Friday, 3 March 2017

Thin sections related to pyrotechnology in Bronze Age Sicily

The arrival of new thin sections is always exciting, but always daunting at the same time. Sediment micromorphology has to be one of the more challenging geoarchaeological techniques, simply because of the huge variety in the types of material you can encounter, and a deposit from one site never quite looks the same as one from another, even when they are related to similar activities. The samples from Case Bastione were collected to investigate formation processes and activities of a number of features in the Bronze Age settlement, including a large 'burnt' layer, and some strange pit deposits. The most striking thing about all the samples is the ubiquitous presence of these teeny tiny little creatures - my educated guess is that these are tiny foraminifera of some sort, present within limestone/chalk or another carbonate material (I need to do some research on Sicilian geology!). What is slightly confusing is the presence of a spherulite like appearance within the shells in cross polarised light. This isn't something I have seen before and I am not entirely sure what it means!


3 comments:

  1. I have many foraminifera in samples from coastal (tidal) deposits in the Netherlands. They look slightly different (like tiny ammonites). Yours could maybe also be shells from (young) snails?

    I also encounter the extinction cross in small mollusc shells. It does remind of spherulites - there it is formed because the crystallites are perpendicular to the surface of the object. WIth forams, however, I have always assumed it is formed when the crystallites are parallel to the surface of a round or bowl-shaped object. Different orientation, but similar effect.

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    Replies
    1. thank you! Is there anything published on this?

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  2. Not as far as I know. I am working on poblications for the coastal deposits, but won't go into detail on the optical properties of shells.

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