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Florida Everglades and Restoration
Published in Caiyun Zhang, Multi-sensor System Applications in the Everglades Ecosystem, 2020
The biggest geological influence on the development of the Everglades is the Miami Limestone, which forms the floor of the lower Everglades. Miami Limestone is made up tiny egg-shaped concentric shells and calcium carbonate, called ooids. It has an extraordinary ability to store water and affects the hydrology, plants, and wildlife above it. The deposited limestone layer is known as the Biscayne Aquifer formed in the last glacial minimum around 110,000 years ago. Around the same time, the Atlantic Coastal Ridge (Figure 1.3(a)), a several mile-wide strip of limestone 20 feet higher than the current sea level, was deposited. This built the eastern edge of the Everglades. Meanwhile, along the western border of the Big Cypress Swamp, the Immokolee Ridge, also known as southwestern Pine Flatwoods, was formed as a slight rise with compressed sands. The rises in elevation along the eastern and western sides created a basin forcing water out of Lake Okeechobee to creep southward. When sea levels subsided, the Atlantic Coastal Ridge kept much of its water flowing south into Florida Bay though some flowed east into Biscayne Bay. Changes in these freshwater flows have changed both bays. The formation of the Everglades is a joint result of geology, climate, and geography. About 5000 years ago, south Florida’s climate took on its current subtropical and monsoonal character of dry winters followed by hot and moist summers with large amounts of rain (on average 50–60 inches per year), as seas surround it on three sides. The geographic location, along with the heavy precipitation in a wet season and the geological basin, the vast Everglades was formed from the water runoff of Lake Okeechobee. The ecosystems evolved with time, and the living habitats adapted to one another and to the nonliving environment. The stable warm weather, abundant fresh water, and sunlight in the past thousand years, consequently, led to a biologically productive Everglades ecosystem that abounded with fish and other aquatic animals. This in turn supported large number of reptiles, birds, and mammals.
Quantitative compaction trends of Miocene to Holocene carbonates off the west coast of Australia
Published in Australian Journal of Earth Sciences, 2021
E. Y. Lee, M. Kominz, L. Reuning, S. J. Gallagher, H. Takayanagi, T. Ishiwa, W. Knierzinger, M. Wagreich
The aragonite content (%) at Site U1461 was compared with porosity data, as shown in Figure 7b. Intervals of higher aragonite composition (>40%) were associated with mudstones and increases in porosity. The increase in aragonite concentration was well correlated with the increase in porosity (Figure 7c). An increase in aragonite content of about 10% corresponded to a porosity increase of about 3%. The trend is described as an exponential or a linear function, namely or respectively, where a is the aragonite content (%). Schmoker and Hester (1986) presented a similar correlation between porosity and aragonite content from upper Pleistocene grainstones of the Miami Limestone (Figure 7c).