Posts Tagged silver

The Magnetic/VLF survey in Newfoundland

Posted by on Thursday, 18 October, 2012
Silver Spruce Completes Airborne Survey and Receives Check Assays for the Big Easy Gold/Silver Property, Eastern Newfoundland


Silver Spruce Resources Inc. announces that the high resolution magnetic / VLF-EM airborne survey has been completed and preliminary results received on the road-accessible, Big Easy gold/silver property in eastern Newfoundland. The Big Easy prospect is a large, altered (silicified) system that covers an area of approximately 1.7 kilometres by up to 300 metres wide.   The prospect was drilled in 2011 and 2012 — a total of 12 holes over a 1.2 km strike length, giving significant gold (Au) and silver (Ag) values in a number of the drill holes (news releases September 18, 2012, August 16, 2012 and June 7, 2011).

Airborne Survey
The airborne, high resolution magnetic / VLF-EM survey was carried out in late September by Terraquest Ltd. of Mississauga, ON.    The aim of the survey was to improve the understanding of the geological setting of the area by a lithological/structural interpretation based on the survey results, drilling and surface geology.

The preliminary magnetic data shows a broad, NNE (025 degrees) magnetic high trending through the main portion of the claim group with narrow linear, NNE trending magnetic lows within the overall magnetic high.   The magnetic  lows are offset by linear zones and possible dikes / faults, trending NNW (340 degrees). A sinuous magnetic  low joins the BE and ET zones, continuing to the south of the ET zone.    The preliminary VLF-EM data shows NNE and NNW trending, as well as a number of E-W to ENE-WSW trending conductive zones cutting through the property.

“We are pleased with the resolution of both the magnetic and VLF-EM data.    Based on what we are able to tie into our existing geological and structural compilation, the final results should enable us to better target continued exploration, including drilling,” states Peter Dimmell, President and CEO of Silver Spruce Resources.

Line spacing was 200 m in the known mineralized areas (Big Easy and ET) and 300 m over the rest of the property, at a mean terrain clearance of approximately 70 m. The survey was flown using E-W lines and N-S tie lines for a total of 349 line km. The VLF-EM used two orthogonal receivers, with the main transmitter Cutler, ME.

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Reinterpreted historical EM data for nowadays drilling

Posted by on Sunday, 29 January, 2012

Western Troy Capital Resources has announced the assay results of holes it drilled at its MacLeod Lake Copper/Molybdenum Project in November of 2011.
Three holes were drilled on geophysical anomalies near the Main Zone. Two holes did not intersect significant mineralization, but Hole 228, drilled on an anomaly between the Main Zone and the South Zone intersected 2.14% copper and 21.32 g/t silver over an interval of 3 meters from 63 to 66 meters depth. This interval includes 1.0 meter of 5.93% copper and 50.6 g/t silver.
These widths are believed to be close to true widths due to the sub-horizontal attitude of the mineralized zone.

The map shows the location of Hole 228 relative to the Main and South Zones along with
geophysical anomalies in the area.

Hole 228 was drilled on Rocky Point to intersect a conductive zone south of the Main Zone. Past work in this area uncovered high grade, copper mineralized boulders with assays of 6 to 9 percent copper as well as mineralized outcrop in granodiorite and biotite gneisses.  The mineralized outcrop is likely the up-plunge extension of the new Rocky Point Zone.

(Pink)located approximately 450 meters down plunge from the mineralized outcrop and at the centre of  the conductive zone that appears to represent the outline of the new Rocky Point Zone.

With this new drill intercept in Hole 228, the associated mineralized boulders and outcrop, and the configuration of geophysical anomaly, it is possible that a new zone similar in size and configuration to the South Zone could be present in the Rocky Point area.  The combination of the South Zone and Rocky Point Zone could provide sufficient resources that would allow inclusion of the zones in the mineable resource at some point in the future.


Geophysical characteristics of Porphyry Copper Discovery at Tulameen

Posted by on Thursday, 20 October, 2011

Leonard W. Saleken, Chairman of Goldcliff Resource Corporation reports that Goldcliff has made the first significant porphyry copper ore grade discovery in the Copper Mountain mining district in decades. With surface samples highlighted by 0.655% copper – almost double the current reserve grades at the Copper Mountain Mine – and 1.3 grams per tonne silver, the Trojan showing is part of the Bolas anomaly, which is located in the Whipsaw target on the Tulameen property in the Copper Mountain mining district near Princeton, BC, Canada. The Tulameen property is 100 per cent owned by Goldcliff.

