Hmmm, not very, when you look at the arguments put forward.Zbigniew Jarowoski has some very authentic criticisms of ice core reliability although I don't remember him querying the 'annual' bands as a means of dating.
In my search for reliable references for frozen vegetation in ice cores the ones available gave no source, and those in papers were behind a paywall, but there was one anecdotal statement about frozen Mammoths that brings up a new dimension to the catastrophe that caused their deep freeze. A refrigeration engineer said that an Elk, shot dead and left for five days in minus 20°F only froze for 6 inches from the outside, the core, from body heat, had started to rot.
His estimation, that for an animal the size of a mammoth to be frozen throughout the temperature would have to be in the minus 300°F region. And it seems that enough autopsies have been done on them to say they died of 'suffocation'.
Absence of air, temperature close to that of outer space, what could cause that? Something far larger than the mid air explosion of the1908 Tungusta event, but similar, as it seems sphericules of similar matter that peppered some of the mammoths were found below the 1908 event. All the air must have been blasted away for hundreds if not thousands of miles because if not the returning air would have been heated by compression and undone the freezing. It probably returned as a snow storm that changed the climate almost to the present.
The fact that both events occurred in Siberia seems a bit of a coincidence, perhaps the 1908 event was caused by a remnant of that enormous blast, on a multi-thousand year orbit.
