Tuesday, September 24, 2013

Quote: Robert Folk On Microbiota and Carbonate Petrology

JSR Paper Clips in a look back 20 years ago features an important paper by Robert Folk, carbonate sedimentologist par excellence, on SEM imaging of bacteria and nanobacteria in carbonate sediments and rocks.

..he says: “the minute interface between bacteria and carbonate petrology may be lilliputian in scale but are conceivably gargantuan in importance….”

Folk was probably moved in to making this utterance by a scene like the one below

These are layered dolomite strata of Triassic age from the Alps.  Folk argued that bacteria and nanobacteria have catalyzed the precipitation of such enormous thicknesses of carbonate minerals on the sea floor right through geologic history.

Many carbonate sedimentologists today do acknowledge that microbes play an important role in carbonate mineral precipitation but the details of the geomicrobiology i.e. exactly what physiological and chemical reactions enhance this precipitation is still being worked out. My recent post on this topic explores the role of microbes in dolomite formation.

It's not often you get to witness seminal breakthroughs in science. I now count myself lucky that I was present at the talk at the 1993 GSA meeting in Boston when Robert Folk described this hypothesis of bacterial influence on dolomite precipitation... 20 years on his argument is withstanding the test of time.

References: Folk, R. L., 1993b, Dolomite and dwarf bacteria (nannobacteria): Geological Society of America Abstracts with Programs, v. 25, p. A-397.


  1. Suvrat, cool post! Uncannily enough, I interact with Dr. Folk (or "Luigi" as he goes by these days) on a regular basis - he sits in the SEM lab next to our Stable Isotope Lab here from time to time! He is a very interesting person!

  2. Kaustubh.. wow! make the most of it :)