It is generally agreed by most investigators of Long Island stratigraphy that Wisconsin 

 glaciation is represented by two prominent terminal moraines. Both deposits consist 

 primarily of terminal moraine till, however, lacustrine and fluvial sedimentary materials are 

 also present. The two moraines are difficult to differentiate in western Long Island because 

 one is nearly superimposed on the other; however, observations from eastern Long Island, 

 where the moraines bifurcate, clearly show that the Harbor Hill Moraine is separate from 

 and younger than the earlier Ronkonkoma Moraine. The flanks of Long Island south of the 

 terminal moraines are composed primarily of outwash sand and gravel which was carried 

 southward over the then exposed shelf by numerous, melt -water fed, braided streams. The 

 time marking the end of Pleistocene continental glaciation and the start of the Holocene 

 transgression of the sea back over the shelf is variable depending on geographic location and 

 degree of isostatic rebound, but Schaffel (1971) feels that a date of 10,000 ± 1,000 years, 

 Before Present (B.P.) represents an approximation for commencement of the marine 

 transgression over the western Long Island region. 



b. New Jersey. Much of the original mapping, describing and naming of the Coastal 

 Plain strata of New Jersey was complete by the end of the 19^, or beginning of the 20^ 

 century. Most of the research effort since then has been to refine paleontological 

 correlations and to reassign various formations to different geologic ages based on new 

 evidence. Because Atlantic Highlands is less urbanized than western Long Island fewer bore 

 holes for ground water have been drilled to provide detailed vertical stratigraphy. In general, 

 the geology of the Atlantic Highlands region is less complex and varied than Long Island 

 because it lies south of maximum glacial advance and was little influenced by the 

 tremendous erosive and depositional effects of the continental ice sheets and their 

 accompanying melt-water streams. The most exhaustive study of the Sandy Hook area was 

 done by Minard (1969). Minard provides detail on the surfical geology of the area and also, 

 by use of deep auger drilling equipment, has provided detailed stratigraphy in the third 

 dimension along Sandy Hook into Lower New York Bay. Consequently, only a summary 

 will be included in this paper. 



At least 10 Coastal Plain formations are well exposed in the northern New Jersey area 

 where a highland has developed by differential erosion to a maximum relief of over 

 240 feet. The strata in northern New Jersey are Upper Cretaceous and Tertiary in age and 

 are stratigraphically higher and therefore geologically more recent than the Coastal Plain 

 formations underlying western Long Island. The aggregate thickness of the exposed Coastal 

 Plain units is about 500 feet (Minard, 1969) but, no deep bore hole data are available to 

 confirm depth to the crystalline bedrock. Total subsurface thickness is based on geophysical 

 refraction data and projection of bedrock from close-in holes. Extrapolation of data from 

 seismic refraction study by Oliver and Drake (1951) to the New Jersey area indicates that 

 the basement surface is perhaps 1,200 feet beneath Sandy Hook and sloping to the 

 southeast. 



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