Magna Terra Minerals Inc. announced that generative efforts have resulted in the discovery of encouraging surface gold mineralization on a new low sulphidation epithermal vein style project in the Deseado Massif region of Santa Cruz Province.
The Piedra Negra Project is located approximately 30 km N-NE of the Cerro Vanguardia gold mine (Anglo-Ashanti). The Project is accessible by a good unpaved road, from Tres Cerros, 32 km to the east.
The Project is characterized by gold bearing, low sulphidation veins and stockworks, hosted in andesitic tuffs and rhyolitic domes of the Bajo Pobre and Chon Aike Formations respectively. The 356 select rock chip samples reported so far are distributed across an area measuring 2 km from north to south and between 200 and 700 m from east to west. Gold grade ranges up to 13.35 ppm with an average grade of 0.397 ppm. There are 250 samples equal to or above detection for gold, 150 of which are greater than or equal to 0.1 ppm. The company notes that samples on this project are selected samples, with spacing being determined by availability of outcrop and sub-crop, and are not necessarily representative of the mineralization hosted on the property.
There are four mineralized zones which vary significantly in character in terms of geology and mineralization.
- The Vetas Hermanas zone includes the site of the initial discovery and is characterized by 1,000 meters of low sulphidation, banded, crustiform and cockade texture veins which are hosted in ash tuffs and andesitic tuffs. Results from 121 samples reported from veins and breccias in the area range from detection to Au 8.23 ppm with an average grade of 0.616 ppm. There are 4 veins of interest in this zone, The Emily Vein, Valentina Vein, Brunella Vein and Jasmin Vein. Emily and Valentina strike N-S whereas Jasmin strikes NNE and Brunella is irregular in strike appearing to skirt the flank of a dome.
- The Domo Puyutano Zone, to the north of the Vetas Hermanas, is characterized by low sulphidation veins in a rhyolitic dome complex. The 86 rock chip samples taken in this zone range from detection to 13.35 ppm Au with an average of 0.519 ppm. The company notes that the high gold values are restricted to a N-S striking vein, the Elizabeth Vein, in the flank of the dome and it strikes towards the Emily Vein to the south.
- The Vetas Ocultas Zone, to the south of the Vetas Hermanas, is physically and stratigraphically higher than the Vetas Hermanas Zone. Veins occur in the form of float and sub-crop which Magna Terra interpret as having cut the underlying andesites below the tuffs and volcanic breccias in which they occur. Gold grade in this zone is spotty with gold ranging from detection up to 0.97 ppm and an average from 68 rock chip samples of 0.095 ppm.
- The Domos de Piedra Negra Zone has grown to an east – west extension of 280 meters of anomalous gold in veins and stockworks hosted in rhyolitic dome material. While the extension of mineralization is generally E-W and N-S in this zone, individual veins strike WNW, which is more typical of the orientation of mineralization in other parts of the Deseado Massif. The 82 samples in this zone have an Au grade from detection to 1.92 ppm and average 0.19 ppm.
Mr. Lew Lawrick, President & CEO of Magna Terra commented: «We are very excited to be enjoying this level of success so early in the program. The veins encountered on the Project have classic low sulphidation textures of the style found at the neighboring Cerro Vanguardia gold mine, which is one of the most important mines in Argentina. The footprint of mineralization is large and with mineralization adjacent to a provincial road, the logistics could not be better.»
All results reported so far are from select samples, and now that the extent of anomalism is defined, the next stage of work will include channel sampling for better definition. Further, the Company is currently undertaking geological mapping and planning for ground magnetic and IP geophysical programs over the discovery area.