They have no evidence of "multiple" ice ages, just that one
Then people wonder why myself and others say you are the epitome of "anti-science".
Oh, there is clear evidence of there having been multiple ice ages. The oldest some 3 gya, called the Pongola Glaciation. Now how extensive that event is we do not know at all, we can barely even guesstimate at where the cratons were at that time to make up continental placement. But the existence and dating of diamicite in Southern Africa has proven it happened.
Then there is the Huronian Glaciation some 2 gya. Evidence of that was found around Lake Huron in relationship to the "Great Oxygenation Event" that was occurring at the same time.
Then you have one I have brought up many times before, which I for brevity call the entire Cryogenian Age. A period from around 635 to 720 mya where almost the entire planet was covered in ice. The name itself comes from the Greek for "Frozen". This one we actually have a hell of a lot of evidence for, most especially the "Great Unconformity", where roughly a billion years of the geological record globally was simply wiped from existence. This can clearly be seen in the Grand Canyon, where 550 mya rocks are sitting right on top of 1.7 gya rocks. An entire billion years scrubbed away by glacial activity.
And there multiple other "Ice Ages" between then and the Late Cenozoic Ice Age, which we are actually still in today. That started some 34 mya with the Late Paleogene Glaciation, and we are some 3.5 my into the current Quaternary Glaciation.
And of that one we can clearly see there have been multiple "Ice Ages". One simply has to look at the deposits of the deposits left behind by three of them in North America. The Wisconsin, which technically we are still in the end stages of. And the Kansanan and Nebraskan, which also left behind clear geological proof.
"No evidence" indeed. There is a ton of evidence of multiple ice ages. You are over 100 years out of date, because the fact there have been multiple ice ages has been accepted by geologists for over a century now. The only issue is that most of the evidence for them has been erased, but we can clearly see from the evidence left behind that extended beyond the LGM that there have been multiple events.
Hell, in the chart above you can even see indirect evidence of another glaciation. It is no longer present on the surface, and it likely closely matched the Kansanan Glaciation. But notice the outflow that is pointed out at the mouth of the Mississippi of existence of MDT (Mean Dynamic Topography), showing extensive evidence of massive sediment deposits left behnd between 640-700 kya. And notice, that is a time that predates the Kansanan Glaciation, by the right amount of time to have been a full glacial cycle prior.
So in the above map, you can clearly see the evidence of 3 different Ice Ages. Both directly on the surface, and from marine sediments. For many ice ages, the only evidence left is either marine sediment or Antarctic Ice Cores because those events were the same size as the Wisconsin Glaciation or smaller, so the evidence was erased. But there is still clear evidence of multiple ice ages, dating back over a million years on the surface.
science.nasa.gov
