(Gold-Silver Intermediate to Low Sulphidation Ore Deposit)
The Suriloma property is located in the Department of La Libertad in Peru, 60 Km northeast of the city of Trujillo (Fig. 1). The project is located between 3200-3900 metres in elevation. The property lies within a mineral belt containing several world-class gold deposits. Suriloma is 30 Km west of Barrick’s Lagunas Norte mine (2011 production: 763,000 Oz gold) and 50 Km west of Rio Alto’s La Arena gold mine (2012 production: 212,000 Oz gold – Rio Alto Mining website, 2013). The Shahuindo gold-silver deposit in the Department of Cajamarca is located 50 Km to the north (4M Oz gold endowment: Sulliden Gold Corporation, 2012). The huge Yanacocha gold deposit (70M Oz gold endowment: Teal and Benavides, 2010) lies 100 Km to the north.
The Suriloma Project is composed by two mining concessions Santa Felicita 2 of 657 hectares (code: 630006209) and Surupampa III 2009 of 800 hectares (code: 630006809); see Fig. 2
In 2012 a company called Darwin Resources Corp. (Darwin) acquired the Suriloma mineral concessions, this company carried out a surface exploration program consisting in mapping and rock geochemistry to identify mineralized targets. The result of this program generated several targets for future drilling but the area never was drilled. Conclusions at the end of the exploration indicated that Suriloma corresponds to an intermediate to low sulphidation gold-silver epithermal to mesothermal vein system (ore deposit).
No Mineral Resource or Mineral Reserve is known. Two styles of mineralization occur on the property: (a) Stockwork gold mineralization; and (b) Quartz vein silver - gold - base metal mineralization; mineralization is hosted by the Calipuy Group volcanic rocks of mid-Tertiary age, and Goyllarisquizga Group quartz sandstones of Cretaceous age (Fig. 3). The mineralization occurs over a discontinuous strike length of 7 kilometres, and over a vertical interval of some 700 metres between 3,200 metres and 3,900 metres above sea level (elevation).
Old artisanal mine workings for silver and antimony veins are present in the area. At least Seven target areas for gold and silver mineralization have been identified at Suriloma. Darwin has collected around 650 surface samples (rock geochemistry), most of which are continuous channel samples averaging 2m in length.
Darwin´s report (NI 43-101) indicates rock geochemistry for gold and silver (Figs. 4 and 5) and also for other elements. The La Puerta target is the principal gold oxide target hosted by epithermal quartz stockwork mineralization within andesite host rocks associated with argillic (illite ± smectite) alteration. A total of 309 channel samples were collected and assayed from 24 channels dug perpendicular to the strike of the gold structure over a 1 Km length. An epithermal gold stockwork zone has been identified in two sub-parallel mineralized zones with a combined width of up to 60 metres. Highlights of the channel sampling from the La Puerta area include 29 metres @ 1.6g/t gold + 4.5g/t silver, 26 metres @ 1.28g/t gold + 0.5g/t silver, and 16 metres @ 2.2g/t gold + 2g/t silver. The average grade of all 309 channel samples, including unmineralized samples, is 0.90g/t gold (ranging from <0.005 to 12.8 g/t Au) and 15 g/t silver (ranging from <0.2 to 171 g/t Ag). Nine samples are anomalous in arsenic, and there is a strong positive correlation between gold and arsenic. Base metal values in the stockwork are low. Gold mineralization is related to the density of quartz stockwork veinlets, and is disseminated in the hydrothermally altered rocks. The stockwork mineralization is believed to have formed at around 160 to 200 °C in a shallow epithermal environment based on the clay mineralogy. Outcrops of the stockwork are now oxidised containing no sulfide. The western end of the mineralized structure at La Puerta is interpreted to lie beneath shallow post-mineral volcanic cover. The stockwork mineralization at the La Puerta target has the potential to host a large tonnage, low grade, oxide gold deposit. The initial conceptual target has a strike length of 1,000 metres, a depth potential of 200 metres (i.e., to the base of the mineralized volcanic unit) and width of 50+ metres.
Potential exists for the gold mineralization to extend into the Mesozoic sediments that underlie the volcanic host rocks. Other gold stockwork targets at Suriloma include the Inmaculada and Santa Felicita areas. At Santa Felicita gold mineralization is hosted in quartz sandstones, with reconnaissance samples grading up to 4.4 g/t gold in hydrothermal breccia. Further work is required to define the exploration potential at these areas explained by Darwin. Quartz sandstones are the host of major gold deposits in the La Libertad region of Peru, including Lagunas Norte and La Arena, so these targets warrant further work.
Darwin also reports a metallurgical cyanide leach test of representative material from surface samples at La Puerta grading 1.48g/t gold returned a gold recovery of 90.7% gold from a cyanide bottle roll test within a 24 hour period, with cyanide consumption of 0.4 kg/t. This was a highly favourable result, indicating the vast majority of gold mineralization in surface outcrops is easily leachable with low cyanide consumption. It is noted that this was a preliminary metallurgical test from surface mineralization, and is not necessarily representative of mineralization in the sub-surface. Further metallurgical testing is recommended once drill cores will be available.
Darwin´s report shows that silver - gold - base metal quartz veins that vary in width from <1 metre to 4 metres occur at several areas on the property including Surupampa, La Puerta, Edelmira, Mina Leje, and Guadalupe. These veins commonly have small old artisanal workings developed along them, and can contain significant base metals and silver-antimony sulfosalts and/or stibnite while gold grades are variable from low to high. A vein at Surupampa returned the highest gold values yet at the property, 0.3 metres @ 132g/t gold + 45 g/t silver from a narrow oxidised quartz vein. A quartz vein at La Puerta returned a channel result of 2 metres @ 658 g/t silver + 1.33g/t gold + 0.2% antimony with coarse-grained stibnite. Sulfide mineralization in the veins typically comprises around 10% by volume as pyrite, stibnite, sphalerite, galena, and silver-antimony sulfosalt minerals including polybasite. The vein gangue is mostly crystalline and drusy-textured quartz. The quartz - base metal sulfide veins are interpreted to have formed under high temperature intermediate sulfidation epithermal conditions or mesothermal conditions (250 to 300 °C). The presence of copper sulfosalts (including bournonite) and tin sulfide (stannite) in some of the quartz veins suggests a nearby mineralizing intrusion.
An exploration program is recommended including at least 5,000 metres of diamond drilling at the La Puerta area, focusing on the oxide gold potential and the epithermal stockwork mineralization.
A recommended exploration program will involve the checking activities to control geological and assaying information of targets (Fig. 6) released by Darwin and a program of at least 5,000 m of diamond drilling. It is being estimated a total cost of about US$ 4 million.
Hamilton Resources Ltd announced today that they have located and acquired the drill data from their Suriloma project in Northern Peru. 13 different drill holes were completed between 2013 and ...Read more information »
Hamilton Resources Ltd announced today they have completed their study of the newly acquired drill data on their Surilomo Project in Northern Peru. A PDF containing a summary of these ...Read more information »