304 J.D. TRUEMAN 
ite. Microscopic examination did not reveal any differences 
between the minerals present in the schist and those in the quartz- 
ite. The zircons from the two rocks are illustrated in Figs. to and 
11. Many of the grains appear to be more or less rounded but in 
quite a number of instances the original outlines of the crystals 
can be seen. Some of the zircons may have remained in the 
quartz grains during sedimentation but the coating of iron oxide 
Fic. 1o.—Zircons from quartzite, Fic. 11.—Zircons from _ sericite 
Waterloo, Wis. X32. schist, Waterloo, Wis. X32. 
around practically every crystal seems to indicate that this was not 
generally the case. 
‘The following analyses of material obtained by combining 
samples from three localities in the area were made for the writer 
by O. L. Barneby, of the University of Wisconsin. 
Quartzite Sericite Schist 
TEAK Satta ease nan ears Te I.00 28 
VASO eee ore Er Saks .25 45 
These may be compared with the analyses of J. H. Warner. It 
must be remembered, however, that these pairs of analyses were 
made from different samples and one set cannot be regarded as the 
complement of the other. 
