Cebolla Mining District (Goose Creek Mining District), Gunnison County, Colorado, USAi
Regional Level Types | |
---|---|
Cebolla Mining District (Goose Creek Mining District) | Mining District |
Gunnison County | County |
Colorado | State |
USA | Country |
This page is currently not sponsored. Click here to sponsor this page.
Latitude & Longitude (WGS84):
38° North , 107° West (est.)
Estimate based on other nearby localities or region boundaries.
Margin of Error:
~75km
Locality type:
Köppen climate type:
General Geology.
The Cebolla district lies on the north flank of the San Juan Mountains south of the Gunnison River. It is characterized by dissected mesas sloping toward the Gunnison River at an altitude of about 8,500 to 9,000 feet. The pre-Cambrian basement rocks are capped by erosion remnants of the Alboroto rhyolite and latitic breccias of the San Juan Mountain volcanic rocks. Beneath the volcanic capping there are a few thin remnants of Jurassic sedimentary rocks bordering the Gunnison River. The early Tertiary erosion surface on which the volcanic rocks rest and the late Paleozoic or early Mesozoic surface on which the Jurassic rocks rest are closely coincident. This is of possible significance with regard to cycles of erosion and leaching to which the vein deposits have been subjected.
The pre-Cambrian rocks are exposed over large areas between the dissected mesas and in the canyons of the principal streams, the Lake Fork Gunnison River, and Cebolla Creek. They consist of chlorite, mica, and hornblende schists and greenstones, which are intruded by granitic and syenitic rocks and cut by pegmatite dikes and younger volcanic rocks. The granitic and pegmatitic rocks are of pre-Cambrian age, but some dikes and other intrusive rocks may be younger.
Vein Deposits.
Two types of vein deposits occur in the Cebolla area besides the pegmatite dikes. They are capped unconformably by Jurassic sedimentary rocks and Tertiary volcanic rocks. The oldest veins are quartz-chlorite and contain copper and gold like those of the Cochetopa area. These are generally nonradioactive although a few minor exceptions were noted. The principal radioactive deposits are quartz-carbonate veins containing minor amounts of pyrite, sphalerite, and galena. Locally the deposits were prospected for silver. The quartz in many veins is typically smoky and crackled and is associated with a gray carbonate gangue of dolomitic or ankeritic aspect. The sulfides and radioactive materials are intergrown with these gangues in exposures of the veins along the valley and canyon walls. On the mesa surfaces the veins are locally much altered to a vericolored jaspery material, which has chiefly replaced the carbonate gangue. The jaspery material retains some of the radioactivity of the original vein matter. The veins are locally jasperized to depths of 50 to 100 feet beneath the volcanic capping of the mesas. Jasperization was also prevolcanic and presumably related to older Mesozoic or late Paleozoic erosion surfaces. It may be partly related to hot-spring activity.
Exposures of the veins in the canyons and dissected mesas through a vertical range of 800 to 1,000 feet show that oxidation extended locally to depths of several hundred feet, depending upon local relief and ground-water conditions. Leaching and dispersion of the radioactive material could have taken place during several cycles of erosion since Paleozoic time.
The greater part of the present radioactivity is due to the thorium content of the veins, but conceivably some uranium could have been leached from the veins near the different erosion surfaces. Deposition of postmine radioactive carbonate stalactites indicates that some leaching of uranium disintegration products is still in progress. Further chemical research is desirable to form a basis for judging the significance of these occurrences.
The veins are not of economic value at present, but,should appreciable leaching of uranium become established, further testing by deep drilling would be desirable.
The Cebolla district lies on the north flank of the San Juan Mountains south of the Gunnison River. It is characterized by dissected mesas sloping toward the Gunnison River at an altitude of about 8,500 to 9,000 feet. The pre-Cambrian basement rocks are capped by erosion remnants of the Alboroto rhyolite and latitic breccias of the San Juan Mountain volcanic rocks. Beneath the volcanic capping there are a few thin remnants of Jurassic sedimentary rocks bordering the Gunnison River. The early Tertiary erosion surface on which the volcanic rocks rest and the late Paleozoic or early Mesozoic surface on which the Jurassic rocks rest are closely coincident. This is of possible significance with regard to cycles of erosion and leaching to which the vein deposits have been subjected.
