The Ice Age Trail in Maine: An Experience for Geo/Eco-travelers

This project will design and produce 200,000 copies of an Ice Age Trail map that interprets for informal learners (tourist travelers, local residents, school students) the late Quaternary history of eastern coastal Maine, glaciated North America and the north Atlantic region. The map will lead geo/eco-travelers along public roads to critical stops where they can observe glacial, glaciomarine and vegetation features, as well as historical and human events described and interpreted on the map in photos, diagrams and text. The travelers will be drawn from the approximately 4 million visitors to Maine\u27s coastal state and national parks. Additional dissemination will be via web cast through at least five separate websites. Maine Ice Age Map and Guide: Down Eas

Collaborative Research: West Antarctic Ice Sheet Stability: The Glacial Geologic Record from the Ohio Range of the Horlick Mountains in the Bottleneck

This award supports a project to document former high stands and assess the stability of the West Antarctic ice sheet (WAIS) at the Ohio Range near the head of Mercer Ice Stream (formerly Ice Stream A). The field location is situated in the Bottleneck , a unique, relatively narrow passage in the Transantarctic Mountains connecting the West and East Antarctic ice sheets. The location lies near the ice divide and is thus well situated to determine past interior ice elevation. The research will involve geologic mapping of glacial deposits and erosion features combined with cosmogenic surface exposure dating on the Ohio Range nunataks to determine the chronology of past higher ice sheet levels and local glacier fluctuations. Exposure ages of fresh glacial erratics, up to 60 m above the present ice level will be used to constrain the timing of the last high stand and subsequent draw down of the WAIS in this sector. Exposure ages of debris bands on the ice sheet surface will constrain the duration of continuous ice cover near the present elevation. A complimentary local proxy climate record will also be obtained from a chronology of the local glacier moraines. Data obtained from the proposed research will contribute to the development of time-dependent, non-equilibrium models of the WAIS, at and since the last glacial maximum 20,000 years ago, a major objective of the West Antarctic Ice Sheet Initiative. Age control on ice sheet elevation from this key location, near the head of the Mercer Ice Stream, will complete chronologic coverage extending from the ice age terminus in the Ross Sea, through McMurdo Sound and the southern Transantarctic Mountains, to the onset area near the ice divide. In addition, the glacial geologic record in the Bottleneck will reflect the history of the interaction of WAIS and EAIS, which could be used to test hypotheses of Pleistocene collapse of the WAIS. The future behavior of the WAIS is of significant interest to society because of its linkage to sea level. Melting of Antarctic ice sheets would raise sea levels, negatively impacting the large portion of the human population living near the world\u27s coasts. The research is designed to provide necessary data on the past history of the WAIS to the ice sheet modeling community in order to accurately predict the future behavior of the ice sheet. In addition, the proposed research incorporates both graduate and undergraduate student education and involves them in research with goals that are of societal significance

Reconnaissance surficial geology of the Mount Desert [15-minute] quadrangle, Maine

Maine Geological Survey, Open-File Map 74-7https://digitalmaine.com/mgs_maps/1517/thumbnail.jp

SGER: Is Bolling Warming Recorded by the Southeastern Margin of the Laurentide Ice Sheet?

This award, under the auspices of the Small Grants for Exploratory Research (SGER) program, uses funds to increase the chronologic control for the southeastern margin of the Laurentide Ice Sheet (LIS). Ultimately, the researchers want to explore whether they are able to document the response of the ice sheet to major shifts in atmospheric temperature and assess the ability of the ice sheet to produce large volumes of meltwater.The effect of prominent climate events, such as the Bolling warming (13,000 radiocarbon years before present), on the dynamics of the Laurentide Ice Sheet (LIS) remains unknown and yet has important implications for understanding the impact of climate change via glacial meltwater pulses and sea-level changes. The researchers suspect that the abrupt change in style of deglaciation corresponds to the onset of Bolling warmth, but they argue that the current chronology is not sufficient to determine if that is, in fact, the case. Specifically, the researchers want to collect and date fifty (50) new samples of shells and marine algae associated with the coastal moraine belt and the Pineo Ridge End Moraine Complex (PRC). These dates will help bring their chronology of the region up to modern standards and allow them to determine whether or not the changes they see in the glacial record are coeval with regional temperature changes. The project will include an undergraduate student in a research capacity and the data gathered in the course of this research will be incorporated into the literature for Maine\u27s Ice Age Trail (a display of Maine\u27s geologic history along public roads), as well as into classroom and public lectures.The research seems to fit well into the high risk and exploratory nature of the SGER program because it is not a certainty that the researchers can establish a reliable chronology that will be of utility for their scientific interests. A small investment of research funds, however, can help shed light on the science issues

Reconnaissance surficial geology of the Passadumkeag [15-minute] quadrangle, Maine

Maine Geological Survey, Open-File Map 81-4https://digitalmaine.com/mgs_maps/1597/thumbnail.jp

