Thanks for the references.
> The first two were published in Japan, and you can be excused for not
> having seen these. The last was not. I think the problem died down,
> because everyone was pretty much convinced by what happened at Spirit Lake
> that the case was closed on YNP. If Fritz subsequently changed his mind (I
> suspect that he has not), it is news to me.
Yes, everyone is convinced. Have you read
CROSS-IDENTIFICATION OF RING SIGNATURES IN EOCENE TREES (SEQUOIA-MAGNIFICA)
FROM THE SPECIMEN RIDGE LOCALITY OF THE YELLOWSTONE FOSSIL FORESTS
AMMONS R, FRITZ WJ, AMMONS RB, AMMONS A
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
60: (1-2) 97-108 JUL 1987
Here's the abstract:
We have found a characteristic ring signature in Eocene trees (Sequoia
magnifica) from the 15-25m interval of the Specimen Ridge section of the
Lamar River Formation in Yellowstone National Park U.S.A. This signature
indicates that these stumps were contemporaries growing in the same forest.
This interpretation supports the theory that trees on the Specimen Ridge
section were preserved where they grew in low energy valley facies far
from the volcanic source peaks that produced the volcanic sediment.
And from the first page:
"All workers agree that most of the layers of petrified trees on Specimen
Ridge, an area representing deposition in lower-energy lowland facies, are
most likely preserved in place"
and quotes himself, Dorf, Yuretich, and more.
I don't know whether Fritz has changed his mind or not, since I don't
know what he used to think, but it seems clear what he thought more than
10 years ago. Had you not read this paper, or the 1984 exchange in
_Geology_?
They found a 60-year signature pattern that they found in the 15-25m level,
but they only tested it on like three trees (which were clearly buried
in situ). They also tried it on some others that weren't obviously in
situ buried, but didn't find a match. They said the samples were poor,
though, so that this is more open for further study.
> >Since then, there has been other dendrochronology done on that forest, it
> >looks like, but nothing else that I found.
>
> Arct presented his stuff at GSA and at other meetings, but the data in his
> thesis have never been published formally. Nevertheless, these data remain
> the most compelling evidence for the allochthonous origin of the trees.
> His thesis is referenced in the Chadwick and Yamamoto paper.
The Ammons and Fritz reference Arct's thesis, as well as your paper. Their
signature, from what Glenn said, is a lot better than Arct's. They predict
that matching signatures can be found on not-very-separated intervals (what
Arct did) due to the erosion and whatnot, but not on widely-separated
intervals in the ridge. It seems no-one has taken up that challenge,
as there is only one cite of this article, and that is by a good article
by Collinson:
PLANT EVOLUTION AND ECOLOGY DURING THE EARLY CAINOZOIC DIVERSIFICATION
by COLLINSON ME
ADVANCES IN BOTANICAL RESEARCH
17: 1-98 1990
Here's an excerpt from where she discusses Specimen Ridge:
From _Plant Evolution and Ecology During the Early Cainozoic Diversification_
by Margaret Collinson, Advances in Botanical Research 17 (1990) p.1-98.
Collinson discusses the Yellowstone Specimen Ridge site on p.56-58 as
during a discussion of community reconstructions of ecology in the Eocene
as follows:
The petrified forests of Yellowstone National Park, USA, have long been
regarded as examples of Eocene forests preserved in situ (Dorf, 1964).
Numerous levels containing upright tree stumps can be observed in an
exposure at Specimen Ridge. However, following the recent eruption of
Mount Saint Helens many observations were made concerning tree stump and
trunk depsition in comparable modern volcanogenic sediments (e.g. Fritz,
1980; Fritz, 1983; Fritz and Harrison, 1985). These showed that upright
tree stumps could be transported and re-deposited so as to appear as if
they had been buried in situ. A palaeoecological analysis of the woods and
pollen from the sediments at Yellowstone (Chadwick and Yamamote, 1984)
emphasized earlier observations of "mixed" floras in single levels. Growth
ring evidence and leaf and pollen floras all implied that mixtures of
tropical and temperate plants existed at individual stratigraphic horizons
(see also Fritz, 1981). These factors seemed to support suggestions that
the "fossil forests" were not perserved in situ. Retallack (1981) and
Yuretich (1984) responded to these observations by demonstrating that some
stumps were unquestionably in place as shown by fine roots embedded in
fine grained sediments below conglomerates which flowed around the trunk
bases. Furthermore, well-differentiated soil profiles were developed at
these horizons. One example of these data and associated stratigraphy is
given in Fig. 41 [reproduced from Retallack (1981)]. Other tree logs were
clearly horizontal and obviously had been transported (Fig. 41). Ammons
et al. (1987) have provided further support for the in situ nature of some
stumps by documenting cross identification of growth ring signatures at
some levels. Karowe and Jefferson (1987) have documented incipient
silification in trees buried in situ on Mount Saint Helens. Present evidence
suggests therefore that the Yellowstone forests are much more complex than
previously thought. They seem to include trees buried in situ and
others probably transported from elsewhere (for further discussion see Wing,
1987). They represent an excellent resource for future study combining
multidisciplinary approaches in order to reconstruct the ancient forest
communities.
References:
Dorf, E. (1964) Sci. Am. 210, 107-114.
Fritz, W. J. (1980). Geology 8, 309-313.
Fritz, W. J. (1981). Geology 9, 53-54.
Fritz, W. J. (1983). Geology 11, 733-734.
Fritz, W. J. and Harrison, S. (1985). Sed. Geol. 42, 49-64.
Chadwick, A. and Yamamoto, T. (1984). Palaeogeogr. Palaeoclimatol.
Palaeoecol. 45, 39-48.
Retallack, G. J. (1981). Geology 9, 52-53.
Yuretich, R. F. (1984). Geology 12, 159-162.
Ammons, R., Fritz, W.J., Ammons, R.B. and Ammons, A. (1987). Palaeogeogr.
Palaeoclimatol. Palaeoecol. 60, 97-108.
Karowe, A.L. and Jefferson, T.H. (1987). Geol. Mag. 124, 191-204.
Wing, S.L. (1987). Ann. Missouri Bot. Gard. 74, 748-784.
The consensus by people involved seems to be that while most of the
levels represent in situ-buried trees which grew contemporaneously
and form "fossilized forests," there is also transported material present
as well, which I'm not sure anyone has figured out where it came from.
-Greg