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Laramie Formation, Golden, Golden Mining District, Jefferson County, Colorado, USAi
| Regional Level Types | |
|---|---|
| Laramie Formation | Formation |
| Golden | City |
| Golden Mining District | Mining District |
| Jefferson County | County |
| Colorado | State |
| USA | Country |
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Latitude & Longitude (WGS84):
39° 45' 4'' North , 105° 13' 32'' West
Latitude & Longitude (decimal):
Type:
Köppen climate type:
In the Golden area the Late Cretaceous Laramie Formation outcrops all along and just east of the abrupt beginning of the Rocky Mountains. The Laramie is well exposed from the mouth of Clear Creek Canyon southward and was the sight of numerous clay pits. These clay pits ran parallel to the east side of Rt. 6 for a considerable distance. Some, south of town, were worked by into at least the 1970's.
Because of the nearby Golden fault the beds of the Laramie Formation in the Golden area stood vertically or even slightly over turned. Many of the pits were a series of deep parallel cuts, which marked the mined out clay-rich beds. The intervening sandy beds were left standing. The Laramie formation was better known for fossils palm leaves than for minerals. Parts of the last working pits, just south of Golden, are now incorporated into a golf course fittingly called "Fossil Trace".
In the Golden area the lower 200 feet of the Laramie Formation contains several subbituminous coal seams. The thickness of the seams is quite variable along strike. Exposure of these seams is very poor. In the late 19th and early 20th centuries there were several small coal mines in and near Golden. However, the bulk of coal production in the local area, 80+%, came from the Leyden Mine several miles north of town. In recent years these former mines have received attention because of potential subsidense in an urbanizing area. The Laramie Formation coals, as well as those of the overlying Denver Formation, have also been viewed as possible sources of coal bed methane.
The Laramie Formation is a transitional unit deposited in a low coastal plain environment just after the withdrawal of the Cretaceous seaway. In an outcrop near the edge of the Colorado School of Mines campus there is a bed of conglomerate, the first indication of the rise of the Rocky Mountains to the west.
Select Mineral List Type
Standard Detailed Gallery Strunz Chemical ElementsDetailed Mineral List:
| ⓘ Kaolinite Formula: Al2(Si2O5)(OH)4 |
| ⓘ Montmorillonite Formula: (Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2 · nH2O |
| ⓘ Muscovite Formula: KAl2(AlSi3O10)(OH)2 References: |
| ⓘ Muscovite var. Illite Formula: K0.65Al2.0[Al0.65Si3.35O10](OH)2 |
Gallery:
List of minerals arranged by Strunz 10th Edition classification
| Group 9 - Silicates | |||
|---|---|---|---|
| ⓘ | Muscovite var. Illite | 9.EC.15 | K0.65Al2.0[Al0.65Si3.35O10](OH)2 |
| ⓘ | 9.EC.15 | KAl2(AlSi3O10)(OH)2 | |
| ⓘ | Montmorillonite | 9.EC.40 | (Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2 · nH2O |
| ⓘ | Kaolinite | 9.ED.05 | Al2(Si2O5)(OH)4 |
List of minerals for each chemical element
| H | Hydrogen | |
|---|---|---|
| H | ⓘ Muscovite var. Illite | K0.65Al2.0[Al0.65Si3.35O10](OH)2 |
| H | ⓘ Kaolinite | Al2(Si2O5)(OH)4 |
| H | ⓘ Muscovite | KAl2(AlSi3O10)(OH)2 |
| H | ⓘ Montmorillonite | (Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2 · nH2O |
| O | Oxygen | |
| O | ⓘ Muscovite var. Illite | K0.65Al2.0[Al0.65Si3.35O10](OH)2 |
| O | ⓘ Kaolinite | Al2(Si2O5)(OH)4 |
| O | ⓘ Muscovite | KAl2(AlSi3O10)(OH)2 |
| O | ⓘ Montmorillonite | (Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2 · nH2O |
| Na | Sodium | |
| Na | ⓘ Montmorillonite | (Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2 · nH2O |
| Mg | Magnesium | |
| Mg | ⓘ Montmorillonite | (Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2 · nH2O |
| Al | Aluminium | |
| Al | ⓘ Muscovite var. Illite | K0.65Al2.0[Al0.65Si3.35O10](OH)2 |
| Al | ⓘ Kaolinite | Al2(Si2O5)(OH)4 |
| Al | ⓘ Muscovite | KAl2(AlSi3O10)(OH)2 |
| Al | ⓘ Montmorillonite | (Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2 · nH2O |
| Si | Silicon | |
| Si | ⓘ Muscovite var. Illite | K0.65Al2.0[Al0.65Si3.35O10](OH)2 |
| Si | ⓘ Kaolinite | Al2(Si2O5)(OH)4 |
| Si | ⓘ Muscovite | KAl2(AlSi3O10)(OH)2 |
| Si | ⓘ Montmorillonite | (Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2 · nH2O |
| K | Potassium | |
| K | ⓘ Muscovite var. Illite | K0.65Al2.0[Al0.65Si3.35O10](OH)2 |
| K | ⓘ Muscovite | KAl2(AlSi3O10)(OH)2 |
| Ca | Calcium | |
| Ca | ⓘ Montmorillonite | (Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2 · nH2O |
Other Regions, Features and Areas containing this locality
North AmericaContinent
- Rocky MountainsMountain Range
North America PlateTectonic Plate
- Great Plains DomainDomain
- Southern Rocky MountainsOrogenic Belt
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