ECONOMIC GEOLOGY. 231 



THE MAIMdN IRON DEPOSITS. 



Senor Leon Sanchez, of Maimon, guided us to his iron prospects on Loma 

 Pegado, a hill about 4 kilometers southwest of Maimon. This hill is com- 

 posed of serpentine, which is an alteration product of some basic igneous 

 rock. All the hills near Maimon are apparently composed of similar rock, 

 but none except Loma Pegado was examined. Near the top of Loma 

 Pegado a black trap rock, hornblende diabase, which is probably part of a 

 dike intruded into the serpentine, is exposed in a prospect pit. 



There are numerous prospect trenches and pits on the flank of Loma 

 Pegado. They expose serpentine cut by plates and banded, botryoidal, and 

 drusy veinlets of quartz. The serpentine has weathered for a depth of more 

 than a meter below the surface, and the upper 30 to 50 centimeters is 

 changed to a red, very highly ferruginous residual soil. 



The conditions here are similar to those in the Mayari district of Cuba, 

 with the important difference that the deposits in the vicinity of Loma 

 Pegado are on steep hillsides, so that the amount of residual soil of possible 

 value as iron ore is very small, but commercial quantities of ore may be 

 found in the vicinity of Maimon in a more favorable topographic position. 



Apparently the prospecting on Loma Pegado was originally undertaken 

 in the hope of finding deposits of nickel. H. G. Ferguson made a hasty 

 examination at this locality and reports that small amounts of garnierite, 

 a silicate of nickel, occur in places in the serpentine but not in commercial 

 quantities. 



LA PERSEVERANCIA NICKEL DEPOSIT, PROVINCE OF SANTO DOMINGO. 



By D. Dale Condit. 

 Sierra Prieta, a part of the property known as "La Perse veranda" con- 

 cession, was visited on June 10 and July 6, 1918, by H. G. Ferguson, of the 

 United States Geological Survey, and on June 16, 1919, by the writer, 

 while he was in the service of the Dominican Government. 



HISTORY OF CONCESSIONS. 



The "Perseverancia" concession was granted to Senor Manuel Delmonte 

 on January 13, 1915. The "denouncement" which went with this conces- 

 sion mentioned iron, chrome, manganese, cobalt, nickel, copper, and gold 

 in both quartz and placers. The localities included El Cerro Pelada, El 

 Mongote, Mirador, Leonora, Guamuna, Isabela, Matiguelo, Sierra Prieta, 

 Higuero and Maimon, parts of Communes Villa Mella, Yamasa, and La 

 Victoria, Santo Domingo Province. The ownership of the concession was 

 transferred from Senor Delmonte to Doctor Rogelio Diaz Pardo of Havana, 

 Cuba, in February, 1918. All the exploratory work since the advent of Dr. 

 Pardo has been done at a locality known as Sierra Prieta. The accompany- 

 ing map of Sierra Prieta (PI. XXII) is a reduction, after redrafting, of the 

 map filed in the office of the Secretario de Fomento y Comunicaciones. 



