Evidence for the presence of the Hudson (submarine) Channel off Lower New York Bay 

 apparently was first discovered during the 184244 hydrographic leaddine surveys 

 (Lindenkohl, 1885), and was first described in professional geologic literature by 

 James D. Dana in 1863. (Dana, 1890.) The area was described by early mariners as a "series 

 of mud holes" but it was Dana who realized the significant alignment of the mud holes with 

 the course of the subaerial Hudson River. It was his hypothesis that the submarine channel 

 represented, during earlier geologic periods, the channel through which the river flowed 

 when either the land surface was higher or sea level was significantly lower. Dana's acute 

 observation provided the impetus for others to carefully survey the Hudson River region and 

 started others examining channel-canyon systems elsewhere and formulating ideas for their 

 origins which is still not resolved. An 1882 survey gives more detailed topographic 

 expression of the channel. A second hypothesis on the channel origin was proposed at this 

 time and suggested that it was produced "by a break in the strata." However, this theory of 

 a fault or zone of crustal weakness projecting southeast from New York was not 

 substantiated by the peripheral geology in either New Jersey or on Long Island, and thus 

 was rejected. Later surveys traced the channel from its head in Lower Bay some 85 nautical 

 miles across the shelf where it leads to the head of the Hudson Canyon at the shelf edge. 

 (Stearns, 1969), (Veatch and Smith, 1939.) 



Modifications of the channel by ocean disposal of solid materials from New York City 

 have greatly altered the topography since the first detailed hydrographic chart was produced 

 in 1845. Several anomalous circular mounds at least 20 feet high from the sea floor are 

 situated in the depression of the Hudson Channel just east of Sandy Hook. Similar features 

 are also present to the northeast adjacent Ambrose Light Tower and are referred to as 

 Diamond Hill. (See Figure 4.) These sea floor features are the result of ocean disposal of 

 solid material from the New York metropolitan area and will be discussed later. 



A second but smaller submarine channel exhibits bathymetric expression in a southeast 

 orientation from about the midpoint of Sandy Hook. It was named the Highland Channel 

 on a hydrographic chart by Murray, 1888 (Veach and Smith, 1939) and appears to connect 

 with the Hudson Channel in 90 feet of water south of Castle Hill. Considering its relative 

 position the channel is most likely an extension of the ancestral Raritan River which 

 apparently flowed eastward across the exposed shelf during Late Pleistocene, before the 

 growth and accretional development of Sandy Hook. Topographic expression of the channel 

 is lacking west of Sandy Hook in Lower New York Bay; it probably was present and has 

 since been filled by the Holocene redistribution of sediment and especially by sand carried 

 by littoral currents around the tip of Sandy Hook. MacClintock and Richards (1936), 

 reported the presence of the buried Raritan Channel from borings along a proposed bridge 

 route, between New Jersey and Staten Island, and noted that the base of the channel had 

 been excavated 170 feet below sea level into the Raritan Formation. The channel was filled 

 with sand, gravel and silt. The strikingly straight coastline of the Atlantic Highlands (Fig. 4) 

 perhaps owes its origin to lateral stream bank erosion by the Pleistocene Raritan River. 



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