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Vaquillas Mine QB & Drill Holes
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Vaquillas Prospect Schematic Cross Section
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NueveVidas-Cenizas Annotated
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NV QB Image & Drilling - March 2011
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NV Geology & Drilling - March 2011
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NV Geology & Trenches - March 2011
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Precious Metals Targets
Vaquillas Mine
The abandoned small open pit mine and related underground workings at the Vaquillas Mine area are located along the Vaquillas Fault, about half way between the Vetas Negras and Victoria vein systems, on a modest structural high that is surrounded by post-mineral Miocene gravels and ignimbrites. Small, near-surface workings were exploited around the turn of the 19th century. The prospective area was subsequently explored and exploited on a small scale by Empresas Mineras BHC during the 1980s, and then explored by Rayrock in joint venture with BHP in the 1990s - both efforts carried out in a different economic and metals price environment to that of today.
The main host to the hydrothermal alteration and mineralization at Vaquillas is a series of andesitic volcaniclastic sediments, epiclastic breccias and lithic tuffs of Late Jurassic to Early Cretaceous age, together with rhyolite/dacite domes that occur predominantly to the SW. Cross-cutting, fine-grained, sub-volcanic andesitic/basaltic stocks and dykes also occur. Hydrothermal alteration that affects most of the volcaniclastic rocks is dominated by illite and smectite, although a distinct dark chlorite flooding phase is also recognised. It is possible that sericitic alteration takes over at deeper levels.
Mineralization at Vaquillas consists of N-S to NNW trending, steeply W dipping, mineralized tectonic breccia bodies together with multiple fine veinlets of quartz and/or sulphide between the main breccia bodies. Disseminated, breccia matrix-filling, and veinlet controlled pyrite, together with a series of black silver minerals, likely sulphosalts, argentite and acanthite, occur. Sphalerite is sporadically abundant in the mineralized tectonic breccias, together with minor galena and trace copper minerals including enargite. Calcite, quartz and barite also occur in the mineralized breccias, with calcite and/or semi-massive sulphide breccia matrix-fillings being a good guide to significant precious metals values.
An important suite of later NW to WNW trending quartz veins, with altered and bleached halos, cross-cut the main Vaquillas breccia structures, and in some cases may displace them slightly. These cross-cutting veins typically have higher gold and silver values than the Vaquillas breccias. The predominant veins are typically 0.5m to 2m wide, have strike lengths of the order of several hundred metres before disappearing under post-mineral cover, have been the subject of historical shallow workings (probably within the oxide zone only), and occur in at least 4 main sets: to the SW, N, E and W of the Vaquillas pit. One example, to the SW of the Vaquillas open pit, includes a vein exposed in historic trench Z6 at surface that grades 5.33 g/t Au and 290 g/t Ag over 1.5m, and which was intersected in historic drill hole VRC-11 drilled by Rayrock at about 75m vertical depth with grades of 6.18 g/t Au and 118 g/t Ag over 7m (not true width). Other high grade intercepts, notably in drill holes VVQRC-09-003 (1m @ 37.5 g/t Au and 68.4 g/t Ag), VVQRC-09-005 (1m @ 4.94 g/t Au and 60.9 g/t Ag), VVQDD-10-033 (1.13 m @ 78.3 g/t Au and 802 g/t Ag), VVQDD-10-035 (1.21m @ 18.8 g/t Au + 392.0 g/t Ag), VVQDD-10-041 (1.85m @ 5.79g/t Au + 20.0g/t Ag), may also represent cross-cutting veins and/or their intersections with the approximately N-S trending breccia bodies. Significant further work remains to be done to evaluate the potential of these high-grade veins.
The entire Vaquillas Mine area is underlain by a significant IP gradient array chargeability anomaly that is approximately 1-2km wide and is bound to the west and east by the Cenizas and Vaquillas master faults respectively, and also extends along strike (NNW-SSE) for more than 5km as far as the Chaco Quebrada to the south. The anomaly probably reflects a very large sulphide system at depth.
The whole area has been affected by supergene oxidation and leaching to variable depths, but typically in the order of 40m. Abundant iron oxides, sulphates and supergene kaolinite are products of the supergene processes in the oxide zone.
The bulk of Hochschild's drilling to date has been oriented ENE-WSW to intersect the main Vaquillas breccia structures in order to test a potential open-pittable, oxide, and mixed oxide/sulphide precious metals resource related to the breccia bodies.
Most drilling to date by Hochschild has been RC (approximately 8,883m of RC drilling in 32 holes), with a further 20 diamond drill holes (approximately 4,619m of diamond drilling). The best results received to date are summarized in the following link:
http://www.ironcreekcapital.com/i/pdf/Victoria-Vaquillas_Drill_Intercept_Summary.pdf
Two diamond drill hole twins to previous reverse circulation holes returned significantly better gold and silver values (see following table), suggesting losses of fine material in the presence of water in the earlier RC drilling. Diamond drill hole VVQDD-10-32 was drilled as a twin to reverse circulation hole VVQRC-09-017, and diamond drill hole VVQDD-10-35 was drilled as a twin to reverse circulation hole VVQRC-09-018.
| DRILL HOLE |
From (m) |
To (m) |
Total Intercept (m) |
Au (g/t) |
Ag (g/t) |
| VVQDD-10-032 |
67.13 |
169.00 |
101.87 |
0.91 |
56.87 |
| VVQRC-09-017 |
63.00 |
165.00 |
102.00 |
0.44 |
37.35 |
| VVQDD-10-035 |
237.05 |
281.55 |
44.50 |
0.64 |
7.29 |
| VVQRC-09-018 |
237.00 |
282.00 |
45.00 |
0.47 |
6.11 |
Hochschild's drilling has shown that the principal breccia bodies occur over a strike distance of approximately 1km. The 73m long intercept reported in drill hole VVQDD-10-047 occurs towards the centre of the mineralised zone, and supports the presence of a significant zone of mineralisation previously indicated by drill hole VVQDD-10-035.
