Nonmollusk contributors to the carbonate fraction of Type A sediments are ecliinoid 

 spines and fragments, barnacles, bryozoans, and microfauna. Echinoid- particles are rare and 

 sliow signs of recent breakage. Fragments of barnacles are common, but are rarely more 

 tlian a few percent of the sediment. This contrasts sharply witli the high abundances of 

 barnacles from the nearshore area near Fort Pierce, Florida. (Meisburgcr and Duane, 1971.) 

 Lunulutiform bryozoans are occasional constituents of Type A sands and do not contribute 

 significantly to sediment volume. Foraminifera, mostly benthonic and a few planktonic and 

 occasional ostrocods comprise tiie calcareous microfauna. 



Calcareous fecal pellets and oolitic grains (ooids) are also minor components of Type A 

 sediments. Ooids frequently account for 5 percent and occasionally up to 15 percent of the 

 carbonate fraction. Single ooids are pohshed and smooth and vary in color from black to 

 reddish brown and sometimes white. Petrographic analysis of ooid thin sections shows that 

 nuclei are (in order of decreasing frequency): quartz grains, pellets, mollusk fragments, and 

 whole gastropods. Multinucleate ooids are also present, with one or more smaller ooids 

 acting as one of the nuclei. Oolitic coatings are often superficial and high relief parts of the 

 quartz nucleus are exposed. A complete range from well developed oohtes to quartz grains 

 with tiny amounts of carbonate in conchoidal hollows suggests grains have undergone 

 abrasion subsequent to formation, rather than incomplete initial formation. Additionally, all 

 grains lack the outer coating of acicular crystals common to ooids found further offshore 

 (Terlecky (1967), Maclntyre and Milliman (1970), suggesting a different history and 

 perhaps a different age. Aspects and significance of the ooids to sediment transport and 

 history of the Cape Canaveral Inner Continental Shelf have been presented elsewhere. 

 (Field, Meisburgcr and Duane, 1971) (Pilkey and Field, 1972.) 



c. Type C Sediment. Sediments termed Type C are gray and brown, poorly sorted 

 muddy shell gravels and silty gravelly sands. Photos of representative Type C sediments are 

 shown in Figure 13. The chief characteristic of Type C deposits is the broad range of grain 

 sizes, due both to admixtures of fines (silt and clay) with grains of medium size and larger, 

 and to concentrations of fragmented shell debris which extend the size range on the coarse 

 side. Color is primarily light gray, gray -brown, brown (10 yr. 7/1 through 10 yr. 5/3) and 

 occasionally white and is a result of the abundance and nature of the mud fraction. Silt 

 grains are from both terrigenous and calcareous sources; clay-size particles are chiefly 

 terrigenous with minor amounts from carbonate sources. 



The sand fraction of Type C sediments is similar in gross composition to Type A 

 sediments; however, particle characteristics and specific fauna are different. Both 

 terrigenous and bioclastic sand grains lack the high degree of rounding poUsh that indicates 

 recent abrasion of Type A sands. Quartz grains retain the same shape and roundness but 

 surfaces have a lower luster and are frequently etched and pitted. Shell fragments are more 

 angular. Complete shells are not highly abraded at the umbo like many Type A shells, a 

 characteristic caused by transport in a high energ)' environment such as the Uttoral zone. 

 (Molnia, 1971.) 



Of the fauna common to Type C sediments, Anadara sp. is the most characteristic. 

 Anadura transversa (Say) and Anadara notabilis (Roding) are widespread in the study area 

 and are commonly found in quantity. Other fauna include Mulinia lateralis, Aequepecten 

 sp., barnacles, , microfauna and fragments of whelks. Relative abundance and areal 

 distribution of these and less abundant fauna are listed in Table 2. 



33 



