|
||||
Center for Coastal and Watershed Studies |
|
Caribbean Coast: Gulf of UrabáWithin the Gulf of Urabá (Fig. 2), rock outcrops along the coast are mainly basaltic lavas, agglomerates, and Tertiary sedimentary rocks. The Quaternary is represented by sandy-muddy alluvial deposits and sandy beach-ridge complexes located between cliff headlands (Ingeominas 1992). The Gulf of Urabá is a relatively wave protected environment with a general NS orientation and a maximum width of 20 km at its northern end (Fig. 2). At its northeastern part, the Gulf shores are typically characterized by narrow erosional beaches, backed by cliffs cut into sedimentary sequences of the Sinú Belt (Figs. 28 and 29). South of Necoclí, the Gulf of Urabá is dominated by deposition associated with recent human activities, the Turbo River delta being the most important (Figs. 30 and 31).
The east side of the Gulf of Urabá (Fig. 28) is defined by the prograding Atrato River delta, which has 16 active distributaries (Fig. 32) protruding into the 25-m-deep Gulf. The Atrato River is 730 km long and drains an area of about 36,000 km2 of the western Colombian Cordillera and the Serranía del Baudó, on the Pacific Coast. Rainfall in its drainage basin is 8 m/yr, which supplies a mean water discharge of 2700 m3/s and a sediment yield of about 11 x 106 ton/yr (Restrepo and Kjerfve 2000).
Northwest of the Gulf of Urabá and the Atrato River delta (Fig. 2), the Caribbean coast changes its character to a basaltic-cliff coast (Fig. 33) with wide alluvial valleys and beach-ridge shores (Fig. 34). Absence of sediments from the Atrato River permit the development of fringing coral reefs that become progressively more abundant toward Panamá (Díaz 2000).
|
AccessibilityFOIAPrivacyPolicies and Notices | |