parameters that are themselves interrelated. They conspire to form island ground 
water that not only differs from seawater but also can react with the island sediments 
to change the character of ground water. In this manner, island ground waters serve as 
geologic agents, hastening the alteration of marine carbonate sediments to limestone 
and dolomite. This study was done in 1976. 
1976 0 
Hovorka, S. D., P. E. Luttrell, and T. D. Murphy (1976) Facies relationships and depositional 
history of south Florida carbonate mud banks. Geol. Soc. Amer. Abs. . 8:23-24. 
[ABSTRACT ONLY. DATE OF SAMPLING UNKNOWN OR NOT APPLICABLE.) Interior Florida 
Bay consists of shallow 1-3 m deep semicircular basins separated by a network of 
elongate shoals (banks). Low mangrove islands (keys) are developed along the bank 
crests. Geometry of Holocene carbonate sediments is based on data from probes and 
cores taken along profiles across several banks and keys. Comparison with surficial 
sediment characteristics permits recognition of facies in the cores. Facies relationships 
have been used to interpret depositional history and evolution of the banks and their 
associated keys. Mangrove peats developed on the irregular Pleistocene surface during 
post-Pleistocene sea level rise. As flooding continued subtidal Thalassia meadows 
became established on minor topographic highs. The dense grass trapped carbonate 
muds resulting in vertical accretion and development of the bank system variations in 
intertidal facies are associated with bank crests. Where tidal circulation is adequate 
and salinities are near normal marine the branching finger coral Porites divaricata 
forms dense mats. These corals are absent in the bay interior where salinities are 
lower and more variable. In these areas, mangrove seedlings become established along 
bank crests contributing to island development. Island margins may be characterized by 
shell berms and mangrove peats. Island interiors have marshes developed on supertidal 
storm washovers and shallow central ponds. These ephemeral ponds are filled with 
muds and have thin surficial blue-green algal mats. Facies evolution of Florida Bay 
banks provides an excellent model for shallow, low energy, humid climate carbonate 
platform sedimentation. 
1 976 
Layman, J. W. (1977) Acid insoluble residues of the carbonate sediments of Northwest 
Florida Bay, South Florida. M. S. Thesis. University of Toledo, Toledo, OH. 78 pp. 
Sixty-seven surface grab and core samples, collected from the carbonate sediment 
forming environment of northwest Florida Bay, were analyzed to determine the 
amounts, composition, textures and sedimentation patterns of acid insoluble residues. 
The characteristics of the acid insoluble residues and their sedimentation patterns were 
then related to ten depositional sub-environments which were determined and classified 
according to what are believed to be the dominant physical environmental controls: 
depth of water, tidal current activity and exposure to wave action. The tidal channels 
were divided into the outer, central and inner sub-environments. The mud banks were 
divided into the outer, Middle Ground, central and inner sub-environments, and the 
mainland shore face was divided into the Gulf exposed, outer and central sub¬ 
environments. The weighted average amounts of acid insoluble residue coarser than 8.0 
<j> ranged from 1.5% on the Gulf exposed shore face to 9.5% on the Middle Ground banks. 
The amount of sand-sized acid insoluble residue decreased eastward from 2.3% on the 
higher energy Middle Ground banks, which are exposed to the Gulf of Mexico, to 0.8% 
in the lower energy inner tidal channel sub-environment of Florida Bay. Silt-sized acid 
insoluble residues were highest on the banks and averaged approximately 5.5% for the 
outer, central and inner banks. The Middle Ground banks contained 7.2% silt-sized acid 
insoluble residue. Quartz was the dominant constituent of the acid insoluble residues and 
ranged in size from 0.0 to 8.0 <J>. Sponge spicules occurred as whole and fragmented 
221 