Till Stratigraphy and Late Wisconsinan Deglaciation of Southern Maine: A Review

At least two glaciations are recorded by the till stratigraphy of southern Maine. A more deeply weathered lower till is tentatively correlated with the early Wisconsinan (or older) Nash Stream Till in New Hampshire and its inferred equivalents in southern New England and Québec. The Laurentide Ice Sheet flowed south-southeastward across southern Maine in late Wisconsinan time and deposited the upper till. By about 14,000 years ago the ice sheet started to recede from the Maine coast, and the high peaks of the Mahoosuc Range emerged as nunataks in western Maine. Marine transgression accompanied déglaciation of lowland areas of southern Maine, with deposition of end moraines, deltas, and subaqueous outwash along the active ice margin, while thick clay deposits of the Presumpscot Formation accumulated on the ocean floor. The ice margin retreated quickly, reaching the marine limit in central Maine by 13,000 yr BP. The Pineo Ridge moraine system in eastern Maine, formerly thought to represent a major readvance, is reinterpreted as a glacial stillstand near the marine limit. Deglaciation inland from the marine limit in eastern and southwestern Maine occurred by recession of an active ice margin in some areas, and elsewhere by stagnation and downwasting of ice that was separated from the active ice sheet. Southern Maine was ice-free by 12,000 yr BP. but marine submergence persisted until about 11,000 years ago in the southwestern coastal lowland.On a enregistré au moins deux glaciations dans la stratigraphie du till, dans le sud du Maine. Un till inférieur, profond et altéré, est, à titre d'essai, mis en corrélation avec le Nash Stream Till du Wisconsinien inférieur (peut-être même plus ancien), au New Hampshire, et avec ses équivalents probables, dans le sud de la Nouvelle-Angleterre et du Québec. Au Wisconsinien supérieur, la calotte lau-rentidienne s'écoulait en direction SSE dans le sud du Maine où elle déposa le till supérieur. Il y a environ 14 000 ans, le retrait de la calotte glaciaire s'amorça à partir de la côte du Maine, et les plus hauts sommets du Mahoosuc Range, dans l'ouest du Maine, émergèrent. La transgression marine suivit la déglaciation des basses terres du sud du Maine, entraînant le long de la marge active, le dépôt de moraines terminales, la formation de deltas et un épandage fluvio-glaciaire subaquatique, pendant que d'épais dépôts d'argile de la formation de Presumpscot s'acumulaient sur le fonds marins. La marge glaciaire recula rapidement pour atteindre la limite marine, au centre du Maine, vers 13 000 ans BP. Le système morainique de Pineo Ridge, dans l'est du Maine, qu'on croyait relié à une récurrence majeure, est maintenant considéré comme le résultat d'une pause glaciaire près de la limite marine. Dans l'est et dans le sud-ouest du Maine. Ia déglaciation vers l'intérieur, à partir de la limite marine, s'est effectuée, dans certains endroits, par recul de la marge glaciaire et, ailleurs, par stagnation ou par fonte de culots de glace séparés de la masse principale. Le sud du Maine était libre de glace dès 12 000 ans BP, mais, il y a environ 11 000 ans BP, la submersion marine affectait encore les basses terres côtière du sud-ouest.Zumindest zwei Eiszeiten sind durch die Till-Schichtung von Sud-Maine festgehalten. Ein tiefer abgelagertes niedrigeres Till wird versuchsweise mit dem Nash Stream-Till des frùhen (Oder âlteren) Wisconsin in New Hampshire und seinen môglichen Àquivalenten in Sùd-Neuengland und Québec in Zusammenhang gebracht. Im spàten Wisconsin floB dièse laurentische Eis-Kappe sùdsùdostwârts durch Sud-Maine und lagerte das obère Till ab. Vor ungefâhr 14 000 Jahren begann die Eiskappe von der Kùste von Maine zurùckzuweichen, und die hohen Gipfel der Mahoosuc-Kette tauchten als Nunatakker in West-Maine auf. Eine marine Transgression begleitete die Enteisung der Tieflandgebiete von Sud-Maine und lagerte Endmorânen, Deltas und Unterwasseraufschwemmung entlang der aktiven Eisgrenze ab, wàhrend sich dichte Ton-Ablagerungen der Presumpscot Bildung auf dem Ozeanboden ansammelten. Die Eisgrenze wich schnell zuriick und erreichte die marine Grenze im Zentrum von Maine um 13 000 v.u.Z. Das Pineo Ridge Morânen-System im Osten von Maine, von dem man friiher dachte, es stelle einen HauptrùckvorstoB dar, wird neu gedeutet als ein glazialer Stillstand nahe der marinen Grenze. In Ost- und Sùdwest-Maine, im Inland von der marinen Grenze, fand die Enteisung statt durch Rùckzug einer aktiven Eisgrenze in einigen Gebieten und in anderen durch Stockung und Abnehmen von Eis, das von der aktiven Eiskappe getrennt wurde. Der Sùden von Maine war um 12 000 v.u.Z. eisfrei, aber marines Untertauchen dauerte weiter bis ungefâhr vor 11 000 Jahren im sudwestlichen Kùstentiefland

Reconnaissance surficial geology of the Petit Manan [15-minute] quadrangle, Maine

Maine Geological Survey, Open-File Map 74-8https://digitalmaine.com/mgs_maps/1520/thumbnail.jp

Late-Glacial and Holocene Geology of the Middle St. John River Valley

Guidebook to the geology of Northeastern Maine and neighboring New Brunswick: The 72nd annual meeting of the New England Intercollegiate Geological Conference, Presque Isle, Maine, October 10-13, 1980: Trip C-

Quaternary History of Northwestern Maine

Guidebook for field trips in the Rangeley Lakes - Dead River Basin region, western Maine: 62nd annual meeting October 2, 3, and 4, 1970: Trip E-