United States

Clayton Valley (Cypress) Project

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Mine TypeOpen Pit
  • Lithium
Mining Method
  • Truck & Shovel / Loader
Mine Life40 years (as of Jan 1, 2020)


Century Lithium Corp. 100 % Indirect
Cypress’ property consists of 5,430 acres (2,197 hectares) of U.S. Federal mining claims. The claims are held 100% by Cypress and subject to an underlying net smelter return (NSR) agreement.



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Deposit type

  • Sedimentary


The western portion of the project area is dominated by the uplifted basement rocks of Angel Island which consist of metavolcanic and clastic rocks, and colluvium. The southern and eastern portions are dominated by uplifted, lacustrine sedimentary units of the Esmeralda Formation. Locally the Esmeralda Formation is comprised of fine grained sedimentary and tuffaceous units, with some occasionally pronounced local undulation and minor faulting. The resulting topography consists of elongate, rounded ridges of exposed Esmeralda Formation separated by washes and gullies filled with alluvial cobble, gravel and fine sediment. The ridge tops are commonly mantled weathered fragments of rock (desert pavement) sourced from the surrounding highlands. Cypress provides the following description of the stratigraphic units of the Esmeralda Formation in the project area, which form a laterally and vertically continuous stratigraphic section which underlies the south and eastern portions of the project area.

Elevated lithium concentrations, generally > 600 ppm, are encountered in the local sedimentary units of the Esmeralda Formation from surface to at least 142 meters below surface grade (bsg). The lithium-bearing sediments primarily occur as silica-rich, moderately calcareous, interbedded tuffaceous mudstone, claystone and siltstone. The overall mineralized sedimentary suite is a laterally and vertically extensive, roughly tabular zone with at least two prominent oxidation horizons. The primary area of mineralization is in a claystone unit consisting of three zones: oxidized claystone, unaltered claystone and an oxidized claystone. The claystone unit is overlain by tuffaceous mudstone in the eastern portion of the project and underlain by a siltstone. Elevated lithium concentrations occur in all the uplifted lacustrine strata encountered; however, lithium concentrations are notably higher and more consistent in the claystone unit.

The deposit type is represented by the USGS deposit model. The model consists of light-colored, ash-rich, lacustrine rocks that contain swelling clays and occur within hydrologically closed basins proximal to silicic volcanic rocks. The geometry of the deposit at the project is roughly tabular, with the lithium concentrated in gently dipping, locally undulating, sedimentary strata of the Esmeralda Formation. The sedimentary units are interbedded silica-rich, ash-rich mudstone and claystone, with interbeds of sandy and tuffaceous mudstone/siltstone and occasional poorly cemented silt and sandstone. The lithium concentrations are highest within the mudstone and claystone, but lithium is still present in a siltstone unit underlying the claystone.

The deposition of the lithium-rich sediments likely occurred late in the history of the associated paleo brine lake, based largely on the stratigraphic position of the mudstone and claystone above the thick overall sandstone- and siltstone-dominated basin fill events. Such a setting would be ideal for concentration of lithium from ash and groundwater inputs over an extensive period.



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Mining Methods


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Crushers and Mills


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CommodityUnitsDailyAvg. Annual
LCE t 0027,400

Operational metrics

Daily ore mining rate 00000
Daily processing rate 00000
Annual production capacity 000000
Annual processing rate 0000
Stripping / waste ratio 000
Waste tonnes, LOM 000
Ore tonnes mined, LOM 00000
Tonnes processed, LOM 000
* According to 2020 study.

Production Costs

Cash costs LCE USD 0000
Assumed price LCE USD 0000
* According to 2020 study / presentation.

Operating Costs

OP mining costs ($/t milled) USD 1.83 *  
Processing costs ($/t milled) USD  ....  Subscribe
G&A ($/t milled) USD  ....  Subscribe
Total operating costs ($/t milled) USD  ....  Subscribe
* According to 2020 study.

Project Costs

MetricsUnitsLOM Total
Initial CapEx  ......  Subscribe
After-tax NPV @ 8%  ......  Subscribe
After-tax IRR, %  ......  Subscribe
After-tax payback period, years  ......  Subscribe

Heavy Mobile Equipment


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Mine Management

Source Source
Job TitleNameProfileRef. Date
....................... Subscription required ....................... Subscription required Subscription required May 19, 2020
....................... Subscription required ....................... Subscription required Subscription required Jan 4, 2024
....................... Subscription required ....................... Subscription required Subscription required Jan 4, 2024
....................... Subscription required ....................... Subscription required Subscription required Jan 4, 2024

Total WorkforceYear
Subscription required 2020


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