Mining Intelligence and News

Martha Mine

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Mine TypeOpen Pit & Underground
StatusCare and Maintenance
  • Gold
  • Silver
Mining Method
  • Truck & Shovel / Loader
  • Shrinkage stoping
Production Start... Lock
SnapshotThere was no production at Martha during the year ended December 31, 2022 as the Patagonia Gold did not produce concentrate from Martha after April 2020. Operations at Martha remain on care and maintenance while the Patagonia Gold continues to explore the property.


FOMICRUZ 4.7 % Indirect
Patagonia Gold Plc. 95.3 % Indirect
Patagonia Gold S.A (operator) 100 % Direct

Deposit type

  • Vein / narrow vein
  • Breccia pipe / Stockwork
  • Epithermal


Martha Mineralized Zones
Silver and gold mineralization at Martha is located within a series of quartz-rich, locally banded and brecciated, veins and veinlets. The style of mineralization has been interpreted to be intermediate-sulfidation in character (Paéz et al, 2015 and Sillitoe, 2005). The main trend of the mineralized systems is WNW and EW and dip steeply to moderately to the S, SW. On surface, mineralized structures can be several meters wide but often are much less than a meter in true width but may expand in width in the subsurface.

Base and precious metal-bearing minerals at Martha (Paéz et al, 2015 are galena, sphalerite, chalcopyrite, polybasite [(Ag,Cu)6(Sb,As)2S7][Ag9CuS4], silver-bearing tetrahedrite, pyrargyrite (Ag3SbS3), freieslebenite (AgPbSbS3), acanthite and native silver. Pyrite and arsenopyrite are common. Gold-bearing minerals have not been identified.

Dating of base and precious mineralization is often performed by dating spatially-related minerals. At Martha, Sernageomin (2011), for Paéz’s thesis (Paéz, 2011), dated vein-hosted adularia (a low-temperature variety of orthoclase with the chemical formula KAlSi3O8) at 156.5 mya (million years ago). The host rock was dated at 157.6 mya. Alteration assemblages at Martha have been studied by several workers including the exploration staff at Coeur (Birak et al, 2007) and can be generally grouped into major sets: propylitic, silico-argillic, argillic and silicic. Cedillo Frey (2009) documented the following alteration observations at the Martha Oeste vein, which is situated on strike with, and west of, the Martha vein (translated and paraphrased from original Spanish by the Qualified Person).

“Crystallization of sericite, quartz and adularia occurred from pH neutral, hydrothermal fluids ranging in temperature from 200o to 250 o C. This alteration developed two main zones.
a) An outer zone, extending 1 to 5 meters from the vein with sericite as replacement of potassium feldspar, plagioclase, biotite and phengite (muscovite-like mineral). This alteration increased towards the vein forming muscovite and illite.
b) An Inner zone, extending less than 1 meter from the vein, with massive silicification.
In both zones, adularia can be found but is most abundant in the inner zone.”

Deposit Types
Silver and gold mineralization at Martha, along with lesser amounts of base metals, occurs within quartz rich veins, veinlets, breccias and stockworks. The style of mineralization is interpreted to epithermal in original. Epithermal silver and gold deposits, according to Sillitoe and Hedenquist (2003), occur as “both vein and bulk-tonnage styles may be broadly grouped into high-sulfidation (HS), intermediate-sulfidation (IS), and low-sulfidation (LS) types based on the sulfidation states of their hypogene sulfide assemblages”.   

According to Sillitoe (2005) “The overall characteristics of the Martha veins, in particular the occurrence of bonanza grades in association with massive sulfide bands, the high Ag/Au ratios, and the elevated fluid inclusion salinity values, suggest that the deposit is of intermediate-sulfidation epithermal type, albeit with some low-sulfidation features”.

The precious metal, vein-hosted deposits at Martha tend to occur in two general orientations: WNW and EW striking. The location of the main Martha area veins have been inferred to be located along the S-SW margin of a Jurassic-aged volcanic caldera Martha veins can vary significantly in width, ranging from a few millimeters or centimeters (e.g., the Betty System veins) up to a few meters (e.g., Martha vein). However, what sets the Martha veins apart from other veins systems in the Deseado Massif are their bonanza metal grades which can exceed several thousands of grams of silver per tonne (Paéz et al, 2015) and very high silver to gold ratios.

High-grade silver and gold mineralization can be found in surface exposures but often may only be anomalous on surface; changing in tenor, width and orientation at depth. The longitudinal section of contoured silver grades within the Catalina vein system (part of the Del Medio System) is a good example of how grades and the size of the mineralized zones can change with depth at Martha.



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Mining Methods


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Crushers and Mills

Milling equipment has not been reported.



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Silver oz  ....  Subscribe65,620181,008
Gold Equivalent oz  ....  Subscribe1,008
All production numbers are expressed as metal in concentrate.

Operational metrics

Daily processing capacity  ....  Subscribe  ....  Subscribe240 t

Production Costs

Cash costs Gold Equivalent USD  ....  Subscribe 714 / oz  


Revenue M USD  ....  Subscribe 2.3  
Gross profit M USD  ....  Subscribe 0.7  
Pre-tax Income M USD  ....  Subscribe  ....  Subscribe -0.8  
After-tax Income M USD  ....  Subscribe  ....  Subscribe -1.7  

Heavy Mobile Equipment


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Mine Management

Job TitleNameProfileRef. Date
....................... Subscription required ....................... Subscription required Subscription required Sep 29, 2023

Aerial view:


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