Beaches of the Gulf Coast

11. Beaches of Mexico and Cuba

11 Beaches of Mexico and Cuba O VERALL, the Gulf Coast of Mexico is relatively unpopulated and therefore rather pristine. Areas around population centers of Veracruz and Tampico are exceptions. This chapter considers some of the major places where people will visit. The discussion of the Mexican coast of the Gulf terminates in the Cancún vicinity. The Cuban shoreline is not well known and is frequented only by non-US citizens at this time.The northern coast just east of Havana is the most popular place to visit and has excellent beaches. There are two styles to the shoreline zone in Cuba, and each is discussed. Mexico The beaches are much the same in northern Mexico as they are in South Texas. The back-barrier lagoon here is also called Laguna Madre. Overall, the beaches of Mexico are fine sand and are terrigenous except for the area of Campeche Bay and the yucatán Peninsula, where carbonate skeletal debris dominates beach sediment. This material is coarser than that on the terrigenous beaches. In the area between the two distinct sediment types the beaches are dominated by a mixture of quartz and carbonate debris, giving the sediment a bimodal texture. Much of the information on Mexican beaches comes from the book Environmental Atlas of the Gulf of Mexico, in the chapters by Patricia MorenoCasasola and Arturo Carranza-Edwards et al. (see suggested reading at end of the chapter). 209 210 BeaChes alonG The GUlf of MexiCo CoasT Terrigenous Beaches The beaches in the State of Tamaulipas have their origin primarily in the deltaic sediments deposited at the mouth of the Rio Grande. This barrier island system is quite similar to that on the US side at South Padre Island except for the level of development. A narrow barrier island is separated from the mainland by Laguna Madre (figure 11.1). The beaches tend to be very wide, up to 250 m just south of the federal border. They slope gently toward the Gulf and are a combination of quartz and feldspathic sand with scattered shells and shell debris. Dune development is limited, and the beach is accretional . The width of the dry beach decreases toward the south, and the slope steepens until at Miramar, where the beach is less than 10 m wide with a steep foreshore. The beaches in the area of La Pesca north of Miramar have abundant shell material and are bimodal in texture because of it (figures 11.2 and 11.3).These steep beaches have eroding clay dunes on their landward side in La Pesca (figure 11.4). The clay in these dunes comes from fluvial sediment carried to the Gulf by the Soto Marina River. The State of Veracruz has a wide range of coastal types. In the northern part of the state the beaches are wide and sand dominated, similar to those in Tamaulipas (figure 11.5). Farther south the beaches have a distinctly different composition due to the Quaternary volcanic activity. Rocky sections dominate Figure 11.1. Oblique aerial view of the northern Tamaulipas coast with a narrow, pristine barrier fronting Laguna Madre. Photos in figures 11.1–11.16 courtesy J. W. Tunnell. 211 BeaChes of MexiCo and CUBa Figure 11.2. Beach surface showing a wide, gently sloping profile with a few scattered large pieces of limestone. Figure 11.3. Close-up of a typical shell concentration common on the northern Tamaulipas coast. Figure 11.4. Steep, narrow beach that extends to erosive clay dunes, La Pesca area, Tamaulipas. 212 BeaChes alonG The GUlf of MexiCo CoasT this coastal region (figure 11.6). As a result, both volcanic rock fragments and glass are common in the beach sediment. Boulder beaches are common and are generally somewhat narrow and steep with widths less than 50 m (figure 11.7). The beach sediment consists of boulders, some nearly a meter in diameter . This material is very coarse but tends to be well sorted (figure 11.8). These are unlike any other beaches on the Gulf. Figure 11.5. Fairly wide, sandy beach near the border of the States of Veracruz and Tabasco at SanchezMagallanes . . Figure 11.6. Bedrock shoreline reflecting the nature of the volcanic coast at Veracruz 213 BeaChes of MexiCo and CUBa In the State of Tabasco the beaches become more narrow with the maximum being...