| Reference | {Deposit:: COX, DENNIS P., AND BRIGGS, REGINALD P., 1973, METALLOGENIC MAP OF PUERTO RICO: U.S. GEOLOGICAL SURVEY, MISCELLANEOUS GEOLOGIC INVESTIGATIONS MAP I-721, ACCOMPANIED BY EXPLANATORY PAMPHLET, 6 P.}{Deposit:: GUILLOU, R. B., AND GLASS, J. J., 1957, A RECONNAISSANCE STUDY OF THE BEACH SANDS OF PUERTO RICO: U. S. GEOLOGICAL SURVEY BULL. 1042-I, P. 302.} |