The pre-Cambrian rocks are exposed over large areas between the dissected mesas and in the canyons of the principal streams, the Lake Fork Gunnison River, and Cebolla Creek. They consist of chlorite, mica, and hornblende schists and greenstones, which are intruded by granitic and syenitic rocks and cut by pegmatite dikes and younger volcanic rocks. The granitic and pegmatitic rocks are of pre-Cambrian age, but some dikes and other intrusive rocks may be younger.
Vein Deposits.
Two types of vein deposits occur in the Cebolla area besides the pegmatite dikes. They are capped unconformably by Jurassic sedimentary rocks and Tertiary volcanic rocks. The oldest veins are quartz-chlorite and contain copper and gold like those of the Cochetopa area. These are generally nonradioactive although a few minor exceptions were noted. The principal radioactive deposits are quartz-carbonate veins containing minor amounts of pyrite, sphalerite, and galena. Locally the deposits were prospected for silver. The quartz in many veins is typically smoky and crackled and is associated with a gray carbonate gangue of dolomitic or ankeritic aspect. The sulfides and radioactive materials are intergrown with these gangues in exposures of the veins along the valley and canyon walls. On the mesa surfaces the veins are locally much altered to a vericolored jaspery material, which has chiefly replaced the carbonate gangue. The jaspery material retains some of the radioactivity of the original vein matter. The veins are locally jasperized to depths of 50 to 100 feet beneath the volcanic capping of the mesas. Jasperization was also prevolcanic and presumably related to older Mesozoic or late Paleozoic erosion surfaces. It may be partly related to hot-spring activity.
Exposures of the veins in the canyons and dissected mesas through a vertical range of 800 to 1,000 feet show that oxidation extended locally to depths of several hundred feet, depending upon local relief and ground-water conditions. Leaching and dispersion of the radioactive material could have taken place during several cycles of erosion since Paleozoic time.
The greater part of the present radioactivity is due to the thorium content of the veins, but conceivably some uranium could have been leached from the veins near the different erosion surfaces. Deposition of postmine radioactive carbonate stalactites indicates that some leaching of uranium disintegration products is still in progress. Further chemical research is desirable to form a basis for judging the significance of these occurrences.
The veins are not of economic value at present, but,should appreciable leaching of uranium become established, further testing by deep drilling would be desirable.
Select Mineral List Type
Standard Detailed Gallery Strunz Chemical ElementsCommodity List
This is a list of exploitable or exploited mineral commodities recorded from this region.Mineral List
Mineral list contains entries from the region specified including sub-localities14 valid minerals.
Rock Types Recorded
Note: data is currently VERY limited. Please bear with us while we work towards adding this information!
Rock list contains entries from the region specified including sub-localities
Select Rock List Type
Alphabetical List Tree DiagramDetailed Mineral List:
