1 967 
Tabb, D. C., T. R. Alexander, T. T. Thomas, and N. Maynard (1967) The physical, biological, 
and geological character of the area south of C-111 Canal in extreme southeastern 
Everglades National Park. Final Report for Contract 14-10-1-160-11. Rosenstiel School of 
Marine and Atmospheric Science, University of Miami, Miami, FL. 55 pp. 
A topographic map of the region was constructed using the elevation of the periphyton 
(fibrous algal growth) on plant stems as an indication of the depth of seasonal flooding. 
These depths were, in turn, converted to elevations (i.e., the deepest flooding 
represented topographic lows and the shallowest flooding indicated topographic highs. 
Variations in these measurements from station to station represented approximate 
contours. Maximum ground-level variation observed in the area was 8.5 in. Salinity 
observations show that the freshwater (0.0 to 5.0 %o) zone extends completely 
across the study area from east to west and covers 35.6% of the 45.5 square mile land 
area studied. They also showed that salinity of 20 %o and higher exist in the canal 
below the plug at Highway 1 while the water immediately above the plug has no 
measurable salinity. Studies of animal distribution indicate that freshwater animals 
were found over 60.0% of the total land area. Studies of flowering plants indicate that 
freshwater species cover 42.4% of the land area. Mature hammock growth formed by 
these species indicate long-term freshwater conditions. Studies of unicellular plants of 
the periphyton show that freshwater forms cover 36.0% of the area under the 
observed dry season conditions. The nature of the sediments was determined by x-ray 
diffraction techniques and show that 68.2% of the study area was covered by pure 
calcite marl, thus indicating a long period of freshwater conditions. It is concluded that 
these studies, which were arrived at separately by different investigators, offer 
convincing proof of the freshwater character of soils, plants and animals of about 50% 
of the total land area within the study area. The study of the topography suggests that 
should saline spillover occur from C-111 canal, there would be a southwestward 
spread of the effects of this spill. This would be reflected most rapidly by the 
unicellular algae of the periphyton, then by salt-sensitive higher plants, and shortly 
thereafter by a disappearance of freshwater fishes and invertebrates. It is also 
concluded that although hurricanes such as Betsy of September 1965 occasionally push 
seawater onto the study area, the salt is rapidly flushed back into the sea by the 
accompanying heavy rains that normally accompany such storms, and effects other 
than by outright destruction by winds is transient. 
1967 0 
Taft, W. H. (1967) Modern carbonate sediments. Carbonate Rocks: Origin. Occurrence and 
Classification . G. V. Chilingar, H. J. Bissell, and R. W. Fairbridge (eds.) Developments in 
Sedimentology 9A. Elsevier, New York. 29-50. 
[DATE OF SAMPLING UNKNOWN OR NOT APPLICABLE.] Modern carbonate sediments are 
accumulating in almost all depositional environments except for the very deep oceans. 
Chemical and physical conditions, however, govern preservation and abundance of 
carbonate relative to non-carbonate material. Most modern marine carbonate sediments 
owe their origin to accumulation of bioclastic debris. Rarely can inorganic precipitation 
be actually proven. Mineralogical analysis of these sediments has shown that deep cold- 
water carbonates are predominantly low-magnesium calcites; whereas shallow, warm- 
water shelf deposits are composed predominantly of metastable carbonates (aragonite 
and high-magnesium calcite) with minor amounts of low-magnesium calcite. Significant 
quantities of supratidal dolomite has been reported in modern sediments. Diagenesis is 
taking place in modern sediments; however, only rarely can mineralogical or chemical 
changes be demonstrated in sediments that have not been exposed to freshwater. If 
modern shelf sediments are good examples of ancient sediments, almost all limestones 
have recrystallized. Florida Bay is one of the areas discussed. 
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