Re: walking on (post?) K/T eggshells

["David Marjanovic" <david.marjanovic@gmx.at>]

> http://www.vertpaleo.org/bulletin/181.pdf
>
> Scroll to page 61.

Thanks a lot, I didn't know this (must have overlooked it last time). Hm...
so all that chemical evidence is preserved in fossils but not in the
sediment itself? Sounds like it's a complicated fluvial deposit, like what I
cited, and no continuous horizontal layers are preserved. (_Six_ iridium
anomalies is certainly a bit much.) Unfortunately the bulletin doesn't say
whether the eggshells are vertically 50 m above the (chemical) boundary or
somewhere else in, say, a fluvial channel that's 50 m above it in that place
but cuts through it somewhere else. -- Okay, I'll wait for November instead
of continuing this type of distance diagnosis :-)
        Would be interesting when the chemical evidence is preserved in
_dinosaur_ eggshells. The eggshells must either have been produced after the
impact, the forest fires and the darkness, or the chemical stuff somehow
dissipated downwards through the sediment and accumulated in fossils that
were already in the ground. In the former case we have Lazarus dinosaurs,
regardless of whether the shells that occur 50 m above are reworked or not.
In the latter case I think the anomalies should be pretty low because they'd
be distributed over much more than the original centimeter-thin layer -- and
either not be detectable, or someone would write that they're particularly
low. Or they wanted to keep the report in the bulletin short and will tell
the world in November. Alternatives -- the eggshells are from turtles,
crocodiles and/or geckos which are supposed to occur on both sides of the
boundary.
        What confuses me is that "small mammals have not been recovered from
the [...] Paleocene strata". Ye, who is mentioned, reports to have found
mammals down to 2 m above the bottom of the Shanghu Fm... are they all big?
:-/