ⓘ Anatase Formula: TiO2 Localities: Reference: MacFall, P.M. (1951) Gem Hunter's Guide (1st ed.). Science and Mathematics Publishing Company, 187 pages.; The Mineralogical Record, volumbe 25/5, pp. 371-374 |
ⓘ Brookite Formula: TiO2 Reference: R. Peter Richards; The Mineralogical Record, volumbe 25/5, pp. 371-374 |
ⓘ Calcite Formula: CaCO3 Locality: Lot mine, Cebolla Mining District (Goose Creek Mining District), Gunnison County, Colorado, USA Reference: U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia. |
ⓘ Chalcopyrite Formula: CuFeS2 Locality: Lot mine, Cebolla Mining District (Goose Creek Mining District), Gunnison County, Colorado, USA Reference: U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia. |
ⓘ 'Chlorite Group' Reference: Burbank, W. S., Pierson, C. T. (1953) Preliminary Results of Radiometric Reconnaissance of Parts of the Northwestern San Juan Mountains, Colorado, USGS Circular 236, 2-3. |
ⓘ Epidote Formula: {Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH) Localities: Reference: U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia. |
ⓘ Galena Formula: PbS Localities: Reference: U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia. |
ⓘ 'Garnet Group' Formula: X3Z2(SiO4)3 Locality: Lot mine, Cebolla Mining District (Goose Creek Mining District), Gunnison County, Colorado, USA Reference: U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia. |
ⓘ Hematite Formula: Fe2O3 Reference: Minerals of Colorado (1997) Eckel, E. B. |
ⓘ 'Hornblende' Reference: Minerals of Colorado (1997) E.B. Eckel |
ⓘ 'Limonite' Localities: Reference: U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia. |
ⓘ Magnetite Formula: Fe2+Fe3+2O4 Localities: Reference: U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia. |
ⓘ 'Psilomelane' Reference: Minerals of Colorado (1997) E.B. Eckel |
ⓘ Pyrite Formula: FeS2 Localities: Reference: U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia. |
ⓘ Pyrolusite Formula: Mn4+O2 Reference: Minerals of Colorado (1997) E.B. Eckel |
ⓘ Quartz Formula: SiO2 Localities: Reference: U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia. |
ⓘ Quartz var. Jasper Reference: Burbank, W. S., Pierson, C. T. (1953) Preliminary Results of Radiometric Reconnaissance of Parts of the Northwestern San Juan Mountains, Colorado, USGS Circular 236, 2-3. |
ⓘ 'Rhombohedral Carbonate' Formula: (Ca/Mg/Fe/Mn etc)CO3 Reference: Burbank, W. S., Pierson, C. T. (1953) Preliminary Results of Radiometric Reconnaissance of Parts of the Northwestern San Juan Mountains, Colorado, USGS Circular 236, 2-3. |
ⓘ Siderite Formula: FeCO3 Reference: Minerals of Colorado (1997) Eckel, E. B. |
ⓘ Sphalerite Formula: ZnS Localities: Reference: U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia. |
ⓘ Zoisite Formula: Ca2Al3[Si2O7][SiO4]O(OH) Reference: Minerals of Colorado (1997) E.B. Eckel |
List of minerals arranged by Strunz 10th Edition classification
Group 2 - Sulphides and Sulfosalts | |||
---|---|---|---|
ⓘ | Chalcopyrite | 2.CB.10a | CuFeS2 |
ⓘ | Galena | 2.CD.10 | PbS |
ⓘ | Pyrite | 2.EB.05a | FeS2 |
ⓘ | Sphalerite | 2.CB.05a | ZnS |
Group 4 - Oxides and Hydroxides | |||
ⓘ | Anatase | 4.DD.05 | TiO2 |
ⓘ | Brookite | 4.DD.10 | TiO2 |
ⓘ | Hematite | 4.CB.05 | Fe2O3 |
ⓘ | Magnetite | 4.BB.05 | Fe2+Fe3+2O4 |
ⓘ | Pyrolusite | 4.DB.05 | Mn4+O2 |
ⓘ | Quartz | 4.DA.05 | SiO2 |
ⓘ | var. Jasper | 4.DA.05 | SiO2 |
Group 5 - Nitrates and Carbonates | |||
ⓘ | Calcite | 5.AB.05 | CaCO3 |
ⓘ | Siderite | 5.AB.05 | FeCO3 |
