Pyramid
Project Location

Project Location

Project Overview

Project Overview

View Looking East Towards Ruth Mine Workings

View Looking East Towards Ruth Mine Workings

View Looking South Along Lines of Workings Tested by PYR 9

View Looking South Along Lines of Workings Tested by PYR 9

Alteration Zone

Alteration Zone

Soil Geochemistry

Soil Geochemistry

< >

Pyramid

Navigate page

Other Projects

Introduction

As part of the Company’s strategy to build a new multi-commodity project portfolio, in May 2019 the Company secured exploration rights and an option to purchase a group of claims in the Pyramid Mining District of Nevada. The project is located 25 miles northwest of Reno and is readily accessible from State Highway 445 which crosses the northwest tip of the project.

Project Highlights

Geology & Mineralisation

The Pyramid Mining District lies at the northwest end of the Walker Lane mineral belt a major northwest trending structural deformation zone and a highly productive gold, silver and copper producing region which is host to numerous past and currently producing multi-million ounce epithermal gold deposits as well porphyry copper and porphyry molybdenum deposits.

Within the Pyramid Mining District, the Company’s Pyramid Project is underlain by a thick sequence of mid-late Tertiary age (23 Ma old) rhyolitic tuffs interpreted by the Nevada Bureau of Mines & Geology to have formed within an east-west elongated Caldera structure named the Perry Canyon Caldera.

The gold veins at Pyramid lie within the Perry Canyon Caldera and are interpreted from historical mapping and mineral exploration to lie on the margins of a large and deeply buried porphyry system in the southeast part of the district that is currently claimed by copper producer Asarco LLC (a division part of Groupo Mexico). At the higher erosional levels currently preserved  at Pyramid such porphyry systems are prospective for high-sulphidation gold deposits (in more central areas) such as those found further south in the Walker Lane at the Goldfield Mining District (4 million ounces of past production at 1oz gold/ton) and  low and intermediate-sulphidation epithermal deposits (of which there are many examples in the Walker Lane) in more peripheral areas where the Company’s claims are located. This pattern of mineralisation is similar to that of many large porphyry systems in the US, Peru and the Pacific basin countries.

In the main part of the Pyramid District precious metals were mined from three moderately to steeply dipping, northwest-striking vein systems named after the prominent mines that occur along them - Ruth, Burrus, and Bluebird. The Company’s claim interests cover the Ruth vein system and a number of parallel vein systems and zones of alteration.  In addition to abundant quartz and pyrite, vein minerals in unoxidized ore from the Ruth vein system include barite, anglesite, galena, sphalerite, acanthite, gold, and cassiterite.

Past Mining & Exploration

The Pyramid Mining District was established in 1866 with only small-scale production reported. Modern exploration in the Pyramid district has focussed primarily on the search for porphyry copper mineralisation with only limited exploration having been carried out for gold.

The only documented field exploration in the area of the Company’s claims was carried out by Battle Mountain Gold Mining (“Battle Mountain”) who leased the project from the current lessors, Golden Crescent Corporation, in the period 1988-89. Battle Mountain carried out surface sampling, soil sampling and drilled 10 shallow exploration holes for a total of 1,006m of drilling to depths between 43 and 140m.

Soil sampling was conducted on a 30 x 120m grid within a confined area 600m x 600m centred on Battle Mountain’s main target area, the Ruth Mine vein system and associated vein stockwork. This identified a series of gold-in-soil anomalies and eight of their ten drill holes were designed to test a broad gold anomaly located just northwest of the Ruth Mine. These intersected areas of anomalous gold up to 1.5m grading 1.64 grammes/tonne gold (g/t Au) in hole PYR 1 from 10.7m depth.

Battle Mountain’s two other drill holes were designed to test a parallel vein west of the Ruth vein system which correlates with a separate strong gold-arsenic-mercury soil anomaly, mercury and arsenic being strongly associated with gold in epithermal gold deposits. This soil anomaly is open ended and continues strongly to the northwest southeast boundaries of the sampled area.

Drill hole PYR 9 on this western line intersected high-grade gold mineralisation and visible gold within a sample thickness of 1.52m grading 17.8 g/t Au from 94.5m downhole. A broad zone of low-grade mineralisation continued to the end of the hole at 115.8m where the last 1.52m sample graded 2.6 g/t Au.

PYR 10, targeted the same western line soil anomaly some 150m to the southwest but was interpreted to have been drilled in the wrong direction and made no significant gold intersections.

Battle Mountain did not carry out any follow up exploration.

The Next Step

The association of high-grade gold mineralisation in a previous drill hole associated with a strong and open-ended gold soil anomaly supported strongly by epithermal pathfinder elements mercury and arsenic presents a compelling drill target.

Similar narrow high-grade epithermal gold deposits in Nevada have hosted multi-million-ounce deposits such as the producing Midas Mine where the main veins produced more than 2.2 million ounces of gold and 26.9 million ounces of silver between 1998 and 2013.

Tertiary Minerals intends to follow up Battle Mountain’s drilling and soil sampling results with an initial RC and core drilling programme as soon as possible. Core drilling is recommended as water, which can affect sample quality, was encountered in drilling both holes PYR 9 & 10.

The broader potential of the vein systems on the Project area are highlighted by the results of 43 surface chip samples taken by Battle Mountain from various outcropping veins and old mine workings within the Company’s Project area. These assayed up to 7.27 g/t Au and averaged 1.3 g/t Au.

This high prospectivity was confirmed by surface grab carried out by the Nevada Bureau of Mines & Geology during a regional assessment in 1999 when samples from the 1 km long Ruth vein System averaged 1.3 g/t gold and 131 g/t silver (Garside et.al 2003). The highest gold content, 8 g/t Au, was from the Surefire Mine area which has never been drill tested.