Sure looks like it to me, dw.
I'm totally unfamiliar with ceramics with that light or white colored
paste. tho. All of ours around here is reddish orange to brown to
black. Heck there's a whole science called "Ceramic Petrology", where
they analyze the mixture of clay and tempering material of the clay,
or ceramic paste. Luckily you are in a good area to take it in to a local
university or museum to get it identified for sure.
But, for instance
, in the first pic, look at all the wavy grooves,
(not to be confused with groovy waves), on the interior of the cup.
And then right in the middle of those grooves, there's a gash that
looks like a fingernail imprint. Further down the rim, in that same pic,
there's a lip on the interior side.
I have seen pieces of clay like that where you can make out the
finger or thumbprint of the maker. These lines don't look like
a fingerprint, but then again, maybe. Most prehistoric pottery was
made with the 'coil' method, where they would roll the clay into
coils or rope-like sections, and build the pot up that way, smoothing
the coils together as they went. Alot of the time these type pieces
are the end of a coil that got into or close enough to the fire to
get 'fired'. The lines on the side of the piece in pic 2 kind-of look
like 'stretch' marks from this process.
And I could be way wrong here, but will be very interested to hear
what you find out.
Joe