Everglades Pseudoatoll
Encyclopedia
The Everglades Pseudoatoll (also called a pseudo-atoll
) was a major geomorphic feature of southern Florida
during the Pliocene
epoch.
as a paleodepression
possibly created by an asteroid
impact upon the carbonate
Florida Platform
at the southern part of the Everglades National Park
. The pseudo-atoll is surrounded by a raised rim. Its growth as a reef
system and pseudo-atoll began during the Oligocene
reaching its maximum size of 330 km (205.1 mi) north to south during the Piacenzian
of the late Pliocene
. (Petuch, 163).
, not unlike South Pacific
atolls surrounded by a central lagoon. The west side was more developed than the east and south, as was the remainder of the west side.
On the western side of this pseudo-atoll lay the Immokalee Reef Tract and chain of islands called the Immokalee Archipelago. The large Hendry Platform lay behind the reef on the east. Mangrove
forests extended southwesterly of the pseudoatoll along what would be the southwestern Florida coast. To the northwest was the Myakka Lagoon System, a tropical estuary
of brackish water.
On the east the lay the Miami-Palm Beach Reef Tract with narrow back reef. Between the west and east was the wide and very deep 100 meter (330 feet) lagoon known as the Loxahatchee Trough. The northern part of the pseudo-atoll was the Kissimmee Embayment which was lined with mud flats and jungles of mangrove.
communities of shallow intertidal muddy-sand Mercenaria
tridacnoides Community of clam species, the deep lagoon Nodipecten peedeensis Community of scallop
s, the shallow lagoon Apicula buckinghamensis Community of tower shell snails
, and lagoon coral Phyllangia blakei Community.
The second time period is mid-Piacenzian and contains the shallow muddy intertidal Strombus
floridanus (conch) Communities, shallow lagoon tower shell snail Apicula gladeensis Community, lagoon scallop Nodipecten
floridensis Community, and the shallow lagoon Hyotissa meridionalis Community of foam oyster
s.
The third time period is the late Piacenzian and contained wave-action related coral zones of open ocean to sheltered basin. The communities are the high energy open ocean Pocillopora
crassoramosa Community of the coral reef crest. The back reef Dichocoenia tuberosa Community of coral, the low energy back reef Isophyllia desotonsis Community of coral, the sheltered back reef Stylophora
affinis Community, and sheltered reef lagoon Antillia bilobata Community of coral.
The fourth was during the maximum development of the Myakka Lagoon System estuary and included the mudflat mangrove forests of the Pyrazisinus scalinus Community, and the shallow and muddy lagoon clam beds of the Mulinia
sapotilla Community. Later the shallow lagoon mussel shoals of the Perna
conradiana Community and shallow lagoon Chama
emmonsii Community. The Kissimmee Embayment contained the shallow mangrove forests and mudflat Pyrazisinus kissimmeesis Community of sea snails and sand flats and turtle grass
of the Siphocypraea kissimmeesis Community.
Pseudo-atoll
A pseudo-atoll, like an atoll, is an island of coral that encircles a lagoon partially or completely. A pseudo-atoll differs from an atoll as established by several authorities.-Definitions:...
) was a major geomorphic feature of southern Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
during the Pliocene
Pliocene
The Pliocene Epoch is the period in the geologic timescale that extends from 5.332 million to 2.588 million years before present. It is the second and youngest epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch...
epoch.
Origin
The Everglades Pseudoatoll began its growth during the early EoceneEocene
The Eocene Epoch, lasting from about 56 to 34 million years ago , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Palaeocene Epoch to the beginning of the Oligocene Epoch. The start of the...
as a paleodepression
Depression (geology)
A depression in geology is a landform sunken or depressed below the surrounding area. Depressions may be formed by various mechanisms.Structural or tectonic related:...
possibly created by an asteroid
Asteroid
Asteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...
impact upon the carbonate
Carbonate
In chemistry, a carbonate is a salt of carbonic acid, characterized by the presence of the carbonate ion, . The name may also mean an ester of carbonic acid, an organic compound containing the carbonate group C2....
Florida Platform
Florida Platform
The Florida Platform is a flat geological feature with the emergent portion being the Florida peninsula.-Structure:The platform forms a rampart between the Gulf of Mexico and the Atlantic Ocean. The platform's western edge, or Florida Escarpment, is normally defined with water depths at 300 feet...
at the southern part of the Everglades National Park
Everglades National Park
Everglades National Park is a national park in the U.S. state of Florida that protects the southern 25 percent of the original Everglades. It is the largest subtropical wilderness in the United States, and is visited on average by one million people each year. It is the third-largest...
. The pseudo-atoll is surrounded by a raised rim. Its growth as a reef
Reef
In nautical terminology, a reef is a rock, sandbar, or other feature lying beneath the surface of the water ....
system and pseudo-atoll began during the Oligocene
Oligocene
The Oligocene is a geologic epoch of the Paleogene Period and extends from about 34 million to 23 million years before the present . As with other older geologic periods, the rock beds that define the period are well identified but the exact dates of the start and end of the period are slightly...
reaching its maximum size of 330 km (205.1 mi) north to south during the Piacenzian
Piacenzian
The Piacenzian is in the international geologic timescale the upper stage or latest age of the Pliocene. It spans the time between 3.6 ± 0.005 Ma and 2.588 ± 0.005 Ma...
of the late Pliocene
Pliocene
The Pliocene Epoch is the period in the geologic timescale that extends from 5.332 million to 2.588 million years before present. It is the second and youngest epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch...
. (Petuch, 163).
