Marine Geology of the Tamiahua Lagoon, Veracruz, México

Abstract

The Tamiahua Lagoon is a brackish albufera located on the Gulf of Mexico coast, in the Coastal Plain of Veracruz State, between the Pánuco and Tuxpan rivers. Its most notable physiographic features are: a) the presence of several seasonal streams such as La Laja, Cucharas, Carbajal, Tancochín, Tampache, Milpas, San Lorenzo, etc.; b) within the lagoon, there are three large islands—Juana Ramírez, Del Toro, and Del Ídolo—which align approximately NW-SE, along with other smaller islands; c) a large sandy barrier (Cabo Rojo), which interrupts the dominant curvature of the Gulf of Mexico coast; d) channels connecting the Tamiahua Lagoon to the Pánuco River and the Tampamachoco Lagoon; and e) the Boca or Barra de Corazones. The climate is humid, with heavy rains in the summer and dry winters, except during storms with northerly winds; the winds that prevail in summer blow from the east, and in winter from the north and northeast; evaporation is moderate. The lagoon is shallow (2 to 3 m deep), with a slightly deeper channel located leeward of the sandy barrier, possibly due to the flow and reflux of tidal waters.
The Cabo Rojo barrier is made of quartzitic sand, with large active dunes in the northern portion that decrease towards the south, where they are small and practically stabilized. Two berm systems are observed, and in the leeward portion, there is local mangrove growth. The only current mouth, called Barra de Corazones, is small and narrow; there is evidence of three ancient mouths: one in the north, called Barra de Tampamachichi, and two in the south, the Galindo and Tanhuijo bars. Salinity is controlled by tidal action, precipitation, and river discharge. The water is predominantly brackish, although two facies were distinguished: an ultrahaline facies, greater than 30°/°°, and a polyhaline facies between 16 and 30°/°°. The first is restricted to the mouth and nearby areas directly affected by the waters that enter the lagoon due to tides, while the rest is polyhaline. The tides are small and not well known; for Tampico and Tuxpan, they are diurnal, and the flows are not well understood, but the lagoon is considered to be affected by them, due to river discharge and winds.