extend in an irregular line south to Cape May city. The tip of Cape May penin- 

 sula from Cape May city west to Delaware Bay is also a headland where pre- 

 Holocene sediments are directly exposed to coastal erosion. 



The sea floor contours in Figure 3 show a very complex pattern, but the 

 general ridge and swale topography trends northeast -southwest east of about 

 longitude 74°45' W., whereas to the west the shoals are arcuate and parallel 

 the Cape May coast. Five Fathom Bank (shown by the 2-meter (-36 feet) contour 

 in Figure 3) is an exception to either fabric by its north-south orientation 

 and probably owes its origin to processes that are different from those that 

 form and modify most shoals in the area. The shoals on the Delaware shelf west 

 of the Delaware Channel are quite different in orientation by trending to the 

 northwest . 



Sediments , 



Sediments recovered from cores of the study area can be divided into two 

 general age groups. The younger group consists of Holocene marine sediments 

 which are distinguished by their small content of invertebrate remains; the pre- 

 sumably older group of sediments is mostly barren of animal remains. The most 

 abundant Holocene deposit is a clean, pale-brown quartz sand, locally with ad- 

 mixtures of granules and pebbles. Sand size ranges from fine to very coarse 

 (Wentworth Scale in Table 1). Sorting is predominantly poor especially in the 

 coarser sand faces. Also included in the presumed Holocene deposits are silt, 

 clay, and silty, sandy gravel which are probably relict transgressive back- 

 barrier or reworked deposits from older substrate. 



Below the Holocene sediments is a diverse group of pre-Holocene sediments 

 consisting of sands, sandy gravel, silt, and clay. These deposits are complexly 

 distributed with little vertical or lateral continuity. Although pre-Holocene 

 sediments of similar character occur throughout the area, available data suggest 

 that these deposits are not directly connected but rather that lithologic simi- 

 larities are due to common source areas and recurrence of similar depositional 

 conditions. The heterogeneous character and highly discontinuous distribution 

 of these sediments suggest fluvial deposition. Nonmarine depositional condi- 

 tions are also suggested by the absence of any marine organic remains, although 

 this could be due to leaching. 



Sediments recovered by cores taken during the ICONS survey are described in 

 the visual core logs of Appendix A. Grain-size data for selected surveys are 

 presented in Appendix B. Most of the sediments can be grouped in a number of 

 characteristic types (summarized in Table 2) ; letters keyed to these types are 

 used in the log descriptions (App. A) to identify sediments which correspond 

 to the general character of a given type description. The similarities between 

 sediments in a particular group do not necessarily indicate a stratigraphic 

 relationship, although this may be true in some cases. Sediment types A, B, 

 and the type C sediments containing shell are considered Holocene; the remaining 

 types are probably of pre-Holocene age. 



10 



