Posts Tagged Zonge Geoscience

Gravity and IP surveys in Nevada

Posted by on Wednesday, 23 May, 2012
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Liberty Silver Corp.  announces the successful completion of its 2012 geophysical program at the Trinity Project, located in Pershing County, Nevada. The Gravity and Induced Polarization (IP) surveys were successful in locating significant new drilling targets concealed by alluvial cover and in delineating the structural fabric of the district. The geophysics program was designed and interpreted by Jim Wright of J.L. Wright Geophysics. All the new data and the substantial amount of historic data relating to past operations at the Trinity Project have been input into a GIS database which will be used to further define future drilling and development of the current resource and multiple exploration targets.

Under the direction of Mr. Wright, Magee Geophysical Services of Reno, Nevada conducted the gravity survey consisting of 532 stations covering approximately 26 square kilometers. The survey delineated the shallow eastern edge of the Sage Valley basin. High-angle structures of two primary orientations offset the Tertiary volcanic-pre-Tertiary sediment package into a complex series of steps resulting in structurally defined basins. Most notable is a graben filled with volcanic rocks which hosts the Trinity silver deposit that is underlain by a chargeability anomaly. A second major chargeability anomaly south of the Trinity pit is located in the same graben.

A possible northern extension of the Trinity silver deposit is hypothesized based upon the gravity survey. Historic IP data, acquired in 1983 (the “Historic IP”), indicates a possible northern continuation over this area as well. Historic airborne magnetic results coupled with the gravity and new IP also suggest a continuation of the known mineralization to the southwest along the Trinity fault. The gravity and Historic IP data, coupled with several other data sets, indicate that several target areas exist, including two possible target areas along the strike extensions to the known silver mineralization, and several other untested chargeability anomalies similar to that of the Trinity silver deposit.

Based upon the gravity and historic geophysical results, eleven (11) IP lines (35 line kilometers) were completed by Zonge Geoscience to enhance the level of detail of the chargeability anomalies detected in the Historic IP survey. All eleven lines detected chargeability responses consistent with that survey. Most notable is a strong chargeability zone located approximately 500 meters (“m”) south of the known Trinity silver deposit and is defined by four IP lines from the new IP survey. The strike length of this anomaly is greater than 600m and is still open to the north and south and ranges from 500m to 700m in width in an east west direction. Furthermore, the graben interpreted from the gravity survey is further supported by the new IP results, thus increasing the thickness of the favorable host rock package. U.S. Borax (“USB”), the former operator at Trinity, drilled three holes into this zone in the mid-1980s and all three holes intersected considerable silver mineralization but due to low silver prices, further delineation of the silver mineralization was not carried out. The USB drill holes also stopped short of testing the chargeability anomaly found by the new survey. The three holes (S-21, S-70, and S-132) encountered silver mineralization ranging from 2.0 grams/tonne in an interval of 1.5m to 43 grams/tonne in an interval of 1.5m but were not drilled to conform to National Instrument (NI) 43-101 standards and, while significant, are considered as non-compliant historic data only.

Bill Tafuri, President and COO, said, “The results of these surveys are very encouraging and they demonstrate the potential for extending the known resource under the covered areas. They also have defined specific targets to drill under the covered areas making our exploration program much more focused and cost effective”.

Liberty Silver is currently completing its initial drilling program on the Trinity Property. Assayed results from the program are expected to be released in the near term.


GEOPHYSICAL RESULTS: NEW EXPLORATION TARGETS AT KIZILTEPE

Posted by on Friday, 3 June, 2011

Ariana announced geophysical  test results from their Kisiltepe project in Turkey.

The programme has successfully confirmed the presence of several potential vein systems in the northern half of the prospect area.

Highlights

  • Several resistivity and chargeability anomalies, which may coincide with buried vein systems, located to the northeast of the Arzu South vein.
  • One significant new anomaly coincides directly with an area of extensive quartz vein float from which grades of up to 21.1 g/t Au have been recorded.
  • Significant additional exploration upside defined on the prospect.
  • Exploratory drilling programme to commence within days.

