I would like an experets opinion of this picture I have.  

The picture was purchased at a run of the mill garage sale.  The
framing and picture itself appear pre 19th century, and while I
realize that its incredibly unlikely, the picture itself reminds me of
those I've seen by John Walker Turner.
I have posted a number of photographs here...
http://www.windthrope.com/mm/
 
It is small horizontal picture that measures, 15 by 8.  The picture
itself appears to be pastel from its application - however it does not
seem to be as fragile as I would expect a pastel drawing to be.  When
I removed the backing there were seperate boards on either end that
were holding the drawing in the frame.  There were no markings on the
back of the picture, which I would describe as a thick and hard
cardboard type material.  I could find no signiture on the picture.
 
While I have not found many references to Turner using pastels, I
imagine he could have employed them at some point.   Did Turner ever
use pastels?  Are there an examples of these online?  Does this remind
you of a Tuner drawing or does it look like some other noted artist?  
Having seen the photo, do you believe its worth pursuing the true
attribution of this drawing - that is the possible value worth the
effort?

Thank you,
Michael