Gerardo M.E. Perillo . M. Cintia Piccolo
10 r---,----,----r---.----,---,r---,---~
51-------------.6 mmyr- 1
-1.4 mm yr- 1
o /
:§: ...."
<:
o
.~
~
w -5 r----------------------------------r--~
-10 r------------------------------------+~
-15 L _ _ _ ~ _ _ ~ _ _ _ _ ~ _ _ _ L _ _ _ _ ~ _ _ _ L _ _ _ _ L _ _ _ ~
o
2000
4000
Years BP
6000
8000
Fig. 9.2. Sea level curve for the last 8000 yr for the Bahia Blanca Estuary. Data for each segment were
obtained from published literature only (modified from Gomez and Perillo 1995)
period (Fig. 9.2). In all cases the lowest level of occurrence and their minimum geological age were used. It included the estimation proposed by Lanfredi et al. (1988) that
in the last 90 years the sea level in the Argentina coast is rising to an average rate of
1.6 mm yr- 1 • Using this analysis, the delta sediments were covered by the sea becoming a shallow inner shelf zone for at least 4000 years.
9.3
Geomorphology
The Bahia Blanca Estuary (Fig. 9.1) is a mesotidal system considered by Perillo (1995)
as a coastal plain estuary formed by a series of NW -SE major tidal channels separated
by extensive tidal flats, patches of low salt marshes and islands. The area has an irregular triangular shape with the apex at the head of the estuary and its base in a NNESSW direction. The distance between Monte Hermoso Light and Punta Laberinto, considered the mouth of the area is 56 km.
A general description of the surficial morphology of the area was made by Esposito
(1986). He divided the region in three sectors: a) external; b) middle, and c) inner. The
external sector corresponds to the outer portion of the line running from about Punta
Tejada to Punta Laberinto and it is defined by high tidal flats separated from the sea by
sandy barriers. The inner portion is limited by the continent to the west and a imaginary line between Puerto Belgrano and the middle of Verde Peninsula. Extensive tidal
flats and some salt marshes are the dominant features. In between both portion is the
intermediate one that has large intertidal regions developed mainly parallel to the islands.
10 r---,----,----r---.----,---,r---,---~
51-------------.6 mmyr- 1
-1.4 mm yr- 1
o /
:§: ...."
<:
o
.~
~
w -5 r----------------------------------r--~
-10 r------------------------------------+~
-15 L _ _ _ ~ _ _ ~ _ _ _ _ ~ _ _ _ L _ _ _ _ ~ _ _ _ L _ _ _ _ L _ _ _ ~
o
2000
4000
Years BP
6000
8000
Fig. 9.2. Sea level curve for the last 8000 yr for the Bahia Blanca Estuary. Data for each segment were
obtained from published literature only (modified from Gomez and Perillo 1995)
period (Fig. 9.2). In all cases the lowest level of occurrence and their minimum geological age were used. It included the estimation proposed by Lanfredi et al. (1988) that
in the last 90 years the sea level in the Argentina coast is rising to an average rate of
1.6 mm yr- 1 • Using this analysis, the delta sediments were covered by the sea becoming a shallow inner shelf zone for at least 4000 years.
9.3
Geomorphology
The Bahia Blanca Estuary (Fig. 9.1) is a mesotidal system considered by Perillo (1995)
as a coastal plain estuary formed by a series of NW -SE major tidal channels separated
by extensive tidal flats, patches of low salt marshes and islands. The area has an irregular triangular shape with the apex at the head of the estuary and its base in a NNESSW direction. The distance between Monte Hermoso Light and Punta Laberinto, considered the mouth of the area is 56 km.
A general description of the surficial morphology of the area was made by Esposito
(1986). He divided the region in three sectors: a) external; b) middle, and c) inner. The
external sector corresponds to the outer portion of the line running from about Punta
Tejada to Punta Laberinto and it is defined by high tidal flats separated from the sea by
sandy barriers. The inner portion is limited by the continent to the west and a imaginary line between Puerto Belgrano and the middle of Verde Peninsula. Extensive tidal
flats and some salt marshes are the dominant features. In between both portion is the
intermediate one that has large intertidal regions developed mainly parallel to the islands.