40
Bastiaan Knoppers . Bjorn Kjerfve
Table 3.1. Geographical location of eight Brazilian coastal lagoon systems discussed in this study
Lagoon
State
Latitude (5)
Longitude (W)
Type
Cells
Araruama
Rio de Janeiro
22'53'5
42'15'W
choked
3
Jacone-5aquarema Rio de Janeiro
22'56'5
42'32'W
choked
4
Marica-Guarapina
Rio de Janeiro
22'56'5
4r46'W
choked
4
Piratininga-Itaipu
Rio de Janeiro
22'56'5
42'58'W
choked
2
Cananeia-Iguape
5ao Paulo
25'20'5
4T45'W
restricted 2
Concei<;ao
5anta Catarina
21'34'5
48'27'W
choked
3
Tramandai-lmbe
Rio Grande do 5ul
29'57'5
50'1O'W
choked
6
Patos-Mirim
Rio Grande do 5ul
30'55' - 32'30'5
50'55' - 5r20'W
choked
4
3.3
Coastal Lagoon Evolution
The evolution of the coastal plains of Brazil, including the formation and maintenance
of sand barriers and coastal lagoons, is well documented (Suguio et al. 1980; 1984; Martin et al. 1988; Martin and Dominguez 1994; Muehe 1984). The formation of coastal lagoons attained peak expansion during two major sea-level high stands in the Quaternary. The first, occurring approximately 123000 years B.P., corresponded to the last Pleistocene interglacial stage with a relative sea level at 8 ±2 m above the present level. The
second, occurring 5100 years B.P., corresponded to the Holocene sea-level high stand,
with sea levels m above the present (Martin et al. 1980; Suguio et al. 1980). Subsequently,
relative sea level fell but may also have experienced 2-3 m oscillations with a period of
200-300 years. These short term sea-level fluctuations would then have modified the
sand barriers and the coastal lagoons (Martin et al. 1980; Suguio et al. 1980).
Most expansive of the low-relief coastal plains of southeastern Brazil are the 100 km
wide coastal plains of Rio Grande do SuI, where the largest lagoons are found. The
Paraiba do SuI delta also represents Quaternary coastal deposits, where many coastal
lakes and lagoons are embedded within regressive beach ridge and sand terraces
formed by coastline progradation during sea-level fall and the continuous fluvial input of sediments (Dias and Silva 1984; Martin and Dominguez 1994). The narrow littoral fringe of the granitic coasts of Rio de Janeiro and Sao Paulo are bordered by
numerous lagoons. Most of these were formed during the Late Pleistocene and exhibit
a sequence of narrowly spaced Pleistocene and Holocene beach ridges (Muehe 1984;
Perrin 1984; Martin and Suguio 1989), including Araruama 1., the Saquarema 1. system, Marica-Guarapina L., Piratininga-Itaipu L., Jacarepagua-Marapendi L., and
Cananeia-Iguape 1. A string of small land-locked coastal lagoons is enclosed between
the Pleistocene and Holocene ridges between Araruama 1. and the shoreline (Fig. 3.3).
Examples of the evolution of Pleistocene and Holocene sand barrier sequences and
lagoons are schematized in Fig. 3.7.
The plains along the coast of Rio Grande do SuI are marked by four generations of
Quaternary marine sandy deposits, known as Barriers I, II, III, and IV. Barrier I is 10-
Bastiaan Knoppers . Bjorn Kjerfve
Table 3.1. Geographical location of eight Brazilian coastal lagoon systems discussed in this study
Lagoon
State
Latitude (5)
Longitude (W)
Type
Cells
Araruama
Rio de Janeiro
22'53'5
42'15'W
choked
3
Jacone-5aquarema Rio de Janeiro
22'56'5
42'32'W
choked
4
Marica-Guarapina
Rio de Janeiro
22'56'5
4r46'W
choked
4
Piratininga-Itaipu
Rio de Janeiro
22'56'5
42'58'W
choked
2
Cananeia-Iguape
5ao Paulo
25'20'5
4T45'W
restricted 2
Concei<;ao
5anta Catarina
21'34'5
48'27'W
choked
3
Tramandai-lmbe
Rio Grande do 5ul
29'57'5
50'1O'W
choked
6
Patos-Mirim
Rio Grande do 5ul
30'55' - 32'30'5
50'55' - 5r20'W
choked
4
3.3
Coastal Lagoon Evolution
The evolution of the coastal plains of Brazil, including the formation and maintenance
of sand barriers and coastal lagoons, is well documented (Suguio et al. 1980; 1984; Martin et al. 1988; Martin and Dominguez 1994; Muehe 1984). The formation of coastal lagoons attained peak expansion during two major sea-level high stands in the Quaternary. The first, occurring approximately 123000 years B.P., corresponded to the last Pleistocene interglacial stage with a relative sea level at 8 ±2 m above the present level. The
second, occurring 5100 years B.P., corresponded to the Holocene sea-level high stand,
with sea levels m above the present (Martin et al. 1980; Suguio et al. 1980). Subsequently,
relative sea level fell but may also have experienced 2-3 m oscillations with a period of
200-300 years. These short term sea-level fluctuations would then have modified the
sand barriers and the coastal lagoons (Martin et al. 1980; Suguio et al. 1980).
Most expansive of the low-relief coastal plains of southeastern Brazil are the 100 km
wide coastal plains of Rio Grande do SuI, where the largest lagoons are found. The
Paraiba do SuI delta also represents Quaternary coastal deposits, where many coastal
lakes and lagoons are embedded within regressive beach ridge and sand terraces
formed by coastline progradation during sea-level fall and the continuous fluvial input of sediments (Dias and Silva 1984; Martin and Dominguez 1994). The narrow littoral fringe of the granitic coasts of Rio de Janeiro and Sao Paulo are bordered by
numerous lagoons. Most of these were formed during the Late Pleistocene and exhibit
a sequence of narrowly spaced Pleistocene and Holocene beach ridges (Muehe 1984;
Perrin 1984; Martin and Suguio 1989), including Araruama 1., the Saquarema 1. system, Marica-Guarapina L., Piratininga-Itaipu L., Jacarepagua-Marapendi L., and
Cananeia-Iguape 1. A string of small land-locked coastal lagoons is enclosed between
the Pleistocene and Holocene ridges between Araruama 1. and the shoreline (Fig. 3.3).
Examples of the evolution of Pleistocene and Holocene sand barrier sequences and
lagoons are schematized in Fig. 3.7.
The plains along the coast of Rio Grande do SuI are marked by four generations of
Quaternary marine sandy deposits, known as Barriers I, II, III, and IV. Barrier I is 10-