Description
The Everglades Pseudoatoll was a U-shaped asymmetrical system of reefs that surrounded the Okeechobean SeaOkeechobean Sea
The Okeechobean Sea was a Cenozoic eutropical subsea, which along with the Choctaw Sea, occupied the eastern Gulf of Mexico basin system bounding Florida.-Location:The Okeechobean Sea was a named for Lake Okeechobee of southern Early Oligocene Florida...
, not unlike South Pacific
Oceana
Oceana may refer to:* Oceana Keyboardist Derek Sherinian* 224 Oceana, an asteroid* Oceana , an indie rock/post-hardcore band* Oceana , aka Oceana Mahlmann, a German singer...
atolls surrounded by a central lagoon. The west side was more developed than the east and south, as was the remainder of the west side.
On the western side of this pseudo-atoll lay the Immokalee Reef Tract and chain of islands called the Immokalee Archipelago. The large Hendry Platform lay behind the reef on the east. Mangrove
Mangrove
Mangroves are various kinds of trees up to medium height and shrubs that grow in saline coastal sediment habitats in the tropics and subtropics – mainly between latitudes N and S...
forests extended southwesterly of the pseudoatoll along what would be the southwestern Florida coast. To the northwest was the Myakka Lagoon System, a tropical estuary
Estuary
An estuary is a partly enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea....
of brackish water.
On the east the lay the Miami-Palm Beach Reef Tract with narrow back reef. Between the west and east was the wide and very deep 100 meter (330 feet) lagoon known as the Loxahatchee Trough. The northern part of the pseudo-atoll was the Kissimmee Embayment which was lined with mud flats and jungles of mangrove.
Chronology
The pseudo-atoll's chronology is developed from deposition of a variety of community organisms. The oldest are the early PiacenzianPiacenzian
The Piacenzian is in the international geologic timescale the upper stage or latest age of the Pliocene. It spans the time between 3.6 ± 0.005 Ma and 2.588 ± 0.005 Ma...
communities of shallow intertidal muddy-sand Mercenaria
Mercenaria
Mercenaria is a genus of edible saltwater clams, marine bivalve molluscs in the family Veneridae, the Venus clams.The genus Mercenaria includes the quahogs, Mercenaria mercenaria, the northern quahog or hard clam, and M. campechiensis, the southern quahog...
tridacnoides Community of clam species, the deep lagoon Nodipecten peedeensis Community of scallop
Scallop
A scallop is a marine bivalve mollusk of the family Pectinidae. Scallops are a cosmopolitan family, found in all of the world's oceans. Many scallops are highly prized as a food source...
s, the shallow lagoon Apicula buckinghamensis Community of tower shell snails
Turritellidae
Turritellidae, the tower snails, is a taxonomic family of small to medium-sized sea snails, marine gastropod molluscs in the clade Sorbeoconcha.These snails are filter feeders...
, and lagoon coral Phyllangia blakei Community.
The second time period is mid-Piacenzian and contains the shallow muddy intertidal Strombus
Strombus
Strombus, common name the true conchs, is a genus of medium to large sea snails with an operculum, marine gastropod mollusks in the family Strombidae, the true conchs and their immediate relatives....
floridanus (conch) Communities, shallow lagoon tower shell snail Apicula gladeensis Community, lagoon scallop Nodipecten
Nodipecten
Nodipecten is a genus of large scallops, marine bivalve molluscs in the Pectinidae family. These scallops often have attractive, strongly colored, thick shells...
floridensis Community, and the shallow lagoon Hyotissa meridionalis Community of foam oyster
Oyster
The word oyster is used as a common name for a number of distinct groups of bivalve molluscs which live in marine or brackish habitats. The valves are highly calcified....
s.
The third time period is the late Piacenzian and contained wave-action related coral zones of open ocean to sheltered basin. The communities are the high energy open ocean Pocillopora
Pocillopora
Pocillopora, is a genus of coral in the phylum Cnidaria occurring in the Pacific and Indian Oceans. They are commonly called cauliflower corals and brush corals.-Description:...
crassoramosa Community of the coral reef crest. The back reef Dichocoenia tuberosa Community of coral, the low energy back reef Isophyllia desotonsis Community of coral, the sheltered back reef Stylophora
Stylophora
The stylophorans are an extinct, possibly polyphyletic group allied to the echinoderms, comprising the cornutes and mitrates. It is synonymous with the subphylum Calcichordata....
affinis Community, and sheltered reef lagoon Antillia bilobata Community of coral.
The fourth was during the maximum development of the Myakka Lagoon System estuary and included the mudflat mangrove forests of the Pyrazisinus scalinus Community, and the shallow and muddy lagoon clam beds of the Mulinia
Mulinia
Mulinia is a genus of bivalve mollusks or clams.-Species:* Mulinia cleryana* Mulinia coloradoensis - Colorado Delta clam* Mulinia edulis* Mulinia lateralis* Mulinia pallida...
sapotilla Community. Later the shallow lagoon mussel shoals of the Perna
Perna
Perna is a village in the administrative district of Gmina Nowe Ostrowy, within Kutno County, Łódź Voivodeship, in central Poland. It lies approximately north-west of Kutno and north of the regional capital Łódź.-References:...
conradiana Community and shallow lagoon Chama
Chama
-Places:*Chama, Colorado, USA, an unincorporated town*Chama, New Mexico, USA, a village*Chama, Zambia, a small town and district*Chama River , aka Río Chama, a river in Venezuela*Rio Chama , a tributary of the Rio Grande-Other:...
emmonsii Community. The Kissimmee Embayment contained the shallow mangrove forests and mudflat Pyrazisinus kissimmeesis Community of sea snails and sand flats and turtle grass
Thalassia
Thalassia may refer to:*Thalassia, Greece, a prefecture in Greece*Thalassia , a genus of seagrass commonly known as "turtle grass"*Thalassia , a queen of Characene...
of the Siphocypraea kissimmeesis Community.