The three-pronged Bolas anomaly also contains the Eagle showing, which is highlighted by 0.175% copper and 1.0 grams per tonne silver. The copper mineralization on both the Trojan and the Eagle showings is chalcopyrite with malachite, and the iron sulphides are pyrite and pyrrhotite along with magnetite. These showings are situated on surface, above the substantial Bolas deposit-style chargeability anomaly. The Bolas anomaly is 2,000 long by 1,200 metres wide, and merges to form an area of 1.5 square kilometres at about 300 metres.

The Whipsaw alkalic porphyry copper-silver target area is located along the Copper Mountain south-west copper trend, approximately seven kilometres south-west of the Copper Mountain ore bodies. The Copper Mountain mineral reserves are 232,776,000 tons grading 0.36% Cu, 0.09 Au and 1.25 g/t Ag. The Trojan and Eagle showings are associated with the Bolas anomaly, which contains disseminated sulphide mineralization in the 3 to 5% range.

Bolas 3-D IP Anomaly

The deposit-style Bolas chargeability anomaly is a disseminated iron sulphide body that is located near surface and extends to an estimated depth of 500 metres in Upper Triassic Nicola Group rocks. The Bolas anomaly measures approximately 2,000 meters in a northwest direction by about 1,200 meters southwest. At a depth of around 300 meters, the anomaly merges to form a chargeable body of the order of 1,800,000 square meters or 1.8 square kilometres in size. The iron sulphide content of the rocks within the Bolas anomaly is estimated to be 3 to 5%.

Chargeability

The Bolas chargeability anomaly is a three-pronged star feature with a vertex centre and three end nodes that are referred to as the Whip, Elk and Eagle node areas of chargeability. Close to the surface, the chargeability response millisecond (ms) levels are weak to moderate. With increasing depth, the chargeability response millisecond levels become stronger and begin to merge at about 150 meters in depth. As depth continues to increase, the chargeability star features ultimately merge to form the continuous chargeability anomalous area. The chargeability values in the Bolas anomaly reach their maximum (25 to 30 ms) at about 300 meters below surface and then begin to fade to around 20 to 25 ms at 500 meters.

Whipsaw Target Area

Magnetic Environment

The most visible magnetic feature of the Whipsaw Target is a strong, broad, crescent-shaped magnetic high that fills more than half of the area. Inversion of the ground magnetic indicates that the deep-seated, crescent-shaped magnetic high is consistent with a deep-seated magnetic intrusive rock. A similarly intense, broad crescent-shaped magnetic high in the Copper Mountain area corresponds with mapped diorite intrusive rock and suggests that the magnetic high in the Whipsaw area may well be caused by the same rock type at depth.

The Whipsaw crescent-shaped, magnetic high partially surrounds a subcircular magnetic feature that is low, compared to the crescent-shaped high, but higher relative to magnetic background seen to the north. Once again, a similar pattern can be observed in the Copper Mountain area. There the subcircular magnetic feature corresponds with rocks mapped as monzonite and syenite, suggesting that the deep subcircular magnetic feature at Whipsaw may also be caused by a similar, less magnetic rock type. Strong chargeability anomalies occur within the subcircular magnetic feature.

Resistivity Data

Analysis of inverted resistivity data, with help from chargeability and magnetic inversions as well as magnetic intensity, indicates that the Princeton/Nicola contact may be vertical to sub-vertical and that the Princeton Group rocks could vary from about 150 to over 500 meters in depth, possibly over Nicola Group rocks. This may mean that the area of Princeton rocks could be down-dropped relative to the Nicola rocks across a fault-forming graben. If this is case, the deep moderate to weak chargeability anomalies seen in the area of Princeton rocks may then reflect the tops of chargeable material buried within Nicola rocks.


Detailed Geophysical Survey in Argentina

Posted by on Tuesday, 27 September, 2011

Metallum Resources Inc. announces that is has completed a detailed geophysical program covering, and extending beyond, the known gold/silver mineralization exposed for approximately 1.2 kilometres (“km.”) of strike and 0.5 km. of width on surface at its M-18 gold/silver property in Chubut province, Argentina. The objective of the geophysical program was to assist in defining additional strike length, width, and depth to this mineralized zone. Gold and silver occurs disseminated within a low sulphidation system of quartz veining and quartz stockwork.

Quantec Geoscience (Mendoza, Argentina) completed approximately 58.8 line km. of gradient Induced Polarization (“IP”) and ground magnetics with supporting coverage using pole-dipole IP. The original planned geophysical program called for approximately 42 line km. of survey (see Metallum’s press release of August 11, 2011), however, open-ended anomalies identified after completion of the original planned program required additional work to properly investigate these anomalies along strike.

Geophysical coverage extended approximately 1.4 km. and 500 m respectively along strike in each direction beyond the exposed gold/silver mineralization as well as approximately 800 m in each direction beyond the exposed width of the mineralized zone. The survey coverage included evaluation of a large untested zone of argillic alteration occurring within a few hundred metres of the known gold/silver mineralization.

