I think I said before that the recent glacial era, the late Pleistocene is actually a string of riddles. One of them is the Mystery interval. As the ice core indications in Antarctica suggested a clear warming around 19-18,000 years ago, the ice cores in Greenland did not show anything. On the contrary, the proxies for temperature appeared to dip at 17,500 years until a very sudden jump up at 14,500 years ago. Originally known as the 'Oldest Dryas' it's now the Mystery Interval, especially because detailed studies on areas give conflicting results (Denton et al 2006)* So here is a fresh article about the Mystery Interval: Carlie Williams, Benjamin P. Flower and David W. Hastings, 2012, Seasonal Laurentide Ice Sheet melting during the "Mystery Interval" (17.5-14.5 ka), Geology, published online on 9 August 2012 as doi:10.1130/G33279.1 First impression is that if the Younger Dryas is equally enigmatic, how can you endorse an meltwater rerouting hypothesis, in the face of several conflicting evidence (more later) and other ideas? However I'm going to read it carefully, maybe we find a gem. *Denton G.H., Broecker, W.S. and Alley, R.B., 2006: The mystery interval 17.5 to 14.5 kyrs ago, PAGES news, 2: 14-16.