14 THE CUB A It E V I E W 



GEOLOGY AND TOPOGRAPH Y 



All the deposits of chrome ore examined are in serpentinized basic rocks. Fibrous 

 spots resembling asbestos commonly occur in serpentine near the ore bodies. The 

 deposits are lenticular and tabular masses ranging in thickness from 1 foot to more 

 than 50 feet, and reaching a maximum length of more than 200 feet, but they may 

 include small masses of serpentinized peridotite. Thin veinlike streaks of ore have 

 also been noted. The ore bodies appear to be charactristic magmatic segregation 

 deposits and resemble many of those found in masses of serpentine in California 

 and Oregon. 



The ore is generally fine grained to medium coarse grained, and varies from 

 spotted material consisting of black grains of chromite, ranging in diameter from a 

 thirtieth to a quarter of an inch, embedded in white or light-green serpentine, to 

 solid black material containing little or no visible serpentine. Fine seams of a green 

 crystalline mineral, uvarovite, a calcium-chromium garnet, are occasionally found in 

 the ore. 



Most of the masses of ore are highly inclined, and certain of them that are ex- 

 posed in ravines on steep hillsides in mountainous or hilly regions dip at about the 

 same angle as the hillsides. The deposits west of Nipe Bay are in areas of moderate 

 relief; those near Camaguey are in an area of very low relief. The deposits in the 

 eastern part of Oriente Province, which are the largest, are in mountainous country 

 and are very difficult of access. 



HAVANA AND MATANZAS PROVINCES 



In the eastern part of Havana Province small pockets of chrome ore have 

 been found at a point about two miles from the railroad. A little mining has been 

 done here on the Elena claim, from which, it is reported, about 600 tons of ore have 

 been shipped. In Matanzas Province small deposits of ore have been found on the 

 Jack claim, about seven miles northwest of the railroad station at Mocha, and on 

 the Ana Maria claim, about ten miles west of Cardenas. This claim is only two 

 miles from a railroad, but no ore has yet been shipped from it. Considerable de- 

 velopment work has been done on the Jack claim and there was a total stock of 

 about 450 tons of ore on hand in February, 191S. 



An analysis by the United States Geological Survey of a composite sample of 

 ore taken from two bins at this mine gave the results shown under 1 in the following 

 table, and analyses A and B, made by Ricketts & Co., of New York, represent sam- 

 ples obtained by trenching separately the two bins of ore. 



ANALYSES OF CHROME ORE FROM STOCK AT JACK MINE, NEAR MATANZAS 



1 A B 



Cr 2 O 3 43.0 36.52 35.84 



Fe 13.0 12.3 11.85 



Si O 2 5.4 6.66 6.73 



Al 2 O 3 15.0 



S Tbace. 



p None. < >.4 .03 



Xi Present. .... 



Probably no ore can be shipped in the near future from any of these deposits 

 beyond possibly 500 tons, now mined. The geologic conditions in these areas, how- 

 ever, warrant further exploration. 



CAMAGUEY PROVINCE 



The deposits of chrome ore examined in Camaguey Province consist of three 

 groups, which lie along a narrow zone beginning about nine miles northeast of the 



