Posts Tagged CSAMT

CSAMT for gold in Paraguay

Posted by on Saturday, 8 December, 2012

Latin American Minerals Inc.  announces the commencement of CSAMT geophysical surveys at the Paso Yobai Project in Paraguay, an early start to the 2013 exploration campaign to drill the project’s multiple geochemical gold targets. The ground-based geophysical survey will initially focus on the X-Mile Trend prior to covering the Discovery Trend and multiple outlying target areas. The intensive geophysics program is expected to require 2 to 3 months. To follow up the initial deep reconnaissance survey results, the Company will implement the second phase of the program with targeted diamond drilling, expected to start by mid-February 2013.

CSAMT (Controlled Source Audio Frequency Magneto-Tellurics) is a rapid, high-resolution variant of the magneto-telluric class of geophysical surveys, designed to provide detailed section views of lithology and structural features, and to delineate any contrasting zones of hydrothermal alteration. The geophysics survey contract was awarded to Canadian company Quantec Geoscience Limited after a competitive bid process. Quantec is the world leader in deep magneto-telluric and electrical survey technologies for mineral exploration.

Miles Rideout, President and CEO of the Company, stated, “We have seen CSAMT surveys employed with excellent results on many gold systems over more than two decades. Applying this imaging technology at Paso Yobai, prior to drill testing many of our surface gold targets, will allow us to employ better structural information in the initial drill targeting, and will extend our targeting ability to more than 300 metres depth. The high resolution of CSAMT will allow us to better understand the nature, depth and orientation of major mineral targets. The potential benefits to the Paso Yobai gold project include: increased exploration depth, improved drill target identification, reduced reconnaissance drilling cost and improved target prioritization.”

About the Paso Yobai Gold Project:

The Paso Yobai Project is a 15,020 hectare exploration and mining property with multiple large gold showings mapped at surface. The two primary gold bearing structures at Paso Yobai include the 4500 metre Discovery Trend and the 14,800 metre X-Mile Trend. Additional oblique trends and outlying gold zones have been delineated by the Company’s work programs, producing a gold system footprint approaching 100 sq. km. in area.


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.