Abstract The New York bluffs of Lake Erie, which stretch northeastward 100 km from the Pennsylvania border, and those of Lake Ontario, which extend eastward 212 km from the Niagara River along the south shore of the lake, expose one of the most continuous sets of glacial drift in the northeast. The Erie bluffs are predominantly Devonian shale. However, the shale is mantled by sandy-silt till remarkable for its lateral uniformity in texture, but with distinct “down-ice” trends in lithologic properties relating to the regional bedrock or glacial reworking. Proglacial lacustrine silt, clay, and sand, deposited in 90 to 50 m of water in glacial Lakes Whittlesey and Warren between 13.5 and 12 ka, overlie the till. The bluffs of Lake Ontario are cut only sparingly in Ordovician red sandstone and shale and expose three major lithostratigraphic units. A lower red or pink sandy-till sheet is overlain by widespread gray and red glaciolacusrrine silt and clay. These fines provide major input to a younger, sillier, purplish-gray or gray till marked by both massive basal facies and upper subaqueous-flow or basal melt-out diamicton. A blanketing glaciolacustrine sequence occurring in the lower, nondrumlin areas is largely related to glacial Lake Iroquois. Locally, proglacial sands, lenses of flow till, or stone concentrations indicate a short readvance during lake formation. The two major tills of the Lake Ontario bluffs correlate with a similar sequence in adjacent Ontario, Canada. These, in turn, are tied to the Halton Till of the Port Huron advance. The lower till sheet of the United States Erie shore is related to a preceding advance, which is tentatively identified as the Lake Escarpment glaciation, and the Wentworth Till of nearby Canada.

Grove Karl Gilbert (1843–1918) began his work in professional geology in 1869 as “local assistant” on the newly established Second Geological Survey of Ohio (the “Newberry Survey”). He worked without salary but received $50 per month for expenses. Gilbert investigated Williams, Fulton, and Lucas Counties, the three most northwestern counties adjacent to the Michigan State line. The area extended from Indiana on the west to Toledo at the western end of Lake Erie. His originality, analytical power, and clear verbal and graphic exposition, which were the distinguishing characteristics of his work throughout his career, are completely exhibited in this his earliest work, published in nine articles and reports from 1871 to 1874. Gilbert’s maps of glacial geology of Williams and Fulton Counties are noteworthy for their detail and accuracy. He was the first to discover and map the major end moraines of the Maumee basin, from east to west (youngest to oldest): the Defiance, Fort Wayne, and Wabash Moraines. Gilbert found that the drift sheets of the moraines were actually multiple and that the uppermost drift was draped over a core of older material, a concept not to be widely recognized until almost 50 years later! Gilbert discovered the continuity and mapped the beach ridges now called, from highest to lowest, Maumee, Whittlesey, and Warren. After distinguished work in the West from 1871 to 1881, Gilbert returned to the East and, among other projects, began to study the glacial geology of New York, especially Niagara Falls and the Lake Ontario raised beaches. In his classic study of the origin and retreat of Niagara Falls, he concluded that the Horseshoe Falls had retreated at the rate of 5 ± 1 ft/yr. Gilbert’s other work in the Ontario basin was on the uplifted shorelines of Lake Ontario, the character and amount of their later tilting, and the surface features and drainage channels of the Rochester region. He was impressed by the boulder pavements in the till and by the evidence of glacial and postglacial folding and faulting, on which he published several papers.

Abstract The craton was the focal point for the development of glacial geology in North America. Glacial deposits in the Ohio Valley were illustrated and described early in the century by Volney (1803, 1804), who, however, did not understand their origin and Drake (1815, 1825), who attributed the origin of erratics to icebergs. The iceberg hypothesis for the deposition of at least a part of the glacial drift persisted until late in the century. The first glacial geologist in America was Charles Whittlesey who made early but significant studies in several states in the 1840s and 1850s. Whittelsey published the earliest maps and sections in America showing end moraines, kettle holes, and the glacial boundary. He was the first in America to classify drift, describe the “Forest Bed,” and trace drift in the subsurface. In the 1860s and 1870s, the state geological surveys assumed a leadership role in glacial studies. Most notable of these was the Ohio Geological Survey directed by John Newberry, who was recognized as the leading glacial geologist of his time. An understanding of glacial lobes, glacial erosion of lake basins, moraines, multiple glaciation, and climatic change developed during this period. In the 1880s, the U.S. Geological Survey under the guidance of T. C. Chamberlin established dominance in glacial studies of a regional nature. Chamberlin’s recognition that the glacial drift represented several glacial advances separated by warmer, nonglacial periods led to a formal classification for the North American Pleistocene. By 1886, Chamberlin considered his phase of glacial studies essentially complete, and he assigned the responsibility of detailed moraine mapping to one of his assistants, Frank Leverett. Leverett proceeded to map in considerable detail the glacial drift and related geomorphic features of the Illinois and Erie lobes, covering an area extending from Iowa to New York. Leverett’s detailed mapping, keen observations, and ability to synthesize large volumes of data provided a fitting climax to nineteenth century glacial studies.

