CLASSIFICATION OF THE ROCKS. 



113 



magnetite, whilst in the remaining 9 ores the latter mineral predomi- 

 nates. The average percentage of the combined oxides is 77*04, of 

 which 43*83 is in the form of magnetite, and 33*22 in the form of 

 hematite. The following table shows the results of the calculations 

 for each specimen : — 



Salem Magnetic Ores. 





Oxides found by analysis. 



Minerals calculated from 

 analysis 



Locality. 









FcO 



Fe 2 3 



Magnetite. 



(FeO 



Fe 2 3 .) 



Hematite. 

 (Fe 2 3 .) 



Karjamalai 







20*07 



75*20 



64*67 



30*60 



Ditto 







3*56 



48-10 



11*46 



40*2O 



Ditto 







U'62 



33*i3^ 



37*42 



12*33 



Ditto 







30-03 



66-72 



96*75 



Nil. 



Ditto 





• 



17-72 



70*98 



57*12 



3i*b8 



Ditto 







2373 



69-29 



5 6 *47 



36*55 



Kollimalais, south of . 







22*38 



74*77 



7172 



25'43 



Namagiripett • • 







2*07 



51-10 



6*67 



46*50 



Ditto 







17*68 



78-07 



56*96 



3879 



Ditto 







17-36 



77*95 



55%° 



39*35 



Ditto 







4*H 



4foo 



13*34 



3 i*8c 



Ditto 







4-96 



40-44 



i5*93 



29-42 



Mathurutu 







16*10 



68-12 



51*90 



32*32 



Ditto 







11*67 



77*64 



37*61 



51*70 



Ditto 







14-09 



77*51 



45*41 



46*19 



Murugathumalai 







6-78 



53*75 



21*84 



38*79 





^ 



43*83 





Av 



ERAG 



E 



77-04 



33*22 



( " ) 



