Ore controlALL MINERALIZATION IN DISTRICT LOCALIZED IN POWDERHORN AND IRON HILL INTRUSIVE CENTERS AND ON CIMARRON FAULT, WHOSE POSSIBLE LATE PRECAMBRIAN MOVEMENT MAY HAVE LOCALIZED EMPLACEMENT OF ALKALIC/CARBONATITIC COMPLEX. FE AND TI OCCUR AS SEGREGATIONS OR DIKES WITHIN PYROXENITE STAGE OF INTRUSION. VERMICULITE LOCATED IN SIMILAR BIOTITE SEGREGATIONS BUT CONTROLLED BY DEPTH OF WEATHERING. NB, RAE, AND TH/U ;OCALIZED PRIMARILY IN MASSIVE CARBONATOTE STAGE OF INTRUSION AND IN RADIAL DIKES POSSIBLY CONTROLLED BY PRE-CARBONATITE FRACTURES IN ALKALIC ROCKS. TH AND RAE ALSO LOCALIZED IN VEINS AND TRACHYTE DIKES FILLING FRACTURES AND JOINTS IN OLDER PRECAMBRIAN GRANITIC AND METAMORPHIC ROCKS PERIPHERAL TO INTRUSIVE COMPLEX.
Geology
AlterationPRINCIPAL ALTERATION IS FENITIZATION OF POWDERHORN GRANITE, FINE- TO MEDIUM-GRAINED GRANITE, AND DUBOIS FELSITE BY MATASOMATISM ASSOCIATED WITH INTRUSION OF ALKALIC/CARBONATITIC MAGMATIC FLUIDS. GRADATION OF GRANITE TO FENITE CHARACTERIZED BY DECREASED QUARTZ, AEGIRINE-AUGITE REPLACING BIOTITE, MICROCLINE BECOMING GRAYER, MORE PERTHITIC, LESS EUHEDRAL, DEVELOPMENT OF GNEISSIC OR SCHLIERIC TEXTURE. FENITIZED DUBOIS FELSITE CHARACTERIZED BY ALBITIZATION OF MICROCLINE. ALTERATION OF NEPHELINE TO ZEOLITES (NATROLITE AND ANALCITE) AND CANCRINITE IN UNCOMPAHGRITE, IJOLITE, AND NEPHELINE SYENITE. ALTERATION OF PYRITE TO FE OXIDES IN THORIUM VEINS, TRACHYTE DIKES, CARBONATITE, & PYROXENITE. ALTERATION OF PEROVSKITE TO LEUCOXENE IN PYROXENITE. ALTERATION OF BIOTITE AND PHLOGOPITE TO VERMICULITE IN PYROXENITE. SERICITIZATION IN FENITIZED GRANITE, DIABASE, AND NEPHELINE SYENITE. CHLORITIZATION OF PYROXENE IN PYROXENITE AND UNCOMPAHGRITE.