Biochemical Clues to Origin of Lime Mud

Lisa L. Robbins

A detailed biochemical analysis of proteins in major sediment producing algae, bottom sediment, and whiting sediment suggests whiting sediment is not wholly derived from the algae. Non-skeletal grains differ from skeletal components in that they lack an organic (proteinaceous) component, allowing use of proteins as a tracer to determine extent of algal contribution to the bottom sediment and to determine whether or nor this component can be observed in whitings.

Samples were decalcified, supernatent dialyzed, lyophilized, and analyzed using a reverse phase column on a High-Performance Liquid Chromatograph (HPLC). The algae Penicillus revealed a number of hydrophilic proteins that may be associated with the formation of aragonite needles. At least one of these proteins may be found in the bottom sediment HPLC profile. This suggests that Penicillus contributes at least partially to lime mud bottom sediments. The bottom sediment, however, demonstrated a complex HPLC protein profile, composed of many large molecular weight components. Whiting sediment, on the other hand, showed markedly fewer protein components than bottom sediment, although they contained two or three common non-algal proteins. The protein data suggest that whiting sediment may ot be stirred-up bottom sediment, as previously suggested, but may be produced within the water column.

AAPG Search and Discovery Article #91030©1988 AAPG Annual Convention, Houston, Texas, 20-23 March 1988.