THE CONNECTIONS 65 



is too flat and uncharacteristic for sure connections. Very fat 

 clay requires great caution. A section may look perfect, but 

 nevertheless be valueless. At locality 78 measurements a few 

 yards apart, of apparently good series, showed more disagreement 

 than correspondence, because the clay, which resembles green 

 soap in consistency, had been compressed. Another danger is 

 that series of varves of such clay can have slidden away with- 

 out leaving any trace, even in a long clean section. However, 

 by controlling the measurements with those made at other 

 localities mistakes can be avoided. 



Abundance and Quality of New England Material 



The deposition of varve clay in New England occurred under 

 very favorable conditions. The varves are, as a rule, very well 

 developed and of good thickness, and the series show good cor- 

 respondences almost without exception. Very often the agree- 

 ment is quite striking. The large amount of material at my dis- 

 posal has made it possible to control the measurements varve by 

 varve and to discard poor material, as explained on page 47. 

 Often the connections, based on agreeing curves, are supported 

 by such peculiarities as drainage varves and changes in con- 

 sistency and color of the clay. 



Examples of Individual Curves to Illustrate 

 Agreement Among Them 



At the bottom of Plate V, parts of original curves are repro- 

 duced so as to give some illustration of their correspondence with 

 one another. There are three groups of curves, the first com- 

 prising localities 1 and 4 (box I), the second localities 15, 18, 

 and 24 (box II), and the third localities 82, 90, and 91 (box 

 III). 



Localities 1 and 4 lie 6.4 miles (10.4 km.) apart, the latter that 

 much closer to the ice edge (Fig. 5). No alterations whatever of 

 the graphs have been made, since the original measurements 



