Larson Volcano

The Larson Volcano is a silver, gold, copper, and lead mine located in Hinsdale county, Colorado at an elevation of 10,217 feet.

About the MRDS Data:

All mine locations were obtained from the USGS Mineral Resources Data System. The locations and other information in this database have not been verified for accuracy. It should be assumed that all mines are on private property.

Mine Info

Satelite View

MRDS mine locations are often very general, and in some cases are incorrect. Some mine remains have been covered or removed by modern industrial activity or by development of things like housing. The satellite view offers a quick glimpse as to whether the MRDS location corresponds to visible mine remains.

Site Name

Primary: Larson Volcano
Secondary: Larson Center

Commodity

Primary: Silver
Primary: Gold
Primary: Copper
Primary: Lead
Secondary: Zinc
Tertiary: Molybdenum

Location

State: Colorado
County: Hinsdale
District: Larson Creek Area

Land Status

Land ownership: National Forest
Note: the land ownership field only identifies whether the area the mine is in is generally on public lands like Forest Service or BLM land, or if it is in an area that is generally private property. It does not definitively identify property status, nor does it indicate claim status or whether an area is open to prospecting. Always respect private property.

Holdings

Not available

Workings

Not available

Ownership

Not available

Production

Not available

Deposit

Record Type: Site
Operation Category: Occurrence
Operation Type: Unknown
Discovery Method: Ore-Mineral In Place
Years of Production:
Organization:
Significant: N
Deposit Size: S

Physiography

General Physiographic Area: Rocky Mountain System
Physiographic Province: Southern Rocky Mountains

Mineral Deposit Model

Not available

Orebody

Not available

Structure

Type: R
Description: San Juan Volcanic Field, San Juan Depression

Type: L
Description: San Juan-Uncompahgre Calderas, Lake City Caldera, Larson Volcano

Alterations

Not available

Rocks

Name: Monzonite
Role: Associated
Age Type: Associated Rock
Age Young: Oligocene

Name: Monzonite
Role: Associated
Age Type: Host Rock
Age Young: Oligocene

Analytical Data

Not available

Materials

Ore: Pyrite
Ore: Molybdenite
Ore: Chalcopyrite
Ore: Sphalerite

Comments

Comment (Geology): CAUSED SIMPLE DOMAL RESURGENCE OF LAKE CITY CALDERA, WITH NE-TRENDING APICAL GRABEN FAULTING OVER DISTENDED CREST (REFLECTING SIMILAR TREND OF EUREKA GRABEN) AND CHAOTIC COLLAPSE BRECCIAS ON SW SIDE; (12) MIOCENE TO PLIOCENE REGIONAL EXTRUSION OF BIMODAL MAFIC-SILICIC (BASALTIC TO RHYOLITIC) FLOWS OF HINSDALE FM (18.8 TO 12.6 M.Y.) PERIPHERAL TO CALDERA COMPLEX AND RELATED TO INITIAL DEVELOPMENT OF RIO GRANDE RIFT AND REGIONAL EASTWARD TILTING OF EAST PART OF SAN JUAN VOLCANIC FIELD; (13) LATE TERTIARY AND QUATERNARY EROSION, DISSECTION, EXTENSIVE MASS WASTING, AND GLACIATION OF CALDERAS AND PERIPHERAL OUTFLOW DEPOSITS.

Comment (Commodity): METALS AND ORE MINERALS LISTED ABOVE (EXCEPT MO) ARE UNVERIFIED BUT BASED ON MINERALIZATION AT OTHER PERIPHERAL PRECALDERA VOLCANIC CENTERS AROUND SAN JUAN-UNCOMPAHGRE CALDERA COMPLEX.

Comment (Deposit): GENERAL GEOLOGY OF VOLCANO AREA CHARACTERIZED BY THICK SEQUENCE OF PORPHYRITIC ANDESITE, RHYODACITE, AND QUARTZ LATITE FLOWS AND FLOW BRECCIAS INTERBEDDED WITH ANDESITE/RHYODACITE EXPLOSION BRECCIAS, MUDFLOW BRECCIAS, LOCAL INDURATED SPATTER AGGLUTINATES, AND A FEW BRECCIATED LAVA FLOWS. SEQUENCE INTRUDED BY (1) PLUGS OF MONZONITE/MONZONITE PORPHYRY AND RHYOLITE PORPHYRY, AND (2) RADIATING DIKES OF ANDESITE/RHYODACITE PORPHYRY. EARLY INTERMEDIATE-COMPOSITION FLOWS/BRECCIAS AND INTRUSIVE ROCKS OF LARSON VOLCANIC CENTER CONSIDERED TO PREDATE FORMATION OF SAN JUAN DEPRESSION AND ASSOCIATED CALDERAS, THEREFORE REPRESENTING OLDEST STAGE OF MINERALIZATION IN CALDERA COMPLEX AREA. MINERALIZED CORE CONTAINS DISSEMINATED SULFIDES AND LOCAL VEINS (LIPMAN AND OTHERS, 1976, P. 577).

