I am working on the stable isotopic composition of some unaltered non-
luminescent Upper Maastrichtian worm tubes (e.g. Serpula collaria) from a thin
worm bed (a buildup and not a true reef) at the Eastern Desert of Egypt. I got
oxygen and carbon isotopic values that range between -5.1 and -6.4 PDB and
-2.5 and -4.6 PDB respectively. Do you think that these depleted isotopic
values can be related to; 1)a vital effect excerted by these worms or to 2)some
habitat-related controls or to 3)the effect of intense and widespread volcanism
which is documented by many previous workers and might injected 13C-depleted
volcanic CO2 into the atmosphere and surface seawater and hence expressed
in the isotopic signature of the worm tubes?. If you gonna use references
in your interpretation please cite it.
Thank you in advance for your prompt suggestions.