First of all, both the varves and tree rings are used to calibrate carbon-14 so as such they are not independent confirmation of each other.
No -- first the varves and tree rings are matched up, one varve to one ring. Once we do that, then we measure the C14 in organic matter associated with, say, the 10,000th varve, and then measure the C14 with the 10,000th tree ring. No reason why both of these should give the same C14/C12 ratio -- yet they do. Each varve has the same C14/C12 ratio as its associated tree ring. The 12,000th varve gives the same C14 readings as the 12,000th tree ring.
A remarkable coincidence unless each varve and its associated tree ring were formed at the same time, and so incorporated the same ambient CO
2 with the same amount of C14.
And why would tree rings and lake varves match up one-to-one so precisely like this? Another amazing coincidence, unless each one really does represent annual events.
"The guilty one is not he who commits the sin, but the one who causes the darkness."
Clearly, he had his own strange way of judging things. I suspect that he acquired it from the Gospels. -- Victor Hugo