Comment (Workings): PROSPECT PITS AND SEVERAL SHORT EXPLORATORY ADITS.

Comment (Geology): WITHIN AND ON SAN JUAN-UNCOMPAHGRE CALDERA MARGIN; (8) BROAD EPISODIC RESURGENT DOMING ALONG NE-TRENDING AXIS OF SAN JUAN DEPRESSION: DISTENTION FRACTURING ALONG CREST PERMITTED DOWNFAULTING OF EUREKA GRABEN, EXTENDING FROM WITHIN SILVERTON CALDERA NE ACROSS MEDIAL SEPTUM (COMPOSED OF PRECAMBRIAN GRANITE) SEPARATING SAN JUAN AND UNCOMPAHGRE CALDERAS; (9) ERUPTION OF MIOCENE SUNSHINE PEAK SILICIC ALKALI RHYOLITE TUFF (23.0 M.Y.) WITH CONCURRENT COLLAPSE OF LAKE CITY CALDERA (NESTED WITHIN UNCOMPAHGRE CALDERA) ALONG SINGLE, CONTINUOUS VERTICAL TO STEEP INWARD-DIPPING RING FAULT; ASH FLOWS INTERTONGUING WITH COLLAPSE BRECCIAS; (10) FLOWS AND DOMES OF VISCOUS, SILICIC LAVAS (GRASSY MOUNTAIN AND RED MOUNTAIN QUARTZ LATITES)(23.3 TO 22.8 M.Y.) ISSUED FROM RING-FAULT VENTS ON EAST SIDE OF LAKE CITY CALDERA; YOUNGER EMPLACEMENT OF ENE-TRENDING CHAIN OF RHYOLITIC INTRUSIVES (18.5 M.Y.) IN UNCOMPAHGRE CALDERA MOAT AREA NORTH OF LAKE CITY CALDERA; (11) UPWARD MOVEMENT OF SHALLOW GRANITIC MAGMA

Comment (Geology): GENERALIZED EVOLUTION OF UNCOMPAHGRE-SAN JUAN, SILVERTON, AND LAKE CITY CALDERAS (LIPMAN AND OTHERS, 1973; STEVEN AND LIPMAN, 1976; HON AND MEHNERT, 1983): (1) ERUPTION OF EARLY OLIGOCENE (35.6 TO 31.9 M.Y.) INTERMEDIATE-COMPOSITION LAVAS, BRECCIAS, AND PYROCLASTICS (SAN JUAN AND LAKE FORK FMS), AND LATERALLY ASSOCIATED VOLCANICLASTICS FROM CLUSTERED CENTRAL-VENT SHIELD VOLCANOES (LARSON, CARSON, AND CIMARRON CENTERS) COMPRISED OF RHYOLITE PORPHYRY, ANDESITIC TO RHYODACITIC, AND MONZONITIC INTRUSIVES; (2) LOWER FLANKS AND COALESCING OUTFLOW APRONS OF SHIELD VOLCANOES COVERED BY ASH-FLOW SHEETS (UTE RIDGE (29.1 M.Y.) AND BLUE MESA TUFFS) FROM NEARBY UTE CREEK AND LOST LAKE CENTERS TO SE; (3) ERUPTION OF RELATIVELY SMALL VOLUME OF DILLON MESA TUFF (29 TO 28 M.Y.) PROBABLY FROM AREA OF INCIPIENT UNCOMPAHGRE CALDERA; (4) VOLUMINOUS ERUPTION OF WIDESPREAD SAPINERO MESA TUFF (CIRCA 28 M.Y.) FROM SAN JUAN DEPRESSION, CONCURRENT COLLAPSE OF SAN JUAN AND UNCOMPAHGRE CALDERAS WITHIN DEPRESSION,

