We began our day at the Cockburn Town fossil coral reef. This formation had remarkable preservation of the coral reefs present on San Salvador island approximately 120,000 years ago! By observing that all of these reef formations were preserved in their natural orientation within the rock record our class was able to determine that these fossil coral reefs were preserved without being greatly disturbed. While walking across this formation I observed a remarkably preserved brain coral specimen.
I found this particularly interesting because it allowed me to understand how the brain coral formed its structure. It is interesting to observe that the brain coral internal structure does not resemble its external structure. Dr. Elizabeth Griffith and I discussed how it would be possible to know the average growth rate of Brain coral to reconstruct the age of this specimen. Another interesting observation I had as we walked across the paleo coral reef was a pool of remarkably preserved staghorn corals.
This is a species of coral that is not typically observed growing around San Salvador island in present times so it was an incredible opportunity to study the morphology of this coral species in the field. At the end of our walk across the fossil coral reef, we came across a formation that represented a regressive stratigraphic sequence indicating a lowering of sea level. In this formation, we observed a transition from a coral reef with numerous coral species, to a nearshore shallow sandy-bottom environment, to a beach environment with shallowly dipping sand containing trace fossils.
-Contributed by Lucas
Photo credit: Lucas
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