The Creede mining district in the central San Juan Mountains of southwestern Colorado is located along a zone of recurrent faulting just north of the Creede caldera. The character, distribution, and age relations of late faulting and mineralization in this zone suggest that a local stock was emplaced beneath the Creede district in earliest Miocene time, about 24.6 m.y. ago. This postulated stock may be reflected in an observed local gravity low and in what appears to be a group of irregular, low-amplitude magnetic highs and lows that are isolated with considerable difficulty from other anomalies of greater amplitude adjoining them.Mineralization took place in a near-surface environment along concurrently active distentional faults, and both the faulting and mineralization apparently were related to emplacement of the underlying intrusion. Ore was deposited largely along open fractures near the zone where ascending and descending solutions mixed. Most known ore is in the zone just outside the topographic wall of the Creede caldera near where faults cutting the rigid, brittle, and impervious volcanic units intersected the water-filled, marginal, coarse-clastic facies of the sedimentary Creede Formation in the moat of the caldera.

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