Group 9 - Silicates | |||
ⓘ | Epidote | 9.BG.05a | {Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH) |
ⓘ | Zoisite | 9.BG.10 | Ca2Al3[Si2O7][SiO4]O(OH) |
Unclassified Minerals, Rocks, etc. | |||
ⓘ | 'Chlorite Group' | - | |
ⓘ | 'Garnet Group' | - | X3Z2(SiO4)3 |
ⓘ | 'Hornblende' | - | |
ⓘ | 'Limonite' | - | |
ⓘ | 'Psilomelane' | - | |
ⓘ | 'Rhombohedral Carbonate' | - | (Ca/Mg/Fe/Mn etc)CO3 |
List of minerals for each chemical element
H | Hydrogen | |
---|---|---|
H | ⓘ Epidote | {Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH) |
H | ⓘ Zoisite | Ca2Al3[Si2O7][SiO4]O(OH) |
C | Carbon | |
C | ⓘ Calcite | CaCO3 |
C | ⓘ Siderite | FeCO3 |
C | ⓘ Rhombohedral Carbonate | (Ca/Mg/Fe/Mn etc)CO3 |
O | Oxygen | |
O | ⓘ Brookite | TiO2 |
O | ⓘ Anatase | TiO2 |
O | ⓘ Quartz | SiO2 |
O | ⓘ Calcite | CaCO3 |
O | ⓘ Epidote | {Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH) |
O | ⓘ Magnetite | Fe2+Fe23+O4 |
O | ⓘ Garnet Group | X3Z2(SiO4)3 |
O | ⓘ Hematite | Fe2O3 |
O | ⓘ Siderite | FeCO3 |
O | ⓘ Pyrolusite | Mn4+O2 |
O | ⓘ Zoisite | Ca2Al3[Si2O7][SiO4]O(OH) |
O | ⓘ Rhombohedral Carbonate | (Ca/Mg/Fe/Mn etc)CO3 |
Mg | Magnesium | |
Mg | ⓘ Rhombohedral Carbonate | (Ca/Mg/Fe/Mn etc)CO3 |
Al | Aluminium | |
Al | ⓘ Epidote | {Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH) |
Al | ⓘ Zoisite | Ca2Al3[Si2O7][SiO4]O(OH) |
Si | Silicon | |
Si | ⓘ Quartz | SiO2 |
Si | ⓘ Epidote | {Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH) |
Si | ⓘ Garnet Group | X3Z2(SiO4)3 |
Si | ⓘ Zoisite | Ca2Al3[Si2O7][SiO4]O(OH) |
S | Sulfur | |
S | ⓘ Sphalerite | ZnS |
S | ⓘ Pyrite | FeS2 |
S | ⓘ Chalcopyrite | CuFeS2 |
S | ⓘ Galena | PbS |
Ca | Calcium | |
Ca | ⓘ Calcite | CaCO3 |
Ca | ⓘ Epidote | {Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH) |
Ca | ⓘ Zoisite | Ca2Al3[Si2O7][SiO4]O(OH) |
Ca | ⓘ Rhombohedral Carbonate | (Ca/Mg/Fe/Mn etc)CO3 |
Ti | Titanium | |
Ti | ⓘ Brookite | TiO2 |
Ti | ⓘ Anatase | TiO2 |
Mn | Manganese | |
Mn | ⓘ Pyrolusite | Mn4+O2 |
Mn | ⓘ Rhombohedral Carbonate | (Ca/Mg/Fe/Mn etc)CO3 |
Fe | Iron | |
Fe | ⓘ Pyrite | FeS2 |
Fe | ⓘ Chalcopyrite | CuFeS2 |
Fe | ⓘ Epidote | {Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH) |
Fe | ⓘ Magnetite | Fe2+Fe23+O4 |
Fe | ⓘ Hematite | Fe2O3 |
Fe | ⓘ Siderite | FeCO3 |
Fe | ⓘ Rhombohedral Carbonate | (Ca/Mg/Fe/Mn etc)CO3 |
Cu | Copper | |
Cu | ⓘ Chalcopyrite | CuFeS2 |
Zn | Zinc | |
Zn | ⓘ Sphalerite | ZnS |
Pb | Lead | |
Pb | ⓘ Galena | PbS |
References
Sort by
Year (asc) Year (desc) Author (A-Z) Author (Z-A) In-text Citation No.Burbank, W. S., Pierson, C. T. (1953) Preliminary Results of Radiometric Reconnaissance of Parts of the Northwestern San Juan Mountains, Colorado, USGS Circular 236, 2-3.
Localities in this Region
- Colorado
- Gunnison County
- Cebolla Mining District (Goose Creek Mining District)
- Gunnison County
Other Regions, Features and Areas containing this locality
North America
- Rocky MountainsMountain Range
North America PlateTectonic Plate
- Great Plains DomainDomain
USA
- Green River FormationFormation
This page contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to
visit any sites listed in mindat.org without first ensuring that you have the permission of the land and/or mineral rights holders
for access and that you are aware of all safety precautions necessary.
Anatase locality, Lot mine, Cebolla Mining District, Gunnison County, Colorado, USA