The company is undertaking drilling to upgrade its resource to the indicated and reserve categories as well as refurbishing Theta Hill's processing plant to operational readiness.
Theta Hill is in a world-renowned gold field that has historically produced over 6.7 million ounces of gold.
Theta chairman Bill Guy said Behnken had a proven track record as a South African mine developer, extensive networks within Africa and a strong financial background.
Behnken is a mining engineer and has South African operational experience as the chief executive officer of Tshipi é Ntle Manganese Mining (Pty) Limited during the construction and initial production phase of its Tshipi Borwa Manganese Mine.
Prior to this Behnken was an investment banker with South Africa-based Nedbank and has served as a non-executive director of various mining companies, including the then AIM-listed Gemfields plc.
He is currently the South African representative of Auramet International, a US-based precious metals merchant and mine financier.
Guy said: “Finn and I briefly worked together at Jupiter Mines during a period of strong growth.
“Finn as CEO of Tshipi é Ntle took the mine from commencement to over 500 employees and was involved in all aspects of the project from financing, construction and initial profitable production.
“As a resident of South Africa, mining engineer and banker, Finn’s appointment will further strengthen the board in preparation for the planned development phase of the TGME project in 2019.
“The board now has a more complete and diversified skill set.”
READ: Theta Gold Mines on track for open-cut production from Theta Hill gold project in South Africa
A scoping study for Theta Hill released in mid-October 2018 modelled a 7.6-year, 67,000-ounce-a-year mine operation where 92% of ore is recovered.
Theta Hill’s shallow resource features 4.5 million tonnes at 4.14 g/t for 600,000 ounces.
The updated resource has been estimated within the confines of an open-pit shell with a maximum depth of 100 metres.
Theta Hill mine would take about 10 months to build and 7.4 months to pay back initial capital costs.
Peak capital requirement would be US$16 million, valuing the project at US$152 million, using an after-tax net present value (NPV) calculated with a real 7.5% discount.
The internal rate of return is 132%, with life-of-mine all-in sustaining costs of US$569 an ounce.
The company hopes to make its final investment decision after receiving its feasibility study due in the March 2019 quarter and start building in the June 2019 half, so it can produce gold within nine months.
A map of the historic goldfield that hosts the TGME and Theta Hill gold projects in South Africa