here’s an even better one explaining WHY varve dating is innacurate- and proving your link’s claims are false!:
“Varves
A common argument against the Bible involves varves—rock formations with alternating layers of fine dark, and coarse light sediment. Annual changes are assumed to deposit bands with light layers in summer and dark layers in winter. It is reported that some rock formations contain hundreds of thousands of varves, thereby ‘proving’ the earth is much older than the Bible says.[9] But the assumption that each couplet always takes a year to form is wrong. Recent catastrophes show that violent events like the Flood described in Genesis can deposit banded rock formations very quickly. The Mount St. Helens eruption in Washington State produced eight metres (25 feet) of finely layered sediment in a single afternoon![10] And a rapidly pumped sand slurry was observed to deposit about a metre (3–4 feet) of fine layers on a beach over an area the size of a football field (cross-section shown on the right: normal silica sand grains are separated by darker layers of denser mineral grains like rutile).[11]
When sedimentation was studied in the laboratory, it was discovered that fine bands form automatically as the moving water transports the different sized particles sideways into position (right).[12] Surprisingly, the thickness of each band was found to depend on the relative particle sizes rather than on the flow conditions.[13] A layered rock (diatomite) was separated into its particles, and when redeposited in flowing fluid, identical layers formed.[14]
Much is often made of the Green River varves,9 in Wyoming, USA. But these bands cannot possibly be annual deposits because well-preserved fish and birds are found all through the sediments.
It is unthinkable that these dead animals could have rested on the bottom of the lake for decades, being slowly covered by sediment. Their presence indicates catastrophic burial. It is often claimed that the fish and birds remained in prime condition at the bottom of the lake because the water was highly alkaline and this preserved their carcasses.[15] Yet highly alkaline water causes organic material to disintegrate, and that is why alkaline powder is used in dishwashers! Another problem for the varve explanation is that the number of bands is not consistent across the formation as it should be if they were annual deposits.[16]:”
http://www.trueorigin.org/walkergeo01.asp