Tuesday, May 1, 2012

The Unlikely Taphonomy of an Atlantic City Seahorse




Having grown up on the South Jersey Shore (Atlantic City in particular) and living barely one-tenth of a mile from the ocean, my wife has strolled the beach at least a million times, for how many years I’m not allowed to say, in every season and in every type of weather. The typical marine debris that one finds washed up on the beach includes a myriad of bivalves usually disarticulated or pulverized by the high-energy wave system, pungent seaweed torn up from the depths of the seafloor, ominous clear blobs of jellyfish, and horseshoe crabs by the truck load. My wife says that over the decades the beach fauna has changed dramatically. When she was a little girl, she recalls scooping up handfuls of wet sand and finding armies of tiny sand crabs scurrying for cover.

Last week she stumbled on a most unique find, something she’d never seen before or others for that matter. A seahorse perfectly preserved. As my wife described it, the seahorse was washed ashore after a storm with typically high winds and breaking waves. Tempests that hit the shore leave the beach in unpredictable states: sometimes robbing it of sand, and at other times, depositing large quantities of it. Sometimes there’s a plentitude of marine debris; other times none. Sedimentary budget. Offshore bathymetry. Zonation. Barrier beach dynamics. Too much geology for her! 

According to her, this particular storm left the beach flat and smooth, uniquely devoid of marine erratic with that one tiny exception. The seahorse, according to her description, was buried beneath the thinnest possible veneer of sand that had blown over it and captured the Neptunian creature in a near perfect and most ephemeral state. Very excited, my wife immortalized the find with her blurry, low mega-pixel, flip-phone camera and texted the image to me.

Fossil in the making? Not likely. A highly untaphonomous environment to say the least. Sea gull scavenging and microbial decomposition will ravage the remains. Rapid anoxic burial? Too late for that. Diagenetic alteration and pyritization? Not on this beach. No transgressing seas and unfavorable sedimentary geochemistries. Best just to marvel at the find. It will be gone tonight with the next tide.


4 comments:

  1. That's a really kool find. My former neighbour who I visited last year in San Diego CA was an avid Baja explorer before all the #@/% hit the fan with all manner of Drug Cartel Border killings. He showed me a very large fossil Nautilus he found down there. This thing was huge. Unfortunately and understandably all the legs were gone, but the entire huge shell and the numerous several inch long tentacle stumps were still intact.

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  2. Awsome. I keep my own geoblog (written in spanish) so I fully appreciate the time and effort behind this excelent post. I can't wait to read part II. Congratulations!

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    1. Thanks so much for your comment of appreciation and for visiting "Written in Stone"! Jack

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