Drill hole VVQDD-10-046 indicates continuity to the north of the principal breccia body, supported by narrow intercepts on subsidiary structures in drill holes VVQDD-10-034, 036, 037 and VVQDD-10-048.
Drill hole VVQDD-10-040 returned no significant results suggesting that the main mineralised bodies are either cut off or displaced to the north, with only narrow, low-grade intercepts reported. To the south, the main mineralised bodies are partially obliterated by a post-mineral mafic intrusion, although a large number of narrow, moderate- to high- grade structures were intersected in drill holes VVQDD-10-041, 043, 044, 045, 046, 047, 048, 049 and 050, suggesting possible horse-tailing of the main structures seen in the centre of the area.
Nueve Vidas
Nueve Vidas comprises a medium-grained, porphyritic diorite hosting veinlet and disseminated magnetite with chlorite and epidote, exposed in trenches and minor outcrops, located immediately SW of the large Cenizas colour anomaly. Drilling in and around Nueve Vidas has also identified tonalite, monzonite and granodiorite intrusive phases that have been collectively referred to as the Nueve Vidas Intrusive Complex (NVIC). The magnetite-rich diorite porphyry coincides with a strong, approximately circular magnetic high feature more than 1Km in diameter. Trenching and drilling indicates that the NVIC is cut by a series of narrow, NW trending, iron-oxide and jarosite-stained, clay filled fault/gouge zones at surface that appear to correlate with sulphide-rich structures in drill holes at depth.
Previous exploration work at Nueve Vidas includes trenching, shallow RAB drilling, and 2 shallow, inclined RC holes by RTZ in the early 1990s; colluvial and enzyme leach surveys by Fremont Gold in the late 1990s; and shallow, inclined RC drilling over a very small area by El Dorado Resources in 1999 (1,162m in 9 RC holes).
Mineralization appears to occur in two principal styles:
•Higher-grade, cross-cutting, structurally controlled gold (+ Ag +/- Zn +/- Cu) within sulphide-rich breccia/fault zones, typified by historic intercepts such as 4m @ 6.69 g/t Au + 22.6 g/t Ag (+ 0.11% Cu) in RTZ trench TR27, and drill intercepts such as 12m @ 8.91 g/t Au + 21.6 g/t Ag (including 4m @ 22.18 g/t Au + 36.1 g/t Ag) in Hochschild drill hole VCNRC10-004. Hochschild drill hole VCNRC-10-016 intersected 1m @ 6.38g/t Au + 53.2g/t Ag; and VCNRC-10-021 intersected 4m @ 8.94g/t Au + 38.8g/t Ag (with highly anomalous Cu and Zn) in this style of alteration.
•Lower-grade, disseminated gold (+/- Cu +/- Ag) within the altered dioritic porphyry, typified by historic intercepts such as 90m @ 0.59g/t Au in RTZ trench TR20; 24m @ 0.83g/t Au in El Dorado RC hole RC99-01; 19m @ 1.03g/t Au in El Dorado RC hole RC99-03; and 8m @ 1.09g/t Au in El Dorado RC hole RC99-10. Hochschild drill hole VCNRC-10-017 intercepted 22m @ 0.85g/t Au; and VCNRC-10-021 intercepted 74m @ 0.40g/t Au (including 16m @ 0.72g/t Au and 10m @ 0.51g/t Au) in this style of alteration.
Principal drill intercepts are summarised in the following link:
http://www.ironcreekcapital.com/i/pdf/Victoria-NueveVidas_Drill_Intercept_Summary.pdf
Two principal models are currently proposed for the gold mineralisation at Nueve Vidas:
•Diorite-hosted porphyry gold style mineralisation
•IOCG-related gold mineralisation
In either case, later cross-cutting structures are the focus of higher-grade gold mineralisation with associated silver.
Hochschild has completed a total of 3,435m of RC drilling in 10 holes in the Nueve Vidas area to date.
Victoria (I, II & III)
The Victoria silver veins are separated into three sub-areas -- Victoria I, II and III -- and are located to the south of the Chaco Quebrada and to the east of Cenizas and Nueve Vidas, along the southern continuation of the Vaquillas Fault structure. All work by Hochschild has been concentrated on the Victoria II cluster of veins to date. Veins exposed at surface and in old workings at Victoria are composed of manganese and iron oxides, manganese and iron carbonates, quartz, barite and minor calcite, often displaying banded epithermal textures. The host rocks at Victoria II are porphyritic dacites, and clastic and volcanic sediments and tuffs of Upper Jurassic age, underlain by carbonate sequences at depth. Unaltered micro-diorite dykes cross-cut the area. Hydrothermal breccia-vein structures are also apparent. At surface the structures are highly anomalous in silver, antimony, mercury, lead and zinc, with minor gold and arsenic. Typical silver grades from surface sampling of exposed veins range from 10 g/t to +300 g/t.
Hochschild has completed 2,015m of RC drilling in 9 holes at Victoria II targeting the principal mapped veins at depth. No significant results were recorded.
Vetas Negras
Hochschild abandoned the Vetas Negras in-holding during 2010.
Qualified Person
Demetrius Pohl, Certified Professional Geoscientist (CPG), is the Company's Qualified Person as defined by National Instrument 43-101, and is responsible for the accuracy of the technical information in this project summary. Dr. Pohl has verified that it is an accurate summary of the reports provided to Iron Creek by Hochschild, and contained within reports by historic workers. However, Iron Creek has not independently verified Hochschild's exploration results, or those of historic workers.
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