>How can one differentiate between modern and ancient pollen? My
>palynologist friend sets out 3 criteria for determining the contemporaneity
>of the pollen with the rock:
>1 The first criteria is color. As organic matter ages, it becomes darker.
>This is especially true as the rock is buried and the temperature rises. If
>the pollen is clear or very light yellow then they are modern introduced
>forms. Remember that the Hakatai shale has been buried by more than 7,000
>feet before the erosion began removing the sediment. At such a depth of
>burial the temperature would be approximately 190 deg F and the organic
>matter would turn brown.
This is correct and did in fact enter in to my conclusions.
>2. One must demonstrate that the Hakatai shale is not so thermally mature
>(cooked) that nothing organic could have survived. With all the volcanism,
>this rock is cooked. I looked up in the Lexicon of Geologic names of the
>United States, and found that the Hakatai contains diabase volcanic sills.
>This means that the lava intruded into the Hakatai.
This is not correct in the area sampled. Ther are plenty of intrusives in
the Hakatai, but they are generally localized and do not appear to affect
material any distance from the intrusives.
>3. The pollen grains should be flattened. My friend says that the pollen
>grains are compressed when buried in sedimentary rocks. This is especially
>true if the burial is as deep as the Hakatai was buried.
This is true. Most grains derived from rocks ("fossil grains") are pretty
>Allen has not chosen to discuss the pollen issue much since. He has
>suggested that you destroyed the pollen by using HF and that is why you
>didn't find any.
I pointed out that one of the pollen grains that Howe et al
>found had been treated with HF. Since then allen has been suggesting
>contacting the original authors about any questions. You are an original
>author in this field. Let me ask you if you saw any of burdick's pollen
HF treatment is one of the gentler things that is routinely done in
What was the color? Were they flattened. should they have been
They had the appearance of modern contamination.
Did HF destroy your pollen.