Results from the geophysical survey showed that the known exposed zone of gold/silver mineralization is clearly identified on the gradient and pole-dipole IP chargeability and resistivity at depth and along strike. Furthermore, IP anomalies related to this mineralized zone extend beyond the exposed rock beneath the cover of gravels, indicating that the gold/silver mineralization is potentially continuing along strike. In addition to this, the large zone of argillic alteration shows a strong chargeability/low resistivity anomaly extending for approximately 2 km in strike and 600 m in width. Depth extent to this zone continues beyond the 250 m investigation depth of the IP detectability.

View IP gradient chargeability map:

As well, the ground magnetics survey supports some of the structural features identified by the gradient IP and has also identified a strong magnetic feature on the east end of the survey area which will be investigated by geological work and/or drilling.

Metallum also reports that the geological program comprising an extensive campaign of geological mapping, detailed channel sampling, and approximately 8 km. of trenching with channel sampling is planned to commence during October, 2011. The objective of the program is to expose additional strike and width to the 1.2 km strike and 0.5 km width of the known gold/silver mineralization, which is covered by a thin veneer of gravels at its perimeter and remains open in all directions. As well, the geological work will evaluate the large zone of argillic alteration (mentioned above) in context with the strong IP chargeability/low resistivity response identified from the geophysical survey.

Results compiled from both the geophysical program and planned geological/sampling programs will identify primary targets for a Phase 1 drilling campaign planned for Q-4, 2011.

Metallum’s President and CEO, Greg Lipton, states that “Metallum is excited by the results from the geophysical program. The known zone of gold/silver mineralization clearly shows strike extension beneath the gravels as well as at depth. In addition, the strong IP chargeability/low resistivity anomaly covering the large, untested zone of argillic alteration is indicative of mineralization continuing at depth. Also, additional, highly anomalous geophysical targets have been identified elsewhere on the property. Metallum now looks forward to the detailed channel sampling and trenching program that is about to begin on the property to add another dimension for target development for the Company’s drilling program.”


VLF-EM and magnetic anomalies under testing

Posted by on Monday, 8 November, 2010

Newmac Resources Inc. has received results from its trenching program and a second VLF-EM and magnetic survey recently completed on the Company’s Raft Property (previously referred to as the Ready Mix property) located approximately 35 km northeast of Clearwater, British Columbia.

Trench E has located the high grade bedrock source of gold on the Raft property for the first time in history. Representative grab samples of mineralization in two meter intervals from the central part of Trench E assayed 46.9 g/t Au, 59.9 g/t Ag and 1.56 g/t Au, 3.9 g/t Ag respectively. The actual total width of mineralization remains unknown as deeper than expected overburden only allowed for a portion of the VLF-EM target to be tested. Soil samples taken continuously beside the mineralized bedrock to the northeast of the high grade samples for 30 meters assayed between 3 and 50 ppb gold indicating that the zone could be wider than the 4 meters sampled. The mineralization is epithermal in character from an intrusive gold deposit as shown by the gold to silver ratio with associated base metals, arsenic, trace bismuth and antimony. The mineralized samples are on a 500 meter long VLF-EM conductor which has only been tested by Trench E. Numerous other VLF-EM conductors in a similar orientation remain untested on the property.

A total of 5 trenches (numbered A – E) were completed to test 5 different VLF-EM and magnetic structures located near anomalous gold soil samples. The first three trenches (A-C) did not locate mineralization. Trench D encountered anomalous levels of gold (165 ppb in one representative grab of soil). All 5 trenches were sampled by taking representative grab samples every 2 meters of either rock or soil. Grab samples are selective by nature and are unlikely to represent average grades on the property.

The Company has also completed a second VLF-EM and magnetic survey on an area not covered by the initial survey. A number of the new structures have been outlined in this survey, and the company plans to follow up on them in the future.

The Raft property has now been expanded to 13,881.21 hectares or 138.81 square kilometers.

David Schmidt, President and CFO of Newmac Resources Ltd. Stated “Making a brand new discovery in British Columbia is an exciting way to finish off our Phase One program at Raft. 2011 will be an exciting year as we will further test this VLF-EM structure and several other similar ones located on the property.”

The Company is currently planning a second phase program to follow up on this very successful first phase program.

Historically a stream sediment of 87 ppb gold was obtained from Martin Creek by the property vendor during his initial prospecting of the property. He also in 1999, uncovered a highly oxidized bolder of intrusive breccias which assayed 29.3 g/tonne gold and 202 g/tonne silver.

The Company views the Raft project as an excellent target for intrusion related gold mineralization because of several tungsten skarns in the area, anomalous gold, tungsten, molybdenum, arsenic in stream sediments, and Shuswap metamorphic terrain intruded by Cretaceous granites which have been recognized as causing the mineralization.

