1977 0 
Schold, G. P. (1977) Analysis of an indigenous foraminiferal biocenosis from Buttonwood 
Sound, Florida Bay. M. S. Thesis. Duke University, Durham, NC. 87 pp. 
(DATE OF SAMPLING UNKNOWN OR NOT APPLICABLE.] Samples of Thalassia testudinum 
(Konig) and short cores of sediment were collected over short lateral and vertical 
distances in Buttonwood Sound to study distribution patterns of the indigenous 
foraminiferal biocenosis. A rope cross, consisting of rays 50 meters in length, was 
staked to the bottom. Samples were collected at intervals of 5, 50, 500, and 5,000 cm 
from the center of the cross along each ray. Very few foraminifera were found to be 
living on T. testudinum and consequently the quantitative analysis was essentially 
restricted to those foraminifera that were living either on or within the sediment. 
Species diversity indices and factor-vector analysis were used to analyze the 
foraminiferal biocenosis. Factor-vector analysis is a mathematical model used to 
determine causal relationships existing between species (R-mode analysis) and between 
samples (Q-mode analysis). Ten vectors were selected in the R-mode factor-vector 
analysis that accounted for approximately 94% of the total information contained in the 
data matrix. The average Shannon-Wiener species diversity index accounting for the 
foraminifera living in the upper 2 cm of the sediment cores was 2.48, whereas the 
average species diversity index in the next lower 14 cm of sediment from the same 
cores was 2.12. Archaias angulatus (Fichtel and Moll) was the only numerically 
dominant species in the study area. Species diversity indices suggest that the 
environment of the study area was relatively unstable, resulting in broad niches 
populated by a few abundant species. Variations in species diversity were attributable 
to the distribution of a large number of rare species. The growth density of T. 
testudinum might have been in part responsible for the rather uniform pattern of 
species diversity. Thalassia testudinum traps sedimentary particles of a size that 
depends on its density, thus producing a somewhat homogenous substrate. Because the 
rope cross was positioned in an area characterized by a fairly constant growth density 
of T. testudinum, distribution of the various sizes of sediment was very similar 
throughout the study area to account for the variation in biotic/abiotic response that 
was by both R-mode and Q-mode factor-vector analysis. 
1977 0 
Steinen, R. P., R. B. Halley and S. L. Videlock (1977) Holocene dolomite locality in Florida 
Bay. Am. Assoc. Petrol. Geol. Bull. . 61(5):833. 
[ABSTRACT ONLY. DATE OF SAMPLING UNKNOWN OR NOT APPLICABLE.] Dolomitic mud 
has been identified in the unlithified subsurface Holocene sediments recovered from 
Cluett Key, Florida Bay. The dolomite is in the lower one third to one-half of the 
slightly greater than 3-m thick carbonate mud, sand, and peat accumulation. In this 
interval the dolomite is estimated to comprise up to 40% of the sediment and is present 
as dolomite grains and rhombs smaller than 2 jx. The dolomite is poorly ordered and 
calcium-rich (Ca 0 56 _ 0 60 Mg 0 400 44 C0 3 ). A second type of dolomite is stoichiometric 
and is in small amounts (less than 50%) in some samples. This type of dolomite is 
believed to be similar to the detrital dolomite identified by earlier workers in Florida 
Bay. Dolomite is common in cores from Cluett Key, but is absent or in insignificant 
amounts in the adjacent subtidal mudbanks that surround the inland. The dolomitic island 
mud is underlain by peat with a 14 C age of 3879 ± 70 yrs BP. The dolomite is 
completely unlithified and lacks cementation features associated with supratidal 
dolomites from elsewhere in South Florida and the Bahamas. It appears in both 
supratidal and subtidal (subaqueous). The origin of this dolomite is currently under 
investigation. Its distribution suggests a relation with some island process, most likely 
the formation and trapping of brackish and hypersaline ground waters in the low- 
permeability (10 md average) island muds. Brackish ground water (0 to 30 %o total 
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