Prime Meridian completes alteration study at Tango.
Prime Meridian Resources Corp. (TSXV:PMR) has completed the alteration study of the porphyry target at the company’s Tango gold/silver/porphyry project in southern Sinaloa state, Mexico. The News Release of 3 July 2019 described data for 941 rock samples. These well-studied samples represent control points that allowed the Company to better interpret geochemical and observational data from soil sample sites and additional rock sample sites. There are now a total of 4578 surface points with alteration assemblages classified as described in Table 1. Summary distribution statistics for geochemical analyses are in Table 2. A map is in Figure 1.
Alteration mapping of the Property using field observations, conventional rock and soil geochemistry, microscopy, magnetic susceptibility measurements and XRF geochemistry shows that a partially sericite altered magnetite-biotite shell of “M2” veinlets daylights on surface at elevations of 350-550 meters, centered just north of Picachos, is circular in shape, and has a diameter of about 2.3 kilometers. Based on estimates from Pacey (2016), this shell can range from 100 to 500 meters thick, is typically closer to 200 meters thick, and surrounds and caps deeper potassic assemblages dominated by potash feldspar. At Picachos, only 9 samples were dominated by K-feldspar, so it is likely that this assemblage and the principal porphyry ore zone is mainly below surface on the Tango Property. Copper geochemistry of soil samples overlying the porphyry are subdued, mainly because the overlapping sericitic alteration contains pyrite that generates sulfuric acid in the weathering environment on surface, and has leached the copper from any near-surface chalcopyrite or bornite. To find copper in the field, an XRF gun was used to identify anomalous values in near-surface rock, usually where sulfide was encapsulated in quartz veinlets, and excavations were dug into bedrock using picks and shovels. Usually some brochantite (copper sulfate) could be found on fracture surfaces about 1 meter into the rock.
Little geological traversing has been done on the deep sericitic cover surrounding the magnetite-biotite shell. Copper values in soil and rock samples from these areas are low for the reasons mentioned above, and decent rock exposure usually has to be made with heavy tools. Some traverses are warranted for the purpose of mapping the limonite to see if some of this is hematite from weathering of chalcocite.
Table 1. Alteration assemblages inferred from observational and geochemical data on the Tango Property
Table 2. Compiled summary distribution statistics for element concentrations measured from 3929 soil and rock pulps using Group 1DX, Group 1F15, fire assay and hand-held XRF methods (see below and NR dated 3 July 2019 for analytical method descriptions). 75th, 90th, 95thand 98th are percentiles. Gold* lab analyses are available for 2916 samples as data from the hand-held XRF are not reliable for gold and are not used. Elements such as K, Ca, Mg and others will be under-estimated in lab analyses as aqua regia digestion of sample pulp is incomplete. Nonetheless, the data were helpful for classifying the alteration assemblages.
Alteration map of the Tango Property. Voroni polygons of the survey points were used to illustrate the alteration assemblages. Most of the porphyry-style mineralization is overprinted by sericitic alteration (peach). Porphyry veinlets that are exposed on surface are mainly “M2” magnetite-biotite veinlets (potassic-ferric alteration in pink) that form a shell 2.3 km in diameter (black dotted circle) around and above a potassic ore zone that is probably below surface.
Sampling and Analytical Procedures
Rock sampling procedures were described in a News Release dated 3 July 2019. Soil samples mentioned in this News Release were collected on pre-planned sample grids at either 25 meter spacing or 50 meter spacing. If the planned site did not have suitable material, the site was either moved a few meters, or eliminated. Line spacing ranged from 400 meters to 100 meters. The sample site was cleaned of debris using a machete or shovel, and the top layer of organics was removed. A small pit was dug with a rock hammer or shovel and about 1 kg of mineral soil was collected. Roughly every 20 samples, blind standards and blanks were inserted into the sample stream. Sample notes included the co-ordinates of the site, colour of the sample, local bedrock type, local mineralization type and geologic structure.
The samples were shipped to Acme Laboratories (now Bureau Veritas) preparation facility in Guadalajara via courier. At the lab, the samples were dried at 60 degrees Celsius, then disintegrated and sieved to -80 mesh. Prepared pulps were couriered via DHL Express to the lab in Vancouver, Canada. A 15 gram charge from each pulp was dissolved in hot aqua regia and analysed for gold and base metals using combined ICP-MS methods (Group 1DX or 1F15). Samples with more than 10000 ppb Au were re-analysed using fire assay methods. ACME has a quality system compliant with the International Standards Organization (ISO) 9001 Model for Quality Assurance and ISO/IEC 17025 General Requirements for the Competence of Testing and Calibration Laboratories. They ran duplicate pulp analyses, as well as control materials internal to the lab. All QA/QC data has been checked and is preserved in the MxDeposit database.
Aqua-regia is a weak digestion, and results are partial for most elements.
The scientific and technical information in this news release has been prepared in accordance with the Canadian regulatory requirements set out in National Instrument 43-101 (Standards of Disclosure for Mineral Projects) and reviewed and approved on behalf of the Company by Michelle Robinson, MASc. P.Eng. a Qualified Person as defined by NI-43-101.
The Company is currently conducting a non-brokered private placement financing of up to 15,000,000 units at a price of ten cents ($0.10) per unit to raise proceeds of up to $1,500,000. Each unit consists of one common share and one common share purchase warrant (the “Warrants”) with each Warrant entitling the holder to acquire one additional common share at a price of thirty cents ($0.30) per share for twelve months from closing. The Warrants will be subject to the right of the Company to accelerate the exercise of the Warrants if the shares of the Company trade at or above $0.50 for a period of 10 consecutive trading days.
Finders fees may be payable on this financing and are payable on the Tango Project transaction.
Final approval from the TSX Venture Exchange for the Tango Project is subject to submission of a Title Opinion on the project (pending) and the closing of a financing to meet the financial obligations of the project and the working capital needs of the Company for six months.