The Company has the right to earn a 100% interest in the Ready Mix claims (part of the Raft Property) by making an initial payment of $5,000 and issuing 150,000 common shares. Within two years the company will need to pay an additional $25,000 and issue 500,000 common shares, in two stages. The property will also be subject to a 2% Net Smelter royalty, where the full 2% may be purchased by the Company for $1 million at anytime.


Geophysics Survey in Southern Peru Defines Several Exploration Targets

Posted by on Monday, 1 November, 2010

Duran Ventures Inc. provides a summary of exploration activities at Ichuña Project located in southern Peru. The Company has completed the latest field campaign at Ichuña, which includes detailed geological mapping at a scale of 1:2000, detailed channel sampling, and an extensive geophysical survey with VDG del Peru S.A.C. The geophysical survey commenced on August 19th and was completed on September 29th. A total of 26.3 line kilometres of induced polarization (IP) and 97.8 line kilometres of magnetic (MAG), spectrometry (SPEC) and differential GPS (DGPS) were completed.

Geophysical Survey Results

The geophysical survey carried out by VDG del Peru S.A.C. was successful in outlining several anomalies in the study area. Approximate outlines of the induced polarization (IP) chargeability high anomalies are shown on the accompanying map as hatched areas with dashed outline and numbered IP1 to IP4: resistivity high anomalies are shown as shaded areas and numbered RES1 and RES2. IP chargeability anomalies are generally interpreted as zones of disseminated sulfide minerals, while resistivity anomalies are often interpreted to represent areas of different rock types and alteration in host rocks.

IP anomalies IP1 to IP3 coincide roughly with resistivity anomaly RES1. The RES1 anomaly, which roughly underlies the intrusive rocks, appear to host the majority of the Cu-Ag mineralized zones of Sayhuani, Sayhuani West, Sayhuani East, Jatun West, Jatun East, and Jatun South. This resistivity anomaly is approximately 0.5 to 1.0 x 2.0 kilometres in size, oriented with a north-northwest trend. Sayhuani West Zone, which contains the highest silver results to date, appears to occur where IP1 overlaps RES1, and remains open to the north and northwest.

The largest IP chargeability and resistivity anomalies, IP4 and RES2, occur in the southwestern side of the property, in an area with almost no outcrop. The east-west to west-northwest orientation is similar to the orientation of the nearby Canahuire deposit which was noted to be a blind discovery. At Ichuña, the anomaly is approximately 0.6 to 1.0 x 1.8 kilometres in size. The strong IP response (IP4) in this area is coincident with high resistivity values (RES2) may indicate strong silicification and sulfide mineralization localized along this important west-northwest trend.

The K/Th spectrometry map outlines an extensive area on the northern side of the survey grid which coincides with surface outcrop of intrusive and volcanic rock. The area of strongest K/Th anomaly coincides with strong copper and silver mineralization in the Sayhuani, Sayhuani East, and Sayhuani West Zones.

Geological Model

Geological mapping carried out during this program shows sedimentary clastic and carbonate rock cut by high level intrusive and volcanic units. Strongly anomalous copper and silver mineralization occurs near sediment-intrusive contacts, as disseminations in intrusive units, and in stockwork zones in both sedimentary and intrusive or volcanic units. Company geologists are interpreting the Ichuña system as being the upper levels of a porphyry copper system, with associated vein structures developed in both host sedimentary and intrusive units. The system has seen considerable surface oxidation, with common iron oxide minerals such as limonite, goethite, and jarosite. Visible copper occurs as secondary or remobilized minerals, including malachite, azurite, chrysocolla, tenorite, and chalcocite. These are indications that there is a capping of leached rock with the potential for supergene enrichment of copper at some depth. Elevated silver values with relatively little evidence of silver-bearing sulfide minerals may indicate that there is supergene enrichment of silver as well. The extensive surface area with strongly altered rock and elevated copper, silver, lead, zinc, arsenic, barium, and antimony indicates the potential for a strong intrusive-driven hydrothermal system underlying the Ichuña Project. Mineralized structures form two distinct populations, one of which ranges in strike direction or trend between 30 to 80 degrees, and the second between 110 to 160 degrees.

Jeff Reeder, CEO of Duran Ventures, reports that, “We are very encouraged with the results from this work campaign at Ichuña. The combination of widespread, significant copper and silver values with strong geophysical anomalies indicates strong exploration potential at Ichuña. Continued development work at nearby Canahuire, one of Latin America’s most recently discovered and significant gold-silver deposits, helps to highlight the quality of exploration targets in this area.”

All geological, geochemical, and geophysical data is being compiled in order to prepare the project for diamond drill testing.