THE BEHAVIOR OF INCLUSIONS IN IGNEOUS MAGMAS 551 



reaction of such magma with aluminous sediments. A suggestion 

 along similar lines has already been made by Evans."^ 



An example of the reaction of basic magma with aluminous sedi- 

 ments, in which the relations discussed seem particularly clear, is 

 afforded by the so-called Cortlandt series.^ The early work of 

 Williams and the later work of Rogers on this series treats in some 

 detail the features bearing upon the question here at issue.^ The 

 Cortlandt series is intrusive into the Manhattan schist (locally into 



TABLE III 



I. Manhattan schist. Composite analysis of five specimens be- 

 yond border of the Cortlandt series. Analyst, G. S. Rogers. 



II. Manhattan schist on contact of Cortlandt series. Analyst, F. 

 L. Nason in G. H. Williams, Amer. Jour. Sci. (3), Vol. XXXVI (1888), 

 P- 259. 



other formations also) and the interaction between schist and 

 magma is in places rather well displayed. The Manhattan schist 

 is a metamorphosed sedimentary rock of the nature of a shale. Its 

 composition, as given by a composite analysis of five specimens, is 

 shown in Table III under I. No doubt it varies considerably from 

 this average and is sometimes more aluminous, but it is always far 

 from the composition of kaolin, which composition we have used 



' J. W. Evans in discussion of paper by C. E. Tilley, Quar. Jour. Geol. Soc, Vol. 



Lxxvn, p. 133. 



^ G. H. Williams, Amer. Jour. Sci. (3), Vol. XXXI (1886), p. 26; (3), Vol. XXXIII 

 (i887),pp.i3S,i9i; (3), Vol. XXXV (1888), p. 438; (3), Vol. XXXV (1888), p. 254. 

 3 G. S. Rogers, Atift. N.Y. Acad. Sci., Vol. XXI (1911), pp. 11-86. 



