Thomson will remain on the board as a non-executive director.
Chairman Bill Guy said: “Rob has led the company since November 2016 and has seen the company evolve to a potential gold producer with the Theta open-cut project.
“We thank Rob for his efforts and look forward to his continued contribution in a non-executive role."
Project activities continue
The company’s project activities in South Africa continue uninterrupted with the leadership of chief executive officer George Jenkins based at the mine-site.
Theta’s local team is being continuously expanded as the company moves towards the construction phase at the Theta Open Pit Starter Project.
In April the company raised A$930,000 in a share placement with funds to advance the starter project.
The company has received applications for the placement of 4.65 million fully paid ordinary shares at 20 cents per share.
For every two shares subscribed, the applicants will also be issued one listed option exercisable at 30 cents per share on or before October 31, 2020, and one unlisted option exercisable at 40 cents per share on or before April 27, 2022.
The placement will be made under the company’s placement capacity pursuant to ASX Listing Rule 7.1.