountains: whether by dans la région. Toutefois, le débat sur l’exten- te man die kontinentale Vergletscherung als rapid stagnation and downwastage, or by pro- sion et le déroulement des glaciations alpines den wichtigsten Prozess in der ganzen Region. gressive retreat of a still-active ice margin. The dans le Presidential Range s’est poursuivi jus- Die Debatte über die Ausdehnung und den zeit- stagnation model became popular in the qu’à récemment. La question la plus discutée lichen Ablauf der alpinen Vergletscherung in 1930’s and was unchallenged until the late concerne la façon dont s’est fait le retrait de l’in- der Presidential Range hat bis vor kurzem fort- 1900’s. Following a research hiatus lasting landsis wisconsinien : stagnation et ablation gedauert. Am intensivsten hat man darüber ge- over 40 years, renewed interest in the glacial rapides du front ou retrait progressif d’une mar- stritten, wie die Spät-Wisconsin-Eisdecke sich history of the White Mountains continues to in- ge glaciaire encore active. Le modèle de la sta- von den White Mountains zurückgezogen hat : spire additional work. gnation l’a emporté dans les années 1930 et entweder durch schnelles Stagnieren und Ab- est demeuré incontesté jusqu’à la fin du XXe wärtszehrung oder durch progressiven Rück- siècle Après une interruption de plus de qua- zug eines immer noch aktiven Eisrands. Das rante ans, un intérêt renouvelé a inspiré des Stagnier-Modell wurde in den 30er Jahren un- travaux additionnels sur la question. seres Jahrhunderts populär und blieb bis gegen Ende des 20. Jahrhunderts unumstritten. Nach einer über 40 Jahre dauernden Unterbrechung der Forschungen beginnt ein neues Interesse an der glazialen Geschichte der White Moun- tains wieder zusätzliche Forschungen einzuleiten. Manuscrit reçu le 22 mai 1998 ; manuscrit révisé accepté le 11 décembre 1998 * E-mail address: [email protected] 8 W. B. THOMPSON INTRODUCTION combination of these types of glaciers? The other problem was to understand the style of deglaciation, which has been New Hampshire’s White Mountains (Fig. 1) have attracted a persisent research theme in the White Mountains. Strati- scientists since the early 1800’s. The first geologists and bot- graphic exposures recording pre-Late Wisconsinan glacial anists who worked in the region were explorers as well as cycles are rare in northern New Hampshire, so much atten- researchers. Their pioneering work through the mid to late tion has focused on the evidence of Late Wisconsinan ice 1800’s was intertwined with the economic development of recession. Arguments surrounded the question of whether the White Mountains and the growth of a major tourism there was a distinct northward-retreating ice margin, which industry. Fundamental concepts and problems in New presumably was associated with active glacial flow, as England glacial geology were tested here as researchers opposed to rapid stagnation of the entire ice sheet due to built upon knowledge accumulated by previous generations. thinning and separation over the mountainous terrain. This paper reviews the evolution of glacial studies and controversies in the White Mountains. The time period cov- The deglaciation controversy peaked in the 1930’s, fol- ered here spans slightly more than 150 years. It begins with lowed by a period of inactivity extending nearly four decades. introduction of the glacial theory in the 1840’s and extends to It seemed that the stagnationists had won the debate, and recent and ongoing investigations of the 1990’s. The author glacial geologists looked to other parts of the world for new has concentrated mainly on the first century of research problems. However, interest in the White Mountains has (1840-1940). This was an important period when glacial the- experienced a resurgence during the last 20 years. Student ories and field methods were developed in the White Moun- theses and detailed investigations of glacial deposits by tains, and for which a synthesis has not been previously workers from academic institutions and government agen- published. cies have shown that much remains to be learned about this familiar part of New England. Another recent development Early geologic work in the White Mountains addressed has been the completion of large-scale (1:25000 metric the question of whether glaciers formerly existed in this part series) topographic mapping by the U. S. Geological Survey. of the world. Following the acceptance of glaciation, two con- Unfortunately, these maps often show the terrain with less troversies dominated glacial studies from the late 1800’s until detail and accuracy than the older 1:62,500 quadrangles. 1940. First was the issue of determining the origin and mag- nitude of glaciation. Was the area affected mainly by alpine The geologists who worked in the White Mountains have glaciers, a local ice cap, a continental ice sheet, or some often been as interesting as the theories they advocated. FIGURE 1. 1:500,000-scale map of the White Mountain region, Carte à 1/500 000 de la région des White Mountains, montrant les showing principal towns and rivers mentioned in the text. principales villes et rivières mentionnées dans le texte. Géographie physique et Quaternaire, 53(1), 1999 HISTORY OF RESEARCH ON GLACIATION IN THE WHITE MOUNTAINS 9 Detailed characterization of these scientists is beyond the stayed at T. J. Crawford’s Notch House, which was one of the scope of this paper, but the biographic references cited here earliest hostelries in the White Mountains. In 1840 he and provide further details about them. The reference section the mountain guide Abel Crawford made the first horseback also includes a comprehensive list of publications on glacial ascent of Mount Washington (the highest mountain in New studies in the White Mountains, which is intended to be use- Hampshire, with a summit elevation of 1917 m). ful to both geologists and historians. Unfortunately, the Jackson and his contemporaries referred to surficial sedi- research for this paper has uncovered few photographs or ments as “diluvium” or “drift”. He adhered to a theory that field notes documenting the day-to-day activities of early was popular at the time, that these sediments were depos- geologists in the White Mountains. The author has assem- ited by a marine flood carrying icebergs. Strong ocean cur- bled a gallery of their portraits (Fig. 2), but candid photo- rents were assumed to have dragged rocks across ledges, graphs taken in the field are scarce. This lack of original producing grooves on their surfaces. Although he never con- source materials has made it difficult to reconstruct what cluded that New Hampshire had been glaciated, Jackson at was actually seen at controversial localities mentioned in least made significant observations on what were later published literature.