La Bolsa Project

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Mine TypeOpen Pit
StatusInactive / Suspended
  • Silver
  • Gold
Mining Method
  • Truck & Shovel / Loader
Mine Life... Lock
SnapshotLa Bolsa is on care and maintenance and owner is currently not carrying out any activities on it. This property is not considered material to Pan American Silver.


Pan American Silver Corp. 100 % Indirect



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Deposit type

  • Breccia pipe / Stockwork
  • Volcanic hosted
  • Epithermal


The mineralized system at La Bolsa represents a low sulfidation, volcanic hosted, epithermal precious metal deposit.

The gold-silver mineralization at La Bolsa occurs within stockwork and disseminations that are generally located within a low-angle north-south trending structural zone that dips moderately eastward from its exposure along a north-south-trending ridge. Mineralization is in the form of an oxidized blanket that is sub-parallel to topography and dips shallowly below surface from the base of the ridge. Mineralization has been traced for approximately 1,100 meters (3,600 feet) in length and up to 800 meters (2,600 feet) in width with thicknesses that range from 10 to 60 meters (30 to 200 feet). Recent drilling at La Bolsa continues to extend that zone, and the known mineralization remains open both down-dip and along strike.

Most of the precious metals mineralization at La Bolsa occurs within a series of regionally propylitized andesite flows and flow breccias interbedded with varying amounts of conglomerates, arkosic sandstones, and minor siltstone. While the finer sedimentary material is regionally sourced, the coarser conglomeratic clasts are almost exclusively derived from the andesite flows. Andesite flows are moderately porphyritic and can range from less than one meter up to 100 meters thick. Post-depositional faulting and folding as well as the lateral discontinuity of individual beds makes determination of strike and dip difficult. Within this package there is a general transition from sedimentary dominant at the north end of the deposit to volcanic dominant at the south.

While the northwest structural fabric plays a major role at La Bolsa, northeast conjugate sets as well as a range of other orientations possibly associated with emplacement of the intrusives also dissect the area and control mineralization. The main structure and the host to the majority of the mineralization at La Bolsa is the north-northwest trending La Bolsa structure. While moderate to high angle to the northwest, the structure shallows to approximately a 15 to 20 degree east dip at La Bolsa, forming a continuous 10 to 40 meter thick brecciated and fractured zone. Approaching the flow dome the low angle structure forms a series of en-echelon, stair-stepped to the south, flat-lying gashes that eventually die out in the vicinity of the dome.

High-angle structures that cut the low-angle zone are dominantly north–northwest or northeast in orientation although additional subordinate orientations do occur. High-angle structures have at least three observed effects on the low-angle zone and mineralization: 1) select structures acted as mineralizing feeders to the low angle zone; 2) intersection of select high-angle structures and the low-angle zone promoted greater fracturing and brecciation resulting in thicker and higher grade pockets of mineralization; 3) post–mineral structures offset the low- angle mineralized zone. Feeder structures tend to be north–northwest or northeast in orientation and have been identified on the north end of La Bolsa hill and extending to the central portion of the project. Typically these feeder structures have also developed increased fracturing at the intersection. Post- mineral high angle faulting is dominantly west–northwest or east-northeast in orientation with limited offsets of up to several tens of meters.



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Mining Methods


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Crushers and Mills


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Gold oz 227,617
All production numbers are expressed as metal in doré.

Production Costs

Cash costs Gold USD 516 / oz * **  USD
Assumed price Silver USD 14 / oz *  USD
Assumed price Gold USD 850 / oz *  USD
* According to 2011 study / presentation.
** Net of By-Product.

Operating Costs

OP mining costs ($/t milled) USD 7.51 *  USD
Processing costs ($/t milled) USD  ....  Subscribe
G&A ($/t milled) USD  ....  Subscribe
* According to 2011 study.

Project Costs

MetricsUnitsLOM Total
Initial CapEx $M USD  ......  Subscribe
Sustaining CapEx $M USD  ......  Subscribe
Closure costs $M USD  ......  Subscribe
Total CapEx $M USD  ......  Subscribe
OP OpEx $M USD  ......  Subscribe
Processing OpEx $M USD 54.9
G&A costs $M USD 0
Total OpEx $M USD  ......  Subscribe
Gross revenue (LOM) $M USD  ......  Subscribe
Net revenue (LOM) $M USD  ......  Subscribe
Pre-tax Cash Flow (LOM) $M USD  ......  Subscribe
Pre-tax NPV @ 0% $M USD  ......  Subscribe
Pre-tax IRR, %  ......  Subscribe

Heavy Mobile Equipment


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Mine Management

Job TitleNameProfileRef. Date
....................... Subscription required ....................... Subscription required Subscription required Apr 15, 2024

...... Subscription required 2011


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