Crest deposit, Snake River, Mayo mining district, Yukon, Canadai
| Regional Level Types | |
|---|---|
| Crest deposit | Deposit |
| Snake River | River |
| Mayo mining district | Mining District |
| Yukon | Territory |
| Canada | Country |
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Latitude & Longitude (WGS84):
65° 15' 7'' North , 133° 2' 21'' West
Latitude & Longitude (decimal):
Type:
KΓΆppen climate type:
Mindat Locality ID:
195364
Long-form identifier:
mindat:1:2:195364:3
GUID (UUID V4):
aa483e06-4c80-4d22-a762-eeecbf5241b3
Work History
Hematite float in glacial till was well known for years (Geological Survey of Canada Paper 50-14) before the source was discovered by California Standard Company Ltd in 1961. A total of 862 claims (an area of about 240 sq km) were staked in Jun/62 and transferred to a new subsidiary company, Crest Exploration Ltd, which carried out geological mapping, channel sampling, ground and airborne geophysical surveying and drilled one hole (106.7 m) in 1962. In 1963 the company continued channel sampling, carried out bulk sampling, drilled 18 holes (2,549.3 m) and constructed an airstrip.
In addition, the entire property was surveyed and taken to lease and a feasibility study was carried out by Canadian Bechtel Ltd in 1963-64, and two bulk samples totaling about 110 tonnes were shipped out for metallurgical tests. Sometime in the late 1970's to early 1980's the property was transferred to Chevron Resources Canada.
In Apr/2002 Promithian Inc, the Nacho Nyak Dun Development Corporation and the Yukon Department of Energy Mines and Resources engaged Hatch Associates Ltd to carry out a high level evaluation of Promithian's plan for developing the Crest Iron deposit into a mining-steel manufacturing operation. In Jul/2006 Chevron Resources Canada Ltd commissioned Hatch Consulting Ltd to review the economics of the Crest Iron deposit.
Capsule Geology
Iron formation composed of unaltered hematite and jasper occurs near the base of the glacial-marine Rapitan Formation of Late Proterozoic age. Thickness is up to 152 m and average iron content is 43% and ranges as high as 65%. Thin layers with primary sedimentary features suggest that chemical deposition of alternating silica and hematite rich layers was interrupted by the influx of flows of conglomerate and mud, which scoured channels in the soft iron and silica sediment. Some of the fine grained clastic beds impregnated with hematite have the appearance of tuff or volcanic ash that settled in soft hematitic ooze.
The hematite and silica are believed to have been carried in solution by fumarolic waters and precipitated in grabens on the sea floor. Phosphorous is the main impurity, occurring as finely disseminated apatite.
In May/64 mineable reserves in the Iron Creek area (zones 1 to 9), employing a less than 1:1 stripping ratio, were estimated at 3,175,147,000 tonnes, averaging 43.8% iron, 26.6% silica and 0.34% phosphorous. In 1986 Yeo published a reserve figure of 5.6 billion tonnes averaging 47.2% iron for the central part of the Crest deposit. Regional reserves are estimated at over 18.5 billion tonnes.
Hematite float in glacial till was well known for years (Geological Survey of Canada Paper 50-14) before the source was discovered by California Standard Company Ltd in 1961. A total of 862 claims (an area of about 240 sq km) were staked in Jun/62 and transferred to a new subsidiary company, Crest Exploration Ltd, which carried out geological mapping, channel sampling, ground and airborne geophysical surveying and drilled one hole (106.7 m) in 1962. In 1963 the company continued channel sampling, carried out bulk sampling, drilled 18 holes (2,549.3 m) and constructed an airstrip.
In addition, the entire property was surveyed and taken to lease and a feasibility study was carried out by Canadian Bechtel Ltd in 1963-64, and two bulk samples totaling about 110 tonnes were shipped out for metallurgical tests. Sometime in the late 1970's to early 1980's the property was transferred to Chevron Resources Canada.
In Apr/2002 Promithian Inc, the Nacho Nyak Dun Development Corporation and the Yukon Department of Energy Mines and Resources engaged Hatch Associates Ltd to carry out a high level evaluation of Promithian's plan for developing the Crest Iron deposit into a mining-steel manufacturing operation. In Jul/2006 Chevron Resources Canada Ltd commissioned Hatch Consulting Ltd to review the economics of the Crest Iron deposit.
Capsule Geology
Iron formation composed of unaltered hematite and jasper occurs near the base of the glacial-marine Rapitan Formation of Late Proterozoic age. Thickness is up to 152 m and average iron content is 43% and ranges as high as 65%. Thin layers with primary sedimentary features suggest that chemical deposition of alternating silica and hematite rich layers was interrupted by the influx of flows of conglomerate and mud, which scoured channels in the soft iron and silica sediment. Some of the fine grained clastic beds impregnated with hematite have the appearance of tuff or volcanic ash that settled in soft hematitic ooze.
The hematite and silica are believed to have been carried in solution by fumarolic waters and precipitated in grabens on the sea floor. Phosphorous is the main impurity, occurring as finely disseminated apatite.
In May/64 mineable reserves in the Iron Creek area (zones 1 to 9), employing a less than 1:1 stripping ratio, were estimated at 3,175,147,000 tonnes, averaging 43.8% iron, 26.6% silica and 0.34% phosphorous. In 1986 Yeo published a reserve figure of 5.6 billion tonnes averaging 47.2% iron for the central part of the Crest deposit. Regional reserves are estimated at over 18.5 billion tonnes.
Select Mineral List Type
Standard Detailed Gallery Strunz Chemical ElementsDetailed Mineral List:
| β Calcite Formula: CaCO3 References: |
| β Hematite Formula: Fe2O3 References: |
| β Hematite var. Specularite Formula: Fe2O3 References: |
| β 'Jasper' References: |
| β Quartz Formula: SiO2 References: |
Gallery:
List of minerals arranged by Strunz 10th Edition classification
| Group 4 - Oxides and Hydroxides | |||
|---|---|---|---|
| β | Hematite | 4.CB.05 | Fe2O3 |
| β | var. Specularite | 4.CB.05 | Fe2O3 |
| β | Quartz | 4.DA.05 | SiO2 |
| Group 5 - Nitrates and Carbonates | |||
| β | Calcite | 5.AB.05 | CaCO3 |
| Unclassified | |||
| β | 'Jasper' | - | |
List of minerals for each chemical element
| C | Carbon | |
|---|---|---|
| C | β Calcite | CaCO3 |
| O | Oxygen | |
| O | β Calcite | CaCO3 |
| O | β Hematite | Fe2O3 |
| O | β Quartz | SiO2 |
| O | β Hematite var. Specularite | Fe2O3 |
| Si | Silicon | |
| Si | β Quartz | SiO2 |
| Ca | Calcium | |
| Ca | β Calcite | CaCO3 |
| Fe | Iron | |
| Fe | β Hematite | Fe2O3 |
| Fe | β Hematite var. Specularite | Fe2O3 |
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References
