>On Fri, 22 Nov 1996, Glenn Morton wrote:
>
>David Tyler wrote:
>"I used to use this bentonite as evidence for correlation.
>However, a paper in _Geology_ (I think it was last year) provided
>geochemical evidence against the US / Europe link. I can't
>supply a reference now, but I'll look it up."
>GM replied:
>"I would be interested in any refutation of this connection that
>I missed."
>
>The reference is:
>Hayes, J.T., Melson, W.G., and Kunk, M.J. 1995, "Composition of
>biotite phenocrysts in Ordovician tephras cast doubt on the
>proposed trans-Atlantic correlation of the Millbrig K-bentonite
>(United States) and the Kinnekulle K-bentonite (Sweden)",
>Geology, 23(9), 847-850.
>
>The abstract commences: "Biotite phenocryst compositions in three
>thick, widespread Ordovician K-bentonites, the Deicke and
>Millbrig from Big Ridge, Alabama, and the Kinnekulle from Mossen,
>Vestergotland, Sweden, fall into three distinct groups, and so
>the proposed intercontinental correlation of the Millbrig and the
>Kinnekulle is suspect..."
After reading the article, I must agree that the Deicke and the Kinnekulle do
not appear to be correlative. This means that this bed cann not be used for
cross-continental correlation. The work does not affect the correlation of
the Deicke across the eastern US.
Thanks David for pointing this out to me. While one cannot keep up will
everything, one can certainly make a retraction, as I am doing, when others
point out the problem.
If I use the cross-atlantic correlation again by mistake, slap me up aside the
head again. :-)
glenn
Foundation,Fall and Flood
http://members.gnn.com/GRMorton/dmd.htm