He only discussed radium, and discounted this as a major effect based on low concentrations of radium in coal (and yet my own brief stint of research has turned up many abstracts showing that concentrations of radionuclides vary widely in coal - some of these are pre-1989 so I don't know why Lowe didn't address this more carefully). on the Fundamental Aspects of Modern Physics, 2000, Luderitz, Namibia.
(3) bacteria/fungi hypothesis: Lowe then makes a reasonable case for fungi and bacteria - there are fungi that can degrade lignite (Polyporus versicolor and Poria montiola), as well as autotrophic "thiobacillus-like" bacteria that oxidize pyrites in coal, and he points out that bacteria have been found 3km underground apparently living on granite. Published by World Scientific Publishing Company in 2001.
So, it looks like in-situ production of new C is the best-supported hypothesis; but research is ongoing, and I look forward to seeing the results of the Old Carbon Project and new research on the deep subterranean bacteria. Recent references from the ongoing "Old Carbon Project": "The measurement of very old Radiocarbon ages by AMS." 2001.
References A great general introduction to carbon-14 dating: General information on the many types of neutrino detectors: stanford.edu/gen/meeting/ssi/1997/wojcicki4A very nice in-depth discussion of the three new neutrino detectors and how they work (scroll almost to the end to read about Borexino): diagram of the Borexino (Italy) neutrino detector - notice the enormous shielding to protect it from radiation from the surrounding rock: about the Borexino detector from Princeton University: original paper which raised this "old coal" issue: "Problems associated with the use of coal as a source of C-free background material." D.
The Problem: Accelerator mass spectrometry (AMS), a sensitive radiometric dating technique, is in some cases finding trace amounts of radioactive carbon-14 in coal deposits, amounts that seem to indicate an age of around 40,000 years.
Though this result is still too old to fit into any young-earth creationist chronology, it would also seem to represent a problem for the established geologic timescale, as conventional thought holds that coal deposits were largely if not entirely formed during the Carboniferous period approximately 300 million years ago.
Scintillation fluid is made from fossil fuels such as methane or oil (plus some other ingredients), and it sparkles when struck by beta particles or certain other events such as neutrinos. However, if there are any native beta emitters in the fluid itself, that natural radioactive decay will also produce scintillant flashes.
The Borexino detector, and other planned detectors of this type, must keep native beta emissions to below 1 count per ton of fluid per week to reliably detect solar neutrinos. A new species of bacteria found in deep, hot fossil fuels: "Isolation and characterization of Thermococcus sibiricus sp. from a Western Siberia high-temperature oil reservoir." 2001. These results demonstrate that hydrogen-based methanogenic communities do occur in Earth's subsurface, providing an analogue for possible subsurface microbial ecosystems on other planets. I use scintillant every day in my own work to detect H-tagged hormones. But I only use a milliliter at a time - the concept of 800 tons really boggles the mind! So, the physics community has gotten interested in finding out whether and why fossil fuels have native radioactivity.