If there really have been over thirty different ice ages, you might expect to find the evidence for one or two of these in the cores. The uniformitarian belief that the ice sheets have existed for millions of years and have been in equilibrium for perhaps 200,000 to 400,000 years predicted that they should find evidence of more than one major glaciation. While there is some disagreement on the origin of the bottom ice, it’s generally agreed that the previous ice ages were not found in the Greenland cores. They expected to find at least evidence of previous ice ages, however, even though researchers were quite confident more than one ice age would be drilled through, the evidence never materialized (Dansgaard 379, GRIP members, p.203, Science) The article by Koerner and Fisher suggests that warming in the last interglacial period caused the Canadian ice caps to completely melt away and the Greenland ice caps to also undergo massive melting. (Koerner, 19).
This is a possible explanation for the missing evidence of previous ice ages but it is also an admission that the existing ice sheet was the accumulative result of only one ice age, the most recent. Some claims have been made for multiple ice ages in the Antarctic cores, but these have been based solely on the assumption of the Milankovitch mechanism and uniformitarian beliefs, and lacking observational support. The other problem with this idea of complete melting is that we are in an inter-glacial period now, and the ice caps are still well in tact.
In their article on the sub glacial morphology of southeast Alberta, Claire Beany and John Shaw reexamined the evidences that had previously led to the hypothesis of multiple glaciations in that area of Alberta. They examined the amount and type of erosion and the small amount of glacial deposits at the edge of the area and the type and condition of the rocks and gravel found in remaining tills. The conclusion they make is that the evidence does not fit well with the idea that the area had been swept through by multiple glaciations (Beany, C. and Shaw, J. p.51).
Like many other scientists, they have discovered that much evidence originally thought to “prove” multiple ice ages was misinterpreted. In fact, when the theory of orbital induced ice ages was first conceived many valid arguments were brought against it. However the generation of scientists today are largely unaware of these arguments, and have accepted the astronomical theory as a well established fact.
The valid arguments of the past though have not been answered and new understanding of how Glaciers move and create till layers present very stout evidence against the present paradigm. These new interpretations along with the fact that large parts of the far north were never glaciated at all pose a serious threat to the multiple ice age theory and its associated long expanses of time. However, popular scientific paradigms don’t get over thrown easily
This is particularly true when they help support the long time spans that Charles Lyell originally inserted into geology, with the express intent of over throwing Flood Geology. And when they are the underlying basis for the theory of run away climate change caused by carbon increase due to fossil fuels.
The belief in multiple ice ages is thus a theory which exists in the minds of men only, the evidence for which is sadly lacking in the ice itself, as well as on the land.
Koerner, R. and Fisher, D Ice core evidence for widespread glacial retreat in the last interglacial ,Annals of Glaciology, vol.35, No.1, Jan. 2002, pp.19-24.