I’m revising a few of my thoughts…
I still maintain that C-14 can’t be the beta emitter. Not enough energy to be detected by their Geiger counters.
Regarding K-40, I did some new math, and I now believe that if the Sverdlovsk lab only had Geiger counters for gamma measurements, then if all all the beta on the clothing was due to K-40, the lab would be incapable of measuring the associated gamma emission, so the only dose above background that they could report with statistical significance would be beta. Gamma would not be detected because their gamma detection capabilities are nowhere near as sensitive as their beta detection capabilities.
I don’t believe naturally occurring K in soil could accumulate and contaminate the clothing with enough K-40 to account for the amount in the report.
But if, say, the 1079 theory is correct, the bodies of the Ravine 4 were discovered, moved, and, let’s say, intentionally covered with a potassium rich chemical like potash or potassium chloride to melt the ice so they could be more easily identified, and then they were staged in the ravine to be rediscovered months later by Ivanov’s group, then I believe that would be consistent with the radiological report.