REPORT OF THE DIRECTOR I917 



89 



Nodular bog manganese was found on the top of a small 15-foot 

 north-south ridge of vertically inclined beds of Rensselaer grit 

 mantled with humus and glacial detritus, above and directly west 

 of the bog just described. 



In the bed of a dry brook leading across the ridge from the circular 

 black muck bog to the larger bog 15 feet below, numerous brownish 

 black subspherical nodules of bog manganese were found, the dis- 

 covery of which led to further investigation by drilling and trenching, 

 the result of which was that an area of about 625 square feet was 

 found to be underlaid by nodular manganese to a depth of 2 feet, 

 the upper 11 inches of which consisted of a nodular wad and the 

 lower 6 inches of a massive or consolidated nodular aggregate, the 



w 



Cla 



Nodulav 

 Wad 



Soil 



Gvit * 

 Sch.sb 



8c ale H <> Y ^o"fal I s' 



ve> ti col 



30 



Fig. 1 Gott-Mesick manganese bog locality, Spencertown, N. Y. 



latter type occurring either as fragments about a foot or more square, 

 or forming a more or less continuous lenslike bed overlying a whitish 

 clay. Through the more massive manganiferous bed and between 

 it and the underlying whitish clay, water was in circulation, flowing 

 doubtless from the upper circular bog to the lower bog. 



Reference to the accompanying figure will suggest to the reader 

 that a probable genesis of the manganese may be assigned to the 

 swamp waters circulating through the top of the ridge from the 

 upper bog to the lower. This subject, however, is considered later 

 on. 



In the two closely adjacent areas it may be safely said, after 

 drilling and trenching, that bog manganese underlies about 825 

 square feet and that altogether there are about 1250 cubic feet of 

 manganiferous soil, allowing ih feet for an average thickness. It is 



