Mariana Resources (AIM: MARL) said it will shortly begin drilling on the wholly-owned Las Calandrias project, which includes the newly discovered El Nido rhyolite dome complex, in the Santa Cruz province of Argentina. The program follows extensive exploration activity in the area, after the Calandria Sur discovery in late 2009. Recent exploration consisted of detailed mapping, rock chip geochemistry and an Induced Polarization Survey (IP).
“The recently discovered 10sq km Las Calandrias – El Nido dome complex greatly increases the exploration potential of the Las Calandrias project for both high-grade vein and bulk tonnage mineralization”, Mariana Resources MD John Sutcliffe said.
The Las Calandrias Project, which was formerly the Dos Calandrias, has now been extended to include the Calandria Sur and Calandria Norte mineralised rhyolite dome complexes to south-east and the recently discovered El Nido dome complex located to the west. According to Mariana, the 2009 drilling campaign discovered significant disseminated style gold mineralization around the eastern brecciated margin of the Calandria Sur dome. Intersections included 91.5m at 1.6 grams per tonne (gpt) gold and 102m at 1.2gpt.
“The recent IP survey has highlighted some priority concealed targets. An exciting drill campaign is about to start and will follow up the Calandria Sur gold-silver discovery and scout drill selected IP targets elsewhere on the property”, Sutcliffe added said.
Mariana will conduct a minimum of 3,000m of diamond drilling, which primarily designed to follow up the Calandria Sur discovery. Drilling will target down dip extensions, strike extensions, the northern dome margin and the IP anomaly over the centre of the dome. Additionally, IP anomalies at Calandria Norte and El Nido Este will be tested. The company expects the first assay results from the program from mid-April.
The EL Nido rhyolite dome complex consists of several coalescent domes along a northeast trending 3.5×2.5km belt, and it is located 2km west and northwest of the Calandria Sur and Calandria Norte domes. According to Mariana the veins and sulphide breccias identified at the El Nido indicate possible similarities with Calandria Sur. The veins and sulphide breccias were identified at the El Nido Sur, El Nido Norte and the El Nido Centro domes
Mariana said the results of recent reconnaissance rock chip sampling at El Nido Norte is encouraging, with five of thirteen samples assaying above 1.4gpt gold, and up to 2.7gpt gold and 638gpt silver. The company believes that El Nido has the potential to generate new targets for drilling in the next campaign.
The IP survey was conducted by Quantec Geoscience Limited, which carried out a 3D IP and resistivity survey over the mapped rhyolite domes at Las Calandrias. The objective was to detect disseminated sulphide zones at depth and better define rhyolite dome geometry. Sizeable chargeability anomalies were detected within the IP grid at Calandria Sur, Calandria Norte and EL Nido Este which could reflect sulphide mineralisation.
“Sizeable IP anomalies were detected both at Calandrias South and Calandrias North demonstrating moderately elevated chargeabilities … These two IP anomalies demonstrate the probable distribution of sulphides, which accompany mineralization, and provide new information to extend drill targeting”, Quantec’s Senior Geophysicist Miles Rideout commented.
“A narrow structural zone extending 200m further south is also anomalously chargeable and may have mineral potential. Since the Nido Este target is also hosted within rhyolite dome units and shows some evidence of veining at surface. It represents a large probable target of new mineral potential,” he added.
London-based stockbroker FinnCap said it is apparent that the Las Calandrias project’s potential near-surface gold silver mineralisation is greater than it initially thought. The broker said that whilst it is maintaining its 19p per share valuation, it reiterated that it is a very good time to own shares in Mariana, with drilling starting next week and the first batch of results due at the end of April / beginning of May.
The potential for this discovery to become exponentially bigger has become clear, Finncap said. According to the broker, there may appear to be significant grounds to raise its valuation, however it intends wait until the drill results have been realised, before it considers re-valuing Mariana.