Yes would probably be more likely to happen when shreds were not hit by rain which would likely dissolve and flush out salts before they crystalized however if splitting was due to water and freeze thaw then cause would be wet shreds hit by hard freeze before they could dry so they would have been for a while above freeze line in wet times

Sent from my iPod

On Nov 10, 2010, at 7:29 PM, Benjamin Carter <[log in to unmask]> wrote:

> Susan and other Histarchers,
> 
> Could it be salt water getting into the sherd? When salt water dries, the formation of crystals can cause ceramics to spall/split.
> 
> Nearly all of my white earthen ware ceramics from a coastal Maine site (c. 1800) were split. I think it was due to a combination of freeze/thaw cycles and salt water. At this point most are from relatively close to the surface.
> 
> Ben Carter
> 
> On 11/10/2010 6:18 PM, Susan Walter wrote:
>> Hmmm, the site is in San Diego County...
>> 
>> ----- Original Message ----- From: "Mark Branstner" <[log in to unmask]>
>> To: <[log in to unmask]>
>> Sent: Wednesday, November 10, 2010 11:40 AM
>> Subject: Re: split ceramics
>> 
>> 
>>> Susan,
>>> 
>>> I don't know what part of the country that you're working in, but
>>> "frost spalling" is a relatively common phenomenon ...
>>> 
>>> Essentially, moisture gets into the porous fabric of the pottery and
>>> it splits the pottery when it freezes during the winter.  It
>>> certainly does not happen all the time, but it does occur with some
>>> regularity.  Sometimes just the glaze spalls off the fabric, but the
>>> fabric itself can split.
>>> 
>>> Mark
>>> 
>>> 
>>>> Nov. 10, 2010
>>>> 
>>>> Hello all,
>>>> 
>>>> I have a site with several sherds of transferware that are split so
>>>> that there is a transferware / glazed surface on one side and the
>>>> paste interior on the other side.
>>>> 
>>>> This makes them about 1/8 inch thick.  They tend to be about 1 inch
>>>> long, and about 3/4 inch wide.
>>>> 
>>>> The edges are not shaped; in "plan" view the pieces are
>>>> miscellaneously trapezoidal.
>>>> 
>>>> In appearance they somewhat remind me of porcelain pin
>>>> trays/childrens toy tea trays that are decorated and glazed on the
>>>> top and bisque on the bottom, except these transfer pieces are not
>>>> smoothly finished on the bottom ("bisque") like the porcelain items
>>>> are.
>>>> 
>>>> I do not think these were made intentionally.
>>>> 
>>>> I've not seen so many of these at one site before.  Has anyone
>>>> knowledge of what did this?
>>>> 
>>>> Thanks every one,
>>>> 
>>>> S. Walter
>>> 
>>> 
>>> -- 
>>> 
>>> Mark C. Branstner, RPA
>>> Historic Archaeologist
>>> 
>>> Illinois State Archaeological Survey
>>> Institute of Natural Resource Sustainability
>>> University of Illinois at Urbana-Champaign
>>> 209 Nuclear Physics Lab, MC-571
>>> 23 East Stadium Drive
>>> Champaign, IL 61820
>>> 
>>> Phone: 217.244.0892
>>> Fax: 217.244.7458
>>> Cell: 517.927.4556
>>> [log in to unmask]
>>> 
>>> 
>>> When you think of that perfect retort five minutes after the
>>> conversation is over -  that's when you're:
>>> 
>>> "... bursting with the belated eloquence of the inarticulate ..."
>>> 
>>> Edith Wharton in the "The Age of Innocence"
>> 
>> 
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