Please note that the number of varves increased as you went from the center of the basin to the outside edges. The four black lines are rivers bringing in fresh water.To fully understand this, consider this simplified diagram of a closed lake system. The sources of the sediments forming the varves are brought into the lake by the rivers.The investigators concluded that this was inconsistent with the idea of seasonal ‘varve’ deposition in a stagnant lake.REBUTTAL: Actually, this supports the old earth model.At this rate, the storms would be so constant that you would not get the finely layered couplets that we see in the rocks, nor is it realistic to say that it rained that much in that location over the last 10,000 years.(Lower it to 6,000 years, which most young earth creationists claim as the age of the earth, and you have 500 storms per year!As the young earth argument points out, between these two ash layers, the number of varves varies.
This is due to the increased precipitation during summer, thus you have more water entering the lake.
The closer we get to the center, we would expect to see less sediment from the rivers, hence, less varves.
Therefore, the layers between the volcanic ash would reflect this pattern of less layers in the middle. Why then did the scientists they mention not see this? Either they overlooked this simple observation, or they saw only what they wanted to see (i.e. REBUTTAL: I agree, you can deposit volcanic ash in fine layers very quickly.
Horizontal bedding structures exist in many types of depositional environments, such as lake bottoms, gently sloping beaches, or in a deep marine environment.
One of the main categories of horizontal bedding is known as "rhythmites." A rhythmite is bedding that is in a repetitious sequence, generally thin, and contains alternating types of sediment particles. In a varve, there are alternating layers, with a thicker, coarser layer, followed by a thinner, fine-grained layer.