However, Davidson and Wolgemuth (D&W) also claimed that varves within a Japanese lake prove that the earth is at least 50,000 years old.
Varves are repetitive groups of laminations within sediments that are assumed to represent successive annual deposits.
D&W argued that since the yellow dots fell on a nearly straight line, this proved the radiocarbon ages were true calendar ages, at least for the last 50,000 years or so.
If this were really true, it would indeed be a strong argument for an old earth.
The Varves Working Group was active under the PAGES umbrella from 2009 to 2015.
Before the Varves Working Group was formed in 2009, it had been around 10 years since the last specific meeting of the "varve community" at the Lammi Biological station in Finland in 1999.
This is important, because volcanic ash and dust are rich in silica, the main ingredient diatoms use when constructing their skeletons. Scientists radiocarbon-dated leaf, branch, and insect fossils within the Lake Suigetsu sediments.
Therefore, the Ice Age provides the opportunity for thousands of non-annual diatom blooms to occur in a few centuries, plausibly explaining the white diatom layers observed in the Lake Suigetsu sediments. D&W converted these radiocarbon ages into what they called “measured carbon-14” and then plotted those values against tree ring and varve calendar ages in their Figure 7 (our Figure 2).
Radiocarbon Ages Don’t Equal Varve Ages The fact that the yellow dots fall on a more or less straight line does not alone prove that radiocarbon ages equal true calendar ages.
The easiest way to see this is to simply plot the radiocarbon ages against the calendar ages—the ages that secular scientists assigned to the Lake Suigetsu varves (Figure 3).
Therefore, the true number of counted varves was much less than the 50,000 claimed by D&W, probably between 15,000 and 25,000. Under the right conditions, tens of thousands of varve-like layering patterns form in the 4,500 years or so since the Genesis Flood.