Perkins, four marine-deposited units (Q1 through Q4) were recognized in Upper 
Pleistocene rocks underlying the Bay. Differentiation between units was based upon the 
recognition of unconformities and subaerial features associated with sealevel 
lowstands. Antecedent topography affected Pleistocene sedimentation. Contour maps of 
each unit depict the topography, thickness, lithofacies, and paleoenvironment during the 
time of deposition. Configuration maps reveal the Cape Sable and South Florida Highs 
were covered with siliciclastics eroded from the mainland. The Pleistocene shelf-edge 
and an open-marine platform were among the major factors influencing sedimentation in 
South Florida and Florida Bay during Q1 time. Sealevel transgression during Q2 time 
resulted, in part, in a transition from clastic sedimentation to in situ carbonate 
production and deposition. In Q3 time a barrier reef grew on the Pleistocene shelf-edge. 
A lagoonal back-reef area (Florida Bay) developed leeward of the barrier. Cores reveal 
that reef mounds, and patch reefs in the back-reef, did not begin to flourish until the 
beginning of Q3 time. Fluctuation in sealevel greatly affected facies deposition and patch 
reef growth during Q3 a Q4 time. East Key patch reef initiated growth from a Q3 reef 
mound subsequent to a minor sealevel drop; subaerial exposure of the reef at the end of 
Q3 time resulted in the death of the reef. Lignumvitae Key patch reef growth probably 
was initiated in Q3 time and, similar to the barrier reef, continued growth throughout 
Q4 time. 
1985 - 1987 
Schropp, S. J., F. G. Lewis, H. L. Windom, J. D. Ryan, F. D. Calder, and L. C. Burney (1990) 
Interpretation of metal concentrations in estuarine sediments of Florida using aluminum as a 
reference element. Estuaries . 13(3):227-35. 
Metal contamination of estuarine sediments is an increasing problem in Florida and 
elsewhere as urbanization extends into previously undeveloped areas. Effective 
estuarine management practices require scientifically valid tools to assess the extent 
of estuarine contamination. Interpretation of anthropogenic metal contributions has been 
hampered by the fact that natural metal concentrations in sediments vary by orders of 
magnitude in different sediments. Normalization of metal concentrations to a reference 
element, Al, appears to be a promising method for comparing estuarine sediment metal 
concentrations on a regional basis. This paper describes an interpretive method based 
on the relationship between sediment metals and Al derived from statewide data on 
natural estuarine sediments in Florida. Data from the Miami River and Biscayne Bay 
were used to demonstrate the interpretative method. Sediment samples were collected 
from 1985 to 1987 from 28 coastal sites and analyzed for Al, Cr, Ni, Cu, Zn, As, Cd, 
Hg, and Pb. Analytical methods and quality assurance protocols are described in the 
paper. 
1985 - 1987 
Bosence, D. (1989) Surface sublittoral sediments of Florida Bay. Symp. on Florida Bay: A 
Subtropical Lagoon. Miami, FL. June, 1987. Bull. Mar. Sci. . 44(1 ):434-53. 
Results of detailed analysis of sediments from the restricted Cross Banks area and the 
more open marine Buchanan Keys area are discussed as well as previous work. 
Sediments of the Cross Banks area were composed principally of mollusk and 
foraminifera grains with a pelleted, silt-sized matrix. Textures on the banks varied 
from windward mud-pebble-conglomerates, packstones and grainstones to bank-top 
leeward, and lake, wackestones and mudstones. The latter was deposited in patchy to 
dense seagrass beds. Sediments of the Buchanan Banks area comprised grains of 
Halimeda, coral and lithoclasts in addition to mollusk and foraminifera grains. Windward 
facies were packstones, grainstones and some Porites framestones. Bank top and 
leeward margins accumulated peloidal mudstones and wackestones under seagrass 
cover. Lake floors were bare but have a thin packstone covering. In both areas, facies 
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