Belize is best described as a low lying shelf protected by an 180 mile long coral barrier reef. Much of the southern half of the country has been up lifted over 3000 feet, forming the Maya Mountains. Draped off the north and south flanks of the Maya Mountains lie rugged limestone territory, while further north the topography is dominated by flat limestone beds dotted with mounds of eroded soils. Most of these coastal and northern soils are derived from the erosion of the Maya Mountains.

Rio Bravo Escarpment

New River Lagoon

The Maya Mountains consist mostly of dense and very old granite, quartz and shales. Some 60,000,000 years ago, the entire upland area was covered by sea and several hundred feet of limestone were deposited by the shells of billions of primeval crustaceans. As sea levels dropped, this mantle of limestone began to erode and streams cut deeply into the granite and shales. This continual process of erosion has formed the shape and lay of the land in Belize today. Geologist have pieced together a theory of how the topography of Belize today was formed.

The figure above is adapted from the classic book "Land Use in British Honduras" by Charles Wright. Wright theorizes in Fig. A how Belize might have looked 60 million years ago when the seas covered much of the Maya Mountains. As the sea level dropped, erosion of the limestone blanket and underlying granite, shale and quartz rock carried tons of soil mainly to the north, depositing the debris over what is today northern Belize. Fig. B above shows the shoreline at a later stage, when the main river channels where to the north and east. Fig. C shows the shoreline approaching what we see today, with coastal plains forming to the south and east. As the sea-level dropped further, the flat limestone beds of the north uncovered and isolated islands of erosion deposits formed. Fig. D shows Belize as we see it today.

In simple terms, Northern Belize is dominated to the west by a series of escarpments, cut by rivers which once originated from the ancient uplands of the Maya Mountains. East of these escarpments lie flat ancient limestone which gently sloped down into the Caribbean Sea and the Belize Barrier Reef.

A cross-section of Northern Belize using the A - B transect shown at right and displayed below, plainly shows the three escarpments (Rio Bravo, Booth's, New River), the river valleys, the mounds of eroded sediments and the coastal lagoons. This pattern of landform, geology and soils determines to a large extent the type of vegetation located in a particular region.