more on fossilization

Glenn Morton (grmorton@waymark.net)
Thu, 12 Feb 1998 21:08:39 -0600

For those who think that fossilization of biological details requires rapid
burial, here is some experimental evidence which discounts that. Shrimp
were fossilized with exquisite details in a lab, but it took 4-8 weeks.
This shows that it doesn't require rapid burial for fossilization to occur.

"In decay experiments modern shrimps became partially mineralized
in amorphous calcium phosphate, preserving cellular details of
muscle tissue, particularly in a system closed to oxygen. The
source for the formation of calcium phosphate was the shrimp
itself. Mineralization, which was accompanied by a drop in pH,
commenced within 2 weeks and increased in extent for at least 4
to 8 weeks. This mechanism halts the normal loss of detail of
soft-tissue morphology before fossilization. Similar closed
conditions would prevail where organisms are rapidly overgrown by
microbial mats."~Derek E. G. Briggs and Amanda J.
Kear,"Fossilization of Soft Tissue in the Laboratory,"Science,
259(1993):1439-1442, p. 1439

"The preservation of soft tissue by mineralization depends on a
critical balance between decay and precipitation. Some decay is
required to drive the process; too much leads to a loss of
information. Subcellular details of the most labile tissues can
only be replicated with a high degree of fidelity where
mineralization is rapid relative to decay (the rate depending on
a range of controls including concentration and oxidation state
of the mineral ions, size and type of organic substrate, and
pH)."~D. E. G. Briggs et al, "Phosphatization of soft-tissue in
Experiments and Fossils," Journal of the Geological Society,
London, 150(1993):1035-1038, p. 1035

glenn

Adam, Apes, and Anthropology: Finding the Soul of Fossil Man

and

Foundation, Fall and Flood
http://www.isource.net/~grmorton/dmd.htm