Comment (Geology): AND DEPOSITION OF THICK INTRA-CALDERA TUFFS AND INTERBEDDED LANDSLIDE BRECCIAS OF ITS EUREKA MEMBER; (5) EARLY POSTSUBSIDENCE LOCAL DOMING AND ERUPTION OF VISCOUS, PORPHYRITIC RHYODACITE TO QUARTZ LATITE LAVAS GRADING UPWARD INTO ANDESITE IN SAN JUAN CALDERA, WITH PERIPHERAL DEPOSITION OF BEDDED TUFFS, VOLCANICLASTICS, AND LACUSTRINE SEDIMENTS (BURNS FM); LATER INFILLING PREDOMINANTLY VOLCANICLASTIC SEDIMENTS AND MUDFLOW BRECCIAS (HENSON FM), PARTLY OVERFLOWING SE CALDERA WALL; (6) INFILL SEQUENCE OVERLAIN BY ASH-FLOW TUFFS FROM ADJACENT ERUPTIVE CENTERS--FISH CANYON (LA GARITA CALDERA)(28.5 M.Y.), CRYSTAL LAKE (SILVERTONCALDERA), CARPENTER RIDGE (BACHELOR CALDERA), WASON PARK (SOURCE UNKNOWN), AND NELSON MOUNTAIN (SAN LUIS CALDERA); (7) ERUPTION OF CRYSTAL LAKE TUFF (27.5 M.Y.) RESULTED IN TRAPDOOR COLLAPSE OF SILVERTON CALDERA NESTED WITHIN SAN JUAN CALDERA, WITH GREATEST DISPLACEMENT ON SOUTH MARGIN AND GRABEN-FAULTED MONOCLINE ON NE; PRE- AND POST-COLLAPSE MONZONITIC INTRUSIONS

Comment (Location): PRINCIPAL INTRUSIVE LIES ON WEST SIDE OF LAKE FORK GUNNISON RIVER 3 MILES NORTH OF LAKE CITY. TWO SMALLER PLUGS LIE ON EAST SIDE OF RIVER. INCLUDES LOWER PORTIONS OF LARSON CREEK, SPARLING GULCH, EATON GULCH, INDEPENDENCE GULCH, STONY CUT, BILL HARE GULCH, NOURSE CREEK, HOBO GULCH, AND HIGH BRIDGE GULCH. SECTIONS LISTED INCLUDE THOSE PERIPHERAL TO STOCK THAT ARE TRAVERSED BY RADIAL DIKES (WITHIN LIMIT OF LIPMAN'S (1976) MAPPING). AREA ACCESSIBLE VIA COLORADO RTE 149 SOUTH FROM U.S. RTE 50, BLUE MESA RESERVOIR, AND GATEVIEW, AND NORTH FROM LAKE CITY. ELEV AND LAT-LONG GIVEN ARE FOR APPROX CENTER OF PRINCIPAL INTRUSIVE, HILLTOP NEAR C SEC. 10, T44N, R4W. ; INFO FROM LAND.ST :1977

References

Reference (Deposit): STEVEN, T.A., AND OTHERS, 1977, MINERAL RESOURCES OF STUDY AREAS CONTIGUOUS TO THE UNCOMPAHGRE PRIMITIVE AREA, SAN JUAN MOUNTAINS, SOUTHWESTERN COLO RADO: USGS BULL. 1391-E, P. 36, 83-85, PLS. 1, 3.

Reference (Deposit): WORCESTER, P.G., 1919, MOLYBDENUM INDUSTRY: CGS BULL. 14, P. 67.

Reference (Deposit): LIPMAN, P.W., 1976, GEOLOGIC MAP OF THE LAKE CITY CALDERA AREA, WESTERN SAN JUAN MOUNTAINS, SOUTHWESTERN COLORADO: USGS MAP I-962.

Reference (Deposit): HON, KEN, AND MEHNERT, H.H., 1983, COMPILATION OF REVISED AGES OF VOLCANIC UNITS IN THE SAN JUAN MOUNTAINS, COLORADO--RECALCULATED K-AR AGE DETERMINATIONS USING IUGS CONSTANTS: USGS OPEN-FILE REPT. OFR-83-668.

Reference (Deposit): LIPMAN, P.W., AND OTHERS, 1973, REVISED VOLCANIC HISTORY OF THE SAN JUAN, UNCOMPAHGRE, SILVERTON, AND LAKE CITY CALDERAS IN THE WESTERN SAN JUAN MOUNTAINS: USGS JOUR. RESEARCH, V. 1, NO. 6, P. 627-642.

Reference (Deposit): LIPMAN, P.W., AND OTHERS, 1976, MULTIPLE AGES OF MID-TERTIARY MINERALIZATION AND ALTERATION IN THE WESTERN SAN JUAN MOUNTAINS, COLORADO: ECON. GEOLOGY, V. 71, NO. 3, P. 571-588.

Reference (Deposit): STEVEN, T.A., AND LIPMAN, P.W., 1976, CALDERAS OF THE SAN JUAN VOLCANIC FIELD, SOUTHWESTERN COLORADO: USGS PROF. PAPER 958, P. 10-16.

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