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International Journal of Marine Science 2014, Vol.4, No.37, 1-12
http://ijms.biopublisher.ca
4
3 Physical, geographic and ecological aspects
3.1 Geology
The area is composed of marsh deposits; terrigenous
carbonate and peat of mangrove, belonging to the
Holocene (Iturralde-Vinent, 1989). Iturralde-Vinent et
al. (1981) suggest that Playa Florida consists of a thin
layer of shelly sand, mainly from mollusks, which
ranges from 1-2 mm wide and lies on peat clays.
Along the whole coast, flooded river channels are
observed in large measure inactive, representing a
coastal delta plain. These deltaic-marine sediments are
of late Pleistocene to Holocene, and lie on the Rincón
Hondo formation.
Cabrera and Peñalver (2001) consider that in marine
platform there is a complex of bars, probably formed
during the maximum of the Flandrian transgression
that, in exceptional, cases has been considered as a
unit named Los Pinos formation due to its size, its
degree of lithification and its clear definition of their
morphological features. This formation is represented
by oolitic calcarenites and biocalcarenites of medium
grain, well-rounded and well-selected, sometimes
inclined lamination. Its color is white and cream,
sometimes covered by sands that are the result of its
own disintegration under the influence of weathering
processes. Also, it is covered in part by peat deposits
and current arenas.
At a distance 2-3 km of the shoreline, landward, are
Pleistocene deposits belonging to the Guevara
Formation, which is composed of plastic clays
(montmorillonite and kaolinite-montmorillonit), fine
gravel, sand, ferric coverage fragments (hardpan) and
stones. The composition is oligométric predominantly
of siliceous rocks. These deposits are transported by
rivers of the area, contributing with large amounts of
sediment to the coastal zone.
The neotectonic coverage has a domain of
neoplatform epicontinental of late carbonate deposits
(Iturralde-Vinent, 1989). The average amplitude of the
neotectonic movements of P
2
3
-Q is 0 to -500 m
(Orbera, 1989).
According Tristá(2003), the composition of sediments
of the beach are terrigenous; fine and medium sands,
well sorted with abundant quartz content and some
other minerals of zircon group. In addition, the grains
show a strong activity on stones, with a marked
roundness.
3.2 Geomorphology
The relief is a fluvial and fluvial-marine plain,
deltaic-marine often marshy, belonging to the
Quaternary (Alfonso, 1989). Landforms of the area
are developed in congenital structures (N
2
-Q), created
by light plains neotectonic movements (up to 180m)
of periphery blocks of large horstic areas of plains
(Magaz, 1989). The height above mean sea level does
not reach 2m, in the sandy bar where the community
sits. The coastal relief of the study area is
characterized by gentle slopes and shallow depth of
their bottoms. Approximately 500 m from the coast is
the isobathymetric line of 2 m of depth (Nautical
Sheet 11539).
The area is composed of brackish lagoons, freshwater
lagoons, estuaries and seasonally flooded savannas.
However, the relief is continually changing due to the
natural sinking of the area resulting from natural
geological movements.
3.3 Climate
The climate of the region classify as typical of inland
plains with a wet season, high evaporation and high
air temperature (Días, 1989) and their characteristics
are shown in Table 1. The predominant wind direction
is from the Northeast (August - March), while in the
remaining four months are from the east-northeast
(April-July).
Table 1 Climatic characteristics of the area of Playa Florida.
Parameter
Value
Annual mean rainfall
1 200 mm
Annual mean rainfall in wet season
1 032 mm
Mean rainy days
80 days
Annual mean evaporation
2 200 mm
Mean air temperature:
Annual
January
July
27
℃
25
℃
29
℃
Wind velocity
6 – 10 km/h
3.4 Hydrology
3.4.1 Hydrography
Playa Florida village is located in the lowest part of
the river basin Mala Fama. During the rainy season,
some areas are flooded by the spilling of the river.