make up much of the material in Frying Pan shoals. It is especially 

 prominent in Long Bay and in Frying Pan shoals; in Onslow Bay, it is 

 interspersed with large patches of coarser surficial deposits, reworked 

 substrate material, and exposures of pre-Holocene strata. 



Type A sand characteristically contains more than 90 percent quartz 

 grains; most grains are of angular form and subspherical shape (Fig. 16). 

 Silt is present in most places but normally in very small quantities. 

 Calcium carbonate skeletal material, such as small-sized echinoid frag- 

 ments, foraminiferal tests, bryozoa, ostracod carapaces, and mollusk 

 shells, comprises the bulk of the remaining particles. The mollusks are 

 mostly minute larval and immature forms or representatives of small spe- 

 cies; large mollusk shells and shell fragments are uncommon. Type A sand 

 is typically light brownish gray, close to Munsell Soil Color Code 10 yr 

 6/2 (Munsell Soil Color Charts, 1954 ed., Munsell Color Co., Inc., Balti- 

 more, Md.). In bulk samples the color is usually uniform, but on close 

 inspection dark specks can be discerned in the matrix. These are mostly 

 particles of black and brown phosphorite and blackened shell material. 



Type A sand cannot be readily differentiated from the other fine sand 

 types without reference to faunal content (discussed in Sec. IV). Slight 

 differences in color, carbonate content, and mode of occurrence are of 

 some value in gross comparison but are not definitive. 



(2) Type B . Very fine to fine, well-sorted sand occurs in all 

 cores that penetrated seismic reflection unit III (Fig. 6) and is appar- 

 ently characteristic of the upper sampled parts of this extensive deposit 

 underlying southern Onslow Bay and the eastern Long Bay area. Type B 

 sand (Fig. 17) is generally very uniform in size and character from place 

 to place and in depth. Calcium carbonate is a common to abundant con- 

 stituent of type B sediment in many places, reaching a frequency of over 

 25 percent locally. Most, if not all, of this calcareous material is 

 biogenic, consisting mostly of ostracod carapaces, echinoid spines, 

 foraminiferal tests, and finely broken mollusk shells. A number of 

 cores, containing type B sediment, however, have very little, if any, 

 calcium carbonate and no calcareous fossils but do contain sparse phos- 

 phatized teeth and bone fragments. All but two of these cores are closely 

 grouped together in the area between Moores Inlet and Carolina Beach Inlet. 

 Phosphorite in type B sand is usually rounded, brown to black opaque 

 grains, often with a high polish and in the form of phosphatized teeth 



and bone fragments. Sizes of the grains are near that of the sand matrix 

 (Table 3) though the bone fragments are often larger. Glauconite is also 

 present in small quantities and generally of a size near that of the finer 

 half of the sand matrix. 



Type B sand is grayish brown (2.5 yr 5/2) to light brownish gray 

 (2.5 yr 6/2) and uniform. Dried samples show a slight cohesion and often 

 form friable lumps. 



(3) Type C . Type C sand occurs in many cores between Lockwoods 

 Folly Inlet and the South Carolina border. This area is underlain by 



39 



