ABSTRACT

Although the destructive capacity of coastal storms is well known, major storms may also maintain coastlines. In some instances, storms may be the principle agent of construction. This capability of storms can be demonstrated along the coast of northern British Honduras, which is located on the southern edge of the Caribbean storm track and is struck by periodic hurricanes and lesser storms.

The coastline of British Honduras is a complex of lagoons, mangrove marshes, and barrier ridges. Tidal deltas grow into the lagoons and form extensive, low mudflats along the rear edge of the barriers. Other sedimentary processes are: 1) filling of the lagoon with mud and shell debris, 2) encroachment by mangrove marshes, and 3) gradual elevation of supratidal mudflats. Together, these processes represent "normal" conditions.

Many abandoned tidal deltas occur along the barriers. In these deltas, the seaward month of the tidal channel is blocked by barrier ridges. Thus, the construction of barrier ridges represents an additional process which, at least locally, is able to upset the balance of forces responsible for the construction of tidal deltas. Major storms can be shown to be the cause.

Scattered, newly formed beaches composed of soft, black, H₂S-rich mud occur in small bights along the coast. At Northern River Lagoon, the sequence, from top to bottom, of black mud (24 in), flotsam (4 in), and clean, quartz sand (at least 4 ft) indicates that the beaches did not accrete slowly, but formed during a single event. At Midwinter Lagoon, a well developed tidal channel that was open in 1944 is now blocked by a beach composed of black mud, with ridge-and-swale topography. This beach was deposited by Hurricane Hattie in 1961. If colonized by mangrove, the beach probably will become a permanent addition to the barrier ridges.

The development of the British Honduras coast can be understood only by considering both continuous and episodic events. An understanding of the complex interplay of all agents is necessary to evaluate the events that have occurred.