of the marsh as I understand it, the first is the diurnal one 

 which Dr. Redfield has mentioned, concerned with the ebb and 

 flow of each tide, and that movement is more pronounced the 

 nearer you are to a creek and it also, I think, depends upon the 

 height of the tide that is involved. That is, if you are dealing 

 with a spring tide I think the movement is likely to be greater 

 than if you are dealing with a neap tide. There is, in addition 

 to that, what I call the spring tidal cycle movement of the water 

 table as well, and the diurnal movement if superimposed upon 

 this spring tidal cycle movement so that during the neap tide 

 period the water table will be lower in the marsh initially than 

 it is at the height of the spring tidal cycle movement. 1 do not 

 know whether that is going to add a further complication to the 

 picture that Dr. Redfield has outlined, and 1 would rather like 

 to have some views on that. Personally the thing that interests 

 me most is Dr. Redfield's statement that there is no substantial 

 movement. His data indicate no substantial movement of the 

 water table. I would have thought that there comes a point when 

 you approach a creek where quite clearly there is a substantial 

 movement of the water table. Whether using this technique you 

 could find that point 1 do not know. 



Redfield: Well, I take no exception to any of the things you have suggested. 



This was a job which was going to require a long time. I did not 

 understand it at the beginning. I did not know very well what to 

 expect. 1 selected a point which was as accessible as possible 

 so that 1 could drive out onto the marsh on a road which was 

 available. 1 was 100 yards from the foreshore, which was about 

 halfway between the foreshore and the large creek which came 

 in, and there were drainage ditches of course - the small mos- 

 quito ditches, not very deep. 1 could find a more remote spot. 

 I didn't think that was very important at this stage. The point 

 is, if this is reasonable, you have an extremely convenient 

 method of quantitating things from relatively few movements and 

 obviously my next task is to go as far out in the middle of the 

 marsh as I can and repeat at least some of these determinations. 

 Just where the water table is, I think, is very hard to say. This 

 is an asymptotic curve. Several feet in the marsh there is no 

 detectable chlorinity. There is no sharp boundary line. There 

 is, however, a place down here where you change very abruptly 

 into glacial till with gravel, glacial stones and so on. It is in- 

 teresting to remark that this mean temperature, which is about 

 10. 5° C. and which is just about the temperature of well water, 

 is just about the temperature of the bottom of these ponds which 

 occur in depressions in the moraine - depressions below the 

 water table - the water at the bottom of those ponds remains at 

 about this temperature all summer after the thermal stratifica- 

 tion begins. These ponds begin to stratify only when the surface 

 temperatures begin to get above 10.5; so we have certainly tied 



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