>Hello!
>I am wondering if anyone has information about how to figure out the age of a conch shell. I know carbon dating is one way but I know the shells couldn't be hundreds of years old. Any information or articles would be appreciated!<

Unfortunately, the fancy methods carry fancy price tags.

Carbon dating would be relevant for figuring out the absolute age (i.e., how long ago was this alive) but not for figuring out the lifespan of the individual.  The younger the material, the more precise the carbon date can be, but it still has a significant error bar (by everyday standards).  However, atmospheric nuclear bomb tests conveniently produced a sudden spike in the amount of carbon 14 and other radioactive isotopes.  Thus, a shell (or other organism) that was alive during the time of active atmospheric bomb testing will have a relatively high level of 14C.  Shells from after the test ban treaty will have lower 14C than those living during the testing, but still have significantly higher than pre-nuclear shells.

If you have some local source of shells (or other carbonate producer, such as coral) of known date, you could compare stable isotopic ratios in the shells to the ratios at known dates.  These ratios are sensitive to a wide variety of environmental factors and thus vary over time.  If you find a shell that shows the same pattern over time as your known data(determined by sampling the shell along the direction of growth), then you have a likely date of origin.


If you are dealing with shells from a precisely known location, you may be able to find associated datable artifacts, since most piles of conch shells I have seen are produced by fishermen.  Finding a shell on top of a Coke can, for example, would give a maximum age.  This is much cheaper than isotopic analysis.

    Dr. David Campbell
    Old Seashells
    University of Alabama
    Biodiversity & Systematics
    Dept. Biological Sciences
    Box 870345
    Tuscaloosa, AL  35487 USA
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That is Uncle Joe, taken in the masonic regalia of a Grand Exalted Periwinkle of the Mystic Order of Whelks-P.G. Wodehouse, Romance at Droitgate Spa