Hi Giorgio,
I think you might have misunderstood my point--typical of email which can be easily misunderstood.
I highly applaud your effort and totally agree with you that these places are spectacular places to do geology. Like you, I've spent a lot of time on these kinds of exposures and it saddens me when the alder bushes advance across those beautiful rocks! I think your effort is great for all of us who work in areas like this because it allows us to point to the time sensitive nature of doing some of this work--maybe we need to go to the biology literature and look for information on how fast bushes take over! I think your point is well taken--like many other issues, we'll have to pick sites that really do have important relationships and concentrate on those. We can't look at all these things.
thanks for the thoughts,
Terry Pavlis
-----Original Message-----
From: Tectonics & structural geology discussion list [mailto:[log in to unmask]] On Behalf Of Giorgio Pennacchioni
Sent: Friday, April 27, 2012 3:28 AM
To: [log in to unmask]
Subject: Re: GLACIER WATCH: announcement
Hi Terry,
it it clear that we cannot compete with the retreating glaciers and that it is impossible to record all the structures that, once exposed,disappear in a short time. Many exposures are in remote areas and we will never know about. Even easy accessible areas takes time to be carefully mapped and, as you point out in your email, an army of well-funded flying geologists would not be able to make even a small part of job in just a small region of Alaska.
The point is that these glacier-polished surfaces provide us with the most spectacular exposures and, where nice structures are exposed, they are simply text book types. The glaciated outcrops are in many cases relatively flat and allow detailed mapping over large areas; the geometry of the structural network can be mapped with a detail which is impossible in other areas, and therefore gives valuable information on development of complex structural arrays. As you state in you email: "We published a detailed map of a spectacular glacial exposure there (Pavlis and Sisson, 1995, GSA bulletin), but that one is almost already too late-last I flew over it, it was getting seriously overgrown by alder brush. that was about 4 years ago, so it is even worse now. The exposure has one of the most spectular exposures I've ever seen of refolded folds, and a progressive metamorphic sequence that goes across a transition fro schists to migmatitic gneisses."
So: what is the suggestion. I remember that a few years ago, a dam was built in Turkey, that was going to submerge an important large archeological site. The archeologists were left a few days to save what they could. They made a selection working hardly day and night and some important masterpieces escaped destruction. We are in a more-or-less similar situation. We cannot "save the world", but we can save some unique area/outcrops before they get lost for ever.We ask people working in glaciated areas to make a selection of the few outcrops they repute exceptional, that should not be missed (and that they cannot map by themselves) and to submit to GW. We will publish the information on Glacier Watch and see if we can form the "small army" of researchers willing to be part of the "rescue team" of the area. Of course, the attraction for being part of the study group will be also related to the scientific implications of the study. For the most exceptional areas not-to-be-lost, we can try to find some financial support.
Let me just say that in my last 20 years I have mainly worked in the front of retreating glacier. The area I covered with detailed mapping is ridiculous in terms of square meters, but those outcrops have provided me with the best examples of structures and maps of my career. In a glaciated outcrop there is nothing you have to imagine about geometry: exposure is 100% and the polishing effect of the glacier allows details down to the gain scale to be directly seen in the field.
It would be great if we can gather a group of volunteers, as part of a GW team, with "representatives" from the different parts of world that have the specific expertise to help in identifying and select the suitable areas for the study. The project is at its start, and we need any fresh (which in this cases seems appropriate) input and idea to take over.
Best regards
Giorgio Pennacchioni
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