Talk:Tonstein

"Dubious" template

I tagged one sentence in the article as "dubious". My specific concern is with the part that says "younger kaolin claystones are generally softer, white, and plastic." It is true that most kaolin deposits are soft, but degree of induration is not related to age. Rather, I believe that soft kaolin deposits formed by entirely different mechanisms. I don't have good access to the source cited for this factoid in order to check what it actually says. Can someone else please help? --Orlady (talk) 00:14, 28 December 2012 (UTC)

You can see the full text on page 337 here (or at least I can), which shows that the text in the article is a precise quote from the book, but lacks the context to make it understandable. The younger kaolinite claystones referred to are the Oligocene ball clays at Bovey Tracey (these are white and plastic), which formed by erosion of nearby weathered granite, so not tonsteins. I've reworded it both to clarify the meaning and to avoid the copyvio. There's still a question in my mind as to whether we need to include it at all, although I'm leaning on keeping it. Mikenorton (talk) 08:55, 28 December 2012 (UTC)

Thanks. I only have "snippet" view of that book, and the only thing I could see on that page was a snippet from the table. Now that I know to search on "Bovey Tracey", I can see the 8 lines from that page that include the statement in question. I also see a snippet from page 33 that tells about the geologic conditions under which kaolin deposits occur.

IMO, in the context of this article, the information about the ball clays at Bovey Tracey is little more than irrelevant trivia, as the geology of the ball clays is completely unrelated to the geology of tonstein. The facts about the Bovey Tracey ball clays would have some relevance in the article on kaolinite, though. --Orlady (talk) 22:02, 28 December 2012 (UTC)

PS - I discovered that I can see all of page 337 if I enter it as a U.S. URL: http://books.google.com/books?id=k3PnTbjR0DMC&pg=PA337 . Also, now I now that the table in my previous snippet view is on page 339, not page 337. --Orlady (talk) 22:10, 28 December 2012 (UTC)