Key-Stoned Species

Long ago in the Pleistocene era, the Keys were once indistinguishable from the flourishing coral reefs that have surrounded it in recent history. Over time the calcium carbonate skeletons from the dying reef fossilized into limestone, creating layers upon layers of fossilized shells and coral. This created a porous white to light grey limestone with very distinct and unique patterns. Through geological forces this reef gravesite slowly surfaced, creating the string of islands we now know today as the Florida Keys. The rock named 'Key Largo Limestone' is best seen in the geological state park of Windley Key. This old quarry used to be used to supply stone to complete railroad lines, until upon their completion people noticed that they could sell the unique looking material. 

While no longer in service, this quarry provides exceptional cross sections of fossilized coral and mollusks that lived during the ice age. While many different species of invertebrates can be found in the stone walls, the most common types located are brain corals, star corals, and porous corals. On this trip we were provided the opportunity to explore the wildlife, as well as the rich history of Windley Key State Park. It is such a cool experience to look at the old quarry sites and be able to identify things like mining techniques and how shallow the soil below the keys can be. 

The most interesting part of the park for me was being able to observe the things hidden inside the rock. For example, part of the rock wall was noticeably more orange than the rest and had a fine orange sediment falling out of it. This was because at the time of the corals being buried sand from the Saharan desert was being blown over, and the orange coloring was from the oxidation of the high iron content in the sediment. Evidence of ancient mollusks were left by pointed, spiral holes in the rock from where they were once buried if the shell itself was no longer there. There were numerous, almost perfect cross sections of brain corals preserved so well that the skeletal webbing in their holes were clearly visible when pointed at you, and as the coral reached its apex a fan pattern was revealed. It is important to note that this stone is not limited to the state park either. At the locations we have visited since I have been noticing the tell-tale patterning of brain corals in the stones and the fossilizes remains of mollusks in boulders.  This trip had provided me with such fascinating history about the area that I don't think its possible for me to observe the keys in the same way again.