GEOLOGY OF THE NORTHERN ADIRONDACK REGION 353 





1 





o 

 o 



i 



4 



o 





MgO 



5.21 



8.12 



.35 



.95 



.26 



2 



CaO 



8.09 



8.03 



3.06 



1.12 



2.2 



.76 



Na,0 



3.48 



3.73 



5.06 



5.85 



3.5 



5.45 



K 2 



1.89 



1.64 



5.15 



5.62 



5.9 



5.01 



ILO 



1.13 



2.39 



.3 



1.45 



.4 



.91 



TiO a 



3.6 



.03 



.07 









P 2 6 



06 



.39 







.03 





CI 



21 



.18 









F 





.26 











Cr 2 3 





.06 













. . . .06 



trace 



trace 



.40 



.1 



.23 



BaO 



.04 



.04 



.13 





.05 





Total 



100.06 



100.2 



99.73 



99.87 



100.22 



100.05 



Q=C1 & F 



.05 



.14 











100.01 100.06 



1 Gabbro (hyperite) from near Nicholville, St Lawrence co. ; no. 2 of first 



table of analyses. 



2 Diabase, Bellmont township, Franklin co. ; no. 4 of second table. 



3 Angite syenite, Loon lake, Franklin co. ; typical ; no. 11 of first table. 



4 Normal syenite porphyry, Rand hill, Clinton co. ; no. 7 of second table. 



5 Quartz angite syenite, near Willis pond, Franklin co. ; no. 14 of first table. 



6 Quartz syenite porphyry, Rand hill ; no. 9 of second table. 



A comparison of the first two of the above analyses shows a very 

 close agreement betw r een the gabbro and the diabase in composi- 

 tion, the most striking discrepancy being in the titanium percent- 

 age. This difference is perhaps sufficiently pronounced to throw T 

 some doubt on the magmatic relationship, since in other respects 

 the analyses might be duplicated from many parts of the earth's 

 surface, both gabbros and diabases of this approximate composi- 

 tion being among the most widespread of igneous rocks. If this 

 high titanium percentage w T as characteristic of the rocks of the big- 

 intrusions, it should appear in the diabases, also if they are con- 

 genital. But, so far as the analyses go, they do not indicate a high 

 titanium percentage in the big intrusions except in the basic gab- 

 bros, and most of the analyses which have been made of them are 

 from specimens taken from the wall rocks of titaniferous ore 

 bodies, which are segregations from the magma which are extra 

 rich in iron and titanium. It is therefore thought likely that 

 this difficulty in the way of ascribing magmatic relationship is 

 more apparent than real. 



