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Cabo Pulmo National Marine Park attracts many visitors for several
reasons, it offers clear water and coral reefs below the surface
that provide outstanding scuba diving and snorkelling views. Kayakers
regularly arrive here and enjoy close sightings of the sea lion
colony nearby. Several resorts are in this area if you choose to
stay nearby and many watersport guides and tours are available.
This is a good spot for whale viewing in January through March.
Geological features
The outcropping rocks found in the area vary in age from the Mesozoic
to the Recent Era. The units are represented mainly by an intrusive
crystalline complex associated with metamorphic rocks that are probably
from the Triassic Period. Resting above this complex are clastic
rocks from the Comondú Formation of the Miocene and sandy-clayey
marine rocks from the Trinidad Formation of the Lower Pliocene.
There are alternate layers of sandstone, lutite, and limolite with
fossilbearing horizons from the mid-Pliocene, and a formation of
limestones and coquinas, deposited in ancient lagoons bordering
the coastal zone, as well as large, terrigenous deposits of alluvial
fans from the Pleistocene which covered the Salada Formation, filled
in the Santiago Basin, and currently are outcrops in the central
and northern parts of the Park.
The coral reef is approximately 20,000 years old. When we compare
its age to that of other coral reefs in the Americas, we find that
it is among the oldest in the American Pacific, since reefs in Panama,
for example, are barely 5,000-5,500 years old (Glynn and McIntyre,
1977). In the coastal portion of Cabo Pulmo Bay there is a marine
terrace from the Late Pleistocene (Kennedy, pers. comm., in Reyes
Bonilla, 1993a).
This area belongs to the Baja California Maritime Province and the
Southern Highlands Subprovince, according to a physiographic division
made by Edward O. Wilson. The Park’s zone of influence and
the Maritime- Terrestrial Federal Zone are constituted by coastal
plains that have developed in a stage of maturity modeled by fluvial
currents and eolic erosion. It has a limited diversity in terms
of geoforms. To the north we can observe a wide coastal alluvial
valley interrupted near Punta Cabo Pulmo [Cabo Pulmo Point] by a
granitic hill. Cabo Pulmo Bay and Los Frailes Bay also comprise
alluvial valleys composed of granitic and volcanic fragments. In
the former we find an area with dunes which rise to an approximate
height of 5 m and are 15 m wide. Cabo Frailes, which separates these
two bays, has a 100-m high hill. Part of the Maritime- Terrestrial
Federal Zone corresponding to the Park exhibits a series of marine
terraces from the Pleistocene which run parallel to the coastline
and are dissected by alluvial deposits. The ocean bottom does not
have much of a slope, and has a series of basalt bars. On three
of these bars there is a coralline community and a large number
of flora and fauna species. These bars extend offshore at a maximum
depth of 20 m in the north and a minimum depth of 2 or 3 m in the
central and southern zones, to the point that the upper part of
coral colonies is exposed during the low tide in some portions of
the bar closest to the coast.
Climate
The climate characterizing this region is very dry and hot, with
rainfall in the summer and precipitation in the winter amounting
to approximately 10% of the annual total. Precipitation is very
scarce throughout the year. The annual mean varies from 200 to 317
mm, increasing to as much as 700 mm when there are cyclones in the
months of July to November. Annual mean evaporation is 2,100 mm.
The annual mean temperature is 24ºC, and the maximum temperature
is 48.5ºC.
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