ironshore roatan

What is the Ironshore of Roatan?

Roatan is an island of many natural wonders. The world’s second largest barrier reef system extends just off the edges of the island’s beautiful white sand beaches while lush jungle forests and spectacular waterfalls act as a home to a number of native plant and animal species. One truly unique feature of this tropical wonderland is known as the Iron Shore. For those not familiar with the island and its physical features, the term may sound industrial or mechanical in nature, but the fact is that it’s a completely natural phenomenon. It’s actually quite spectacular in its own right. To help new visitors visualize this geological curiosity we’ve come up with an article to answer the question, “What is the Ironshore of Roatan?”

A Unique Topography

A simple description of the Ironshore is that it is apparently an ancient coral reef that subsided more than a million years ago, became fossilized then rose again from the depths of the sea. Ironshore belongs to a type of topography known as karst, which can be found in many places throughout the world ranging from Australia, Vietnam and China to Florida and Mexico’s Yucatan Peninsula. But Iron shore is that curious special case where Karst meets the sea.

Composition and Origins

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The Ironshore is composed of a prehistoric coral reefs that were deposited during times when the ocean levels were much higher or the underlying substrate lower than it is today. As the water levels receded, or the substrate was forced upward with the movement of tectonic plates, the fossilized reef became exposed to the air. Exposed limestone can be dissolved by rainwater, which is somewhat acidic, but many of the features that distinguish the Ironshore are caused by algae’s, fungi and other biological microorganisms. What results is a, pitted, brown or black rock, known as biokarst, which has a surface that looks similar to a cooled lava flow, but can be jagged and sharp to the touch. While karst fields that are carved solely by fresh water are typically flat, the biokarst of the Ironshore is shaped by a combination of rain, wind, and sea spray into pinnacles that can resemble miniature mountain ranges, coral reefs in the free air, or even growing plants.

Black and White

If you study the biokarst more closely you’ll find that although it is often black on the surface, it is grey to white in its interior. This is thought to be because the microorganisms only bore partially into the rock leaving the surface black. Because the interior of the limestone is left relatively untouched by the microbes, it remains a lighter color.

Embedded Fossils

As the biokarst of the Ironshore reaches further inland it transitions into a strip of lighter limestone that is less jagged in appearance. This reflects the lessoning of the wind component causing a different displacement of the eroding rainwater, and a different environment for different microorganisms. Both the inland transition karst and the Ironshore features fossilized yet recognizable coral species and shells embedded in the rock, giving intriguing glimpses into the life and times of those ancient seas.

Roatan’s Iron Shore

For those who enjoy experiencing unique land formations, Roatan’s Ironshore offers a glimpse into the past while allowing comparisons to similarities found in today’s coral reef systems. Ironshore can be found on the coast of many areas around Roatan, including West Bay and West End and surrounding areas by L’Alize. Enjoy this unique natural phenomenon during your travels to Roatan! (But bring your water shoes… and best not to fall onto it).

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