Unnamed 20-2

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.COX, D. P., MARVIN, R. F., M'GONIGLE, J. W., MCINTYRE, D. H., AND ROGERS, C. L., 1977, POTASSIUM/ARGON GEOCHRONOLOGY OF SOME METAMORPHIC, IGNEOUS, AND HYDROTHERMAL EVENTS IN PUERTO RICO AND THE VIRGIN ISLANDS: U. S. GEOLOGICAL SURVEY JOUR. RESEARCH., VOL. 5, NO. 6, P. 689-703.