Dr. Kerim Sener, Managing Director, commented:

“These geophysical results coupled with systematic sampling have demonstrated the potential for further significant veins to be discovered at the Kiziltepe prospect.  These geophysical anomalies will be targeted by exploration drilling.  The first phase of this drilling is due to commence over the weekend (27/28 March) and its aim will be to confirm the presence of these buried vein systems or their associated alteration.  There is clear potential at the prospect to increase the current mineral resource and to further enhance the economics of the project.”

Geophysical Programme

The geophysical programme described here was undertaken over a 2km2 area covering the northern half of the Kiziltepe vein field in an area where no veins appear in surface outcrop.  Detailed mapping of the area had previously identified the potential for buried vein systems and sampling of one area of extensive quartz sub-crop outlined grades of up to 21.1 g/t Au in composite rock-chip sampling of float material.

Data was collected from nine northeast-southwest oriented Induced Polarisation (IP) / resistivity profiles, which were spaced 180-230m apart and designed to coincide directly with existing geochemical data lines (total length surveyed is approx. 12km).  A pole-dipole array was used with 30m or 60m electrode spacing, using a Zonge GGT-3 transmitter and a Scintrex IPR-12 receiver operating in the time domain.

Several high chargeability and high resistivity anomalies were identified in the two-dimensional inversion models, which are interpreted to coincide with zones containing vein systems and their related alteration.  Zones with resistivities greater than 150 Ohm.m, in places coinciding with chargeabilities less than 10mV/V, were identified as significant anomalies.

In plan, the distribution of the anomalies is broadly coincident along three distinct trends; one in the immediate vicinity of Arzu South (possibly representing a splay), another directly beneath a hill which conceals part of the Arzu structure and one in the vicinity of the Vein 5 structure.  These trends possibly represent new vein systems at depth, which must be tested by drilling.  An initial programme of drilling comprising several short test holes will be focused on certain of these areas.  No more than 1,000m of drilling is envisaged for this initial programme.

Figure 1 showing an inverse model resistivity (top) and chargeability (bottom) profiles on Line 2 viewed looking to the northeast.  Towards the left-hand side of the sections a resistive body is identified which possibly represents a north-south trending splay off the Arzu South structure.  Approximately midway along the section (just to the left of the 480 mark) is a distinct resistive body which corresponds directly with the area of quartz vein float from which several highly anomalous results were obtained in rock-chip sampling.  Towards the right-hand side (near the 960 mark) a resistive body is coincident with a discrete high chargeability anomaly and this does not correspond to any known vein system and represents a new target area for drilling.


All That Glitters: Geophysical Exploration for Precious Metals

Posted by on Sunday, 7 March, 2010

it was a theme of Canadian Exploration Geophysical Society’s a timely and informative full-day symposium which took place yesterday in Toronto and timed to PDAC-2010. A roster of noted industry experts presented papers focussing on exploration and extraction of gold, silver, and platinum group metals. The symposium included an introductory overview of key geological aspects of important types of Au, Ag, and PGM deposits, cover particular geophysical surveys and applications, case studies, and look at promising future technologies.

The companies which made the presentations: Barrik Gold Exploration; SRK Consulting; MB Geosolutions; Condor Consulting; Fugro Airborne; Aeroquest Surveys with Teck REsources; Geotech Ltd.; Zonge Egineering with Terra Res.; Quantec Geoscience; JVX Ltd.; Abitibi Geophysics; SJ Geophysics Ltd.; Southern Geoscience Consultants; Levon Res with Coro Minera and Fritz Geophysics; Geophysical Algorithms; RMIT; Geoscience BC; GSC; University of Quebec; Ontario Geological Survey with PGW.

