The Late Quaternary Construction of Cape Cod, Massachusetts: A Reconsideration of the W. M. Davis Model

Abstract

Like the W. M. Davis construction o f Cape Cod published in 1896, this special paper suggests that the Cape was formed by glacial deposition during the late Pleis tocene and by marine and aeolian processes during the Holocene. It differs, however, from the Davis model in several significant ways. For example, Davis proposed that the lower Cape extended 4 km east o f its present location, and that only 4,000 yr were needed for the lower Cape to attain its present form. This study indicates that the glacial Cape extended as far as 7 km east of its present position, and that it took about 9,500 yr for the Cape to attain its present morphology. Davis also believed that the detritus eroded from the sea cliffs on the east side of the lower Cape was trans ported northward to form the Provincetown Hook. On the other hand, this book indi cates that, as a result o f the subaerial exposure o f Georges Bank from 9,500 to 6,000 yr ago, littoral drift to the north was inhibited and sediment was transported south ward to fill a depression at the Cape's elbow. Since Georges Bank became submerged about 6,000 yr ago, however, littoral drift shifted partly to the north, leading to the construction of Provincetown Hook, a process that is still taking place today. The bulk o f material (86%) eroded from the cliffs along the east side of the lower Cape during the last 6,000 yr was transported northward. Of the remainder, 7% was used in the construction o f the beaches and offshore bars fronting the cliffs, and the remaining 7% was incorporated into the spits and barriers south of the cliffs. During the last 70 yr, the eastern Cape cliffs have been retreating at an average rate of 0.8 m a-1, a rate enhanced by a relative rise in sea level of about 2 to 3 mm a-1.

Spatial ecology and habitat selection of eastern hognose snakes

“…The Province Lands consist of postglacial deposits of coastal sediments carried north by long‐shore currents. Over time, predominant marine and aeolian forces gave the hook‐like tip of the peninsula its distinctive spiral shape and formed the existing parabolic dune landscape (Uchupi et al ). Soils in the Province Lands consisted almost entirely of sand.…”

Pleistocene hydrology of North America: The role of ice sheets in reorganizing groundwater flow systems

“…Pleistocene sea level fluctuations mimicked a sawtooth pattern (Figure 2a), decreasing slowly with the slow growth rate of ice sheets and increasing rapidly with the much higher rate of melting. On the continental shelf in New England, sea level fluctuations were complex because of the propagation of a flexural bulge (Figure 2b) [ Oldale , 1988; Barnhardt et al , 1995; Uchupi et al , 1996; Oldale et al , 1993]. The formation of large depressions or moats created by the rapidly retreating ice sheet on the continental shelf in the latest Pleistocene submerged much of the southern Maine coastline today (as evidenced by the glaciomarine Presumscott formation [ Oldale and Coleman , 1990]).…”

“…This could have caused hydrofracturing of shale units and may help to explain the occurrence of fresh water in confining units at the margins of the Illinois and Michigan basins [ McIntosh et al , 2002]. As the Laurentide Ice Sheet retreated during the late Pleistocene (Figure 4b), numerous proglacial lakes formed across the North American craton [ Teller and Kehew , 1994] and on the Atlantic continental shelf [ Uchupi et al , 1996, 2001; Uchupi and Mulligan , 2006]. These may have also been an important source of recharge to confined aquifer systems [ Marksamer et al , 2007].…”

Vegetation variation across Cape Cod, Massachusetts: environmental and historical determinants

“…In many regions, attempts to evaluate historical influences on modern vegetation are limited by a lack of information on landscape changes over time. In contrast, considerable information is available about the geological (Oldale, 1992; Uchupi et al ., 1996), palaeoecological (Winkler, 1985; Patterson & Backman, 1988; Tzedakis, 1992; Motzkin et al ., 1993; Parshall et al ., 2003) and human history of Cape Cod (e.g. Kittredge, 1930; McManamon, 1984; MHC, 1987; Friedman, 1993; Dunford & O'Brien, 1997; Holmes et al ., 1997), providing critical historical perspectives for our studies.…”