Geology & Mineralization
The Spring Valley deposit is a large, porphyry hosted gold resource located in the Spring Valley Mining District, Pershing County, Nevada, approximately 20 miles northeast of the town of Lovelock.
Spring Valley is a porphyry/diatreme hosted gold system beneath pediment gravels. Gold occurs along the top of a porphyry intrusion, and in overlying volcanic rocks, at stratigraphic contacts, in fracture zones, and in the remains of a diatreme breccia. Gold mineralization occurs in sheeted quartz veins, hydrothermal breccias, and open fractures over an area 5,200 feet long by 3,500 feet wide that extended to a depth of 1,400 feet. It is commonly found as grains of easily liberated coarse gold. Coarse, easily liberated gold up to 3 mm across shows excellent recovery in metallurgical testing.
A May 2011 updated resource estimate released by Midway reported 2.16 million ounces of gold in the combined Measured and Indicated categories (144.8 million tonnes at a grade of 0.46 gpt Au), plus an additional 1.97 million ounces of gold in the Inferred category (103.9 million tonnes at a grade of 0.59 gpt Au). See table below.
Additional in-fill drilling, metallurgical testing, and mine planning is scheduled in 2013.
Midway – Barrick Joint Venture
The Spring Valley project is a joint venture with Barrick with Barrick earning a 70% interest in the project in 2014. Barrick funded 100% of the costs to earn an interest in this project. Midway may elect to retain a 25% interest and be carried to production by Barrick. This would mean Barrick spends all the monies and Midway would pay back its share of the capital out of 90% of its cash flows from Spring Valley at a rate of prime +2%.
|2014(1)||Measured||Indicated||Measured plus Indicated||Inferred|
|Cutoff (g/t)||Tonnes (‘000s)||(g/t)||Contained ('000 oz)||Tonnes (‘000s)||(g/t)||Contained ('000 oz)||Tonnes (‘000s)||(g/t)||Contained ('000 oz)||Tonnes (‘000s)||(g/t)||Contained ('000 oz)|
Note: The tonnage and total ounces of gold were determined from the statistical block model. Average grades were calculated from the tonnage and total ounces and then rounded to the significant digits shown. Calculations based on this table may differ due to the effect of rounding.
(1) The Mineral Resource Estimate was prepared by Gustavson Associates, LLC (“Gustavson”) of Lakewood, Colorado. The base case estimate uses a cutoff grade of 0.21 g/t. An amended NI 43-101 technical report summarizing the Estimate was filed on January 23, 2015. Gustavson completed the open pit mineral resources, with Zachary Black acting as the Qualified Person.