http://www.kegsonline.org/?dir=event&sub=&id=8002


CSAMT for gold in Idaho

Posted by on Wednesday, 17 February, 2010

The Controlled-Source Audio-Frequency Magnetotellurics (CSAMT) survey was conducted by Zonge Geosciences Inc. for Otis Gold Corp., between October 19th and October 27th 2009 and consisted of data acquisition from six N45E-oriented survey lines for a total of 8.5 line-kilometers of coverage. Detailed geophysical interpretation of the CSAMT survey data was conducted by James L. Wright of J. L. Wright Geophysics, Spring Creek, Nevada, during the latter half of December 2009.

Otis Gold Corp. announces the results of a recent CSAMT geophysical survey that indicates the presence of numerous sizeable and geologically significant resistivity anomalies underlying the Dog Bone Ridge gold target area located at the Kilgore Gold Project, Clark County, Idaho. The target area, which has only been minimally tested by historic drilling, is located approximately 1,200 meters southwest of the known Kilgore gold deposit and comprises most of the core of the larger epithermal system containing the deposit (see http://www.otisgold.com/news/06-10-2008/ and http://www.otisgold.com/blog/gold-intercepts-at-kilgore/). Of the five CSAMT anomalies detected by the survey, only three have been initially tested by historic drilling, with all drill holes in these three anomalies containing significant intercepts of gold mineralization.

Based on the lack of drilling and the fact that the anomalies are sizeable (upwards of 1,200 meters in length), a 2,000-meter, 6-hole drill program is planned to test the highest priority anomalies and offset some of the known historic drill-hole intercepts during the 2010 field season. This drilling is part of a larger 8,000-meter drill program planned for the Kilgore Gold Project in 2010.

The Dog Bone Ridge gold target comprises an extensive area of 242 hectares mostly overlain by an apron of Pliocene-age hot-spring sinter and explosion breccia that caps lithic tuff, the same rock unit that hosts the Company’s nearby Kilgore gold deposit. Of the three CSAMT anomalies associated with historic and significant drill-hole intercepts, the most northerly (Target C1) coincides with Kilgore Gold Company drill holes KG04-02 containing 51.8 m @ 1.25 grams/tonne (“g/t”) gold (“Au”) and KG06-01 with 12.6 m @ 1.57 g/t Au. Within the hole KG04-02 intercept a higher-grade intercept of 3.1 m @ 15.9 g/t Au was reported that coincides directly with the slightly higher resistive core of the anomaly, possibly reflecting a silicified structure. The second, or central, CSAMT anomaly (Target D3) associated with historic drill-hole intercepts coincides with Echo Bay core hole 96EKC-178 that contains 99.4 m @ 0.428 g/t Au and further contains within this intercept higher grade intercepts of 4.6 m @ 2.57 g/t Au, 10.7 m @ 1.51 g/t Au, and 3.1 m @ 2.57 g/t Au. Gold mineralization in these holes is hosted within silicified lithic tuff.


The survey was conducted using a 50-meter electric-field receiver dipole in spreads consisting of four electric-field dipoles with a magnetic-field antenna located in the center of the spread. The data was acquired in the broadside mode of operation with the electric-field dipoles oriented along the survey line and parallel to the transmitter dipole. The magnetic antenna was oriented perpendicular to the survey line. One CSAMT transmitter of a grounded dipole configuration was used for the survey. The survey was conducted to search for low to moderate resistivity bodies containing higher resistivity cores near or associated with structures that may have acted as conduits for gold mineralization.

A detailed location map of the CSAMT survey grid lines and resultant anomalies, along with the historic drill-hole intercepts associated with these targets, can be found on the Otis website at http://www.otisgold.com/projects/kilgore . Although a few additional and widely scattered historic holes were drilled in the Dog Bone Ridge target area, they either were not drilled deep enough to reach the newly discovered CSAMT anomalies or they were angled away from and/or off the flanks of them, missing them completely.