238 GEOLOGICAL RECONNAISSANCE OF THE DOMINICAN REPUBLIC. 



by the Blanton Copper Mining Syndicate between October 1, 1915. and 

 July 5, 1917, inclusive. The ore, which is reported to have come princi- 

 pally from Bucaro Hill, was picked ore. About 10 tons were mined for 

 each ton shipped. The average value of the ore shipped was $57.70 per 

 ton. The highest assay for copper in the ore shipped was 16.9 per cent; 

 the lowest was 8.6 per cent. The highest silver assay was 2.80 ounces 

 per ton; the lowest was 1.30 ounces per ton. The highest gold assay 

 was 0.10 ounces per ton. None of the shipments contained valuable 

 quantities of silver or gold. 



Ore shipped from the San Francisco concession by Blanton Copper Mining Syndicate. 



Less than 500 tons — according to one report only 50 to 60 tons — was 

 shipped from San Francisco Hill, but no records of the shipments are at 

 hand, and the amounts and values are not known unless some of the above 

 mentioned shipments were made from the San Francisco workings. Two 

 tunnels were entered, and several caved workings on San Francisco Hill 

 were examined. Several hundred meters of tunneling and drifting has 

 been done here, and one small stope in the uppermost tunnel is still accessi- 

 ble. Much of the drifting, both here and on Bucaro Hill, was done along 

 barren slips and appears to have been of no value in developing the prop- 

 erty. 



Doctor Harootian's La Rama prospect, near the head of Arroyo Plata- 

 nito, has been just developed by four openings in the hill, the largest about 

 6 meters long. 



GEOLOGY. 



The mineralized area consists of volcanic rocks, principally tuffs and 

 breccias. Limestone crops out along the crest of the hills on the southwest 

 side of Rio Nigua. 