Abstract Preeminent nineteenth century American geologist James Hall was not only one of the most competent and ambitious paleontologists and stratigraphers of his day, he also had a firsthand early grasp of midwestern as well as Appalachian geology. In 1841 he joined David Dale Owen for a tour of the Ohio Valley to see how far west the New York State stratigraphie divisions could be extended. He was warmly rewarded. With similar motivation, he also joined the Foster-Whitney-Whittlesey Lake Superior Survey of 1850-51. Then, when the New York legislature terminated his salary during one of its feuds with the irascible paleontologist, Hall accepted an invitation to organize a survey for the young state of Iowa in 1855-59; and in 1856 he assumed an advisory role to the embryonic Wisconsin Survey. He also became a consultant for several other states and had helped to instigate the first Hayden-Meek western Survey to the South Dakota Badlands (1853). Hall’s unique acquaintance with cratonic as well as Appalachian stratigraphy and structure equipped him to recognize the fundamental differences between cratons and orogenic belts. The great thickness and structurally complex nature of Appalachian Paleozoic strata then led to development of his famous theory of mountain building, which was first expounded in the 1857 AAAS presidential address soon after his princi-pal midwestern experiences. Although Hall’s inferred simplisitc causal relationship between sediment thickness and mountain building proved wrong, the observation that thick strata are somehow associated with active tectonism was of fundamental importance and is still very much

Outwash deposits in the Ohio Valley that were thought to be alluvium were illustrated by Volney in 1803. Drake (1815) proposed an iceberg origin for Wisconsinan erratics in Ohio. Hitchcock (1841a) in Massachusetts reviewed the glacial theory of Agassiz favorably, and in Ohio, St. John (1851) wrote in detail on the subject. Ice sheet origin of drift was widely and generally accepted by 1865. Multiple glacial advances, many of which later turned out to be Wisconsinan, had been noted by Lyell (1849), Whittlesey (1866), Worthen (1868), Orton (1870), Winchell (1873), and Newberry (1874). Chamberlin (1878) gave the first detailed description and analysis of the different ages of surface drifts in the Kettle Moraine region. After Chamberlin introduced the term Wisconsin (1894 Wisconsin (1895), Leverett (1899) divided the Wisconsinan into early, middle, and late, and Leighton (1931) assigned the Iowan to the Wisconsin and gave the names Tazewell, Cary, and Mankato to the early, middle, and late substages of Leverett. Rock- and time-stratigraphic terminology of the Lake Michigan Lobe was defined by Frye and Willman (1960), and the terms Altonian, Farmdalian, Woodfordian, and Twocreekan were introduced. Other geologists have recently used this classification to differentiate the drift of other lobes.

ABSTRACT The Erie lakeshore in Pennsylvania, west of the city of Erie, has many geological features that are ripe for study, teaching, and use as a vehicle for public science outreach. Features and processes on display include rapid slope failure and erosion of lakeshore bluffs, Pleistocene till in the bluffs, well-developed ancient sandy beach ridges atop till, and thin Upper Devonian sandstones that were deposited by storms. A wide variety of sedimentary, igneous, and metamorphic rocks can be found among cobbles eroded from till and rounded on lakeshore beaches, providing opportunities for teaching the identification of rocks, minerals, and Paleozoic marine fossils. Small fans at the bases of lakeshore bluffs have morphologies derived from distinct modes of sediment transport and deposition, with the potential to serve as analogs in better understanding large submarine fans. In winter, ice volcanoes can occur on the shoreline. Opportunities for teaching about geologic time are provided by localities where recent sedimentary processes, Pleistocene deposits, Paleozoic sedimentary rocks, and Precambrian igneous and metamorphic rocks can all be seen.