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To: E. Charters who wrote (32251)	2/8/2007 10:09:04 AM
From: jpthoma1	Read Replies (2) \| Respond to of 78421

VMS deposits are produced by a very slow precepitating process. You and me agree that the Sudbury deposits were probably formed during a cataclasmic event (you say a volcanic eruption, I prefer a meteoritic impact). According to some theories, the moon was formed from the original earth material. May be there were also meteorites that were formed from earth material and one of them came back to hit the earth 1,850,000 years ago. Unfortunately, stromatolites and multicellular algea living at that time were not able to write or take photos. So, we have no idea of what has happened! ;o) JP

To: E. Charters who wrote (32251)	2/8/2007 10:51:52 AM
From: hank2010	Read Replies (1) \| Respond to of 78421

Dietz originally postulated in the mid 60's that the meteorite contained nickel. That concept was dismissed by the majority of the scientists working on the sudbury event. It is generally agreed that the meteor struck an area where there existed an ni/cu rich ultramafic body. from Naldrett "there is a growing body of isotopic evidence that the complex is an impact melt that incorporated Ni, Cu and PGE bearing mafic and/or ultramafic rocks that were already present in the target area (Keays and Lightfoot, 1999; Cohen et al., 2000)" Naldrett also answers your questions about temperatures. "the most recent major contribution to our understanding of sudbury comes from the use of a modified computer code developed at Los Alamos (Amsden et al, 1980) to simulate the behavior and temperature of target rocks during a cratering event. Ivanov and Deutsch (1999) applied this to sudbury and then used heat flow equations to estimate temperature variations in the resulting impact melt. their calculations indicate that the maximum temperature within a 2.5 km thick impact melt sheet would be about 2000 degrees K at the time of impact and that the temperature would remain above 1450 degrees K which is the approximate liquidus, for 250,000 years. This extended period of superheat explains many features .... it also explains the distribution of the sulphide ore"

To: E. Charters who wrote (32251)	2/8/2007 11:13:39 AM
From: hank2010	Read Replies (1) \| Respond to of 78421

With respect, Eric. I do not have the academic qualifications of JP or yourself. However, I have been in and out of the Sudbury area quite often over a great number of years. when I was a kid I heard people talking of your VMS hypotheses. I have not heard anyone (til now!)defend the volcanogenic origin of the basin. I have attended talks by Dr. Naldrett, by Dr. Walter Peredery of Inco, By Dr. Burkhart Dressler of the Ontario Geological Survey and by numerous other geologists from Inco and Falconbridge who work in the Sudbury area every day. I look at the references cited by Dr. Naldrett in his 2002 presidential address I referred to. There are Yanks from Colorado, Los Alamos, Stanford, Berkely, NASA, the U.S. Navy, Germans, Russians, South Africans, Australians, Brits, and Koan even found some in New Zealand whose work supports the impact theory. There are numerous other impact craters being studied around the world. This work supports the work done at sudbury. With respect! I think your references from 1948 and the early 1960's are outdated. You refer to Pat Sheridan. He is a very successful man in the mining explor. and dev. business. But I think Pat would be the first to acknowledge Naldrett, Peredery, Dressler and a host of others are more qualified on this subject. There are hundreds of millions of dollars being spent by companies in the sudbury area under the direction of many brilliant geoscientists. I have not met one in the last 30 years who still subsribe to the theories you talk about. You are definitely in the minority. If you are correct, you should consider being involved in exploration in the Sudbury Basin. You would surely pick up on a lot of stuff overlooked by those using an incorrect theory.