From time to time reference has been made to the nearby Omai mining operation as a sort of example of what is possible in this particular part of the Guyana Shield. I thought I'd see what I could find out about it.
It seems that the mine operated for 13 years until 2006 and in that time it produced 3.7m oz at an average 1.4g/t. It was closed down for over a year in the early 90's when its tailing dam broke. It consisted of two main pits and 70% of its gold was extracted using cyanide. It was run mainly and then entirely by the Canadian company, Cambior, which was subsequent to the mine's closure, taken over by IAMGOLD. Here is a short description of the area's geology provided by the company.
"The Omai mine consists of two distinct deposits. The Fennell deposit is centered on a small 400-meter diameter quartz diorite intrusive. Free gold mineralization is associated with shallow dipping quartz-carbonate veins with thicknesses varying from a few millimeters to1.5 meters. Main veins also extend a few hundred meters into the surrounding volcanics and carry significant mineralization.
The 1.8-kilomtre long Wenot deposit consists of a series of narrow bands of felsic tuff associated with east-west trending, steeply dipping shear zones. Gold mineralization is closely associated with these felsic units.
Both deposits feature a laterite and saprolite weathering cover of up to 75 meters showing the same geological characteristics as the underlying hard rock."
I'm not sure how that compares to our Hicks and Smarts mines - Omai seems to sit on the same shear as they do - or the Ohio Creek prospect - different shear. What is clear is that Omai was put together as a low grade (average over mine life of 1.4g/t) high volume (Omai plant could handle at least 4 times the amount of material as our Karouni plant) operation compared to both Smarts / Hicks which averages over 2g/t. It seems that Troy may be thinking along similar lines to that of kojak in that to begin with at least they will mine small areas of high grade material (I'm guessing that is what they are looking at - the bridge they intend to put in does not appear designed for constant sustained heavy traffic).
Here is the webpage I got most of this info from.
http://web.archive.org/web/20050315144101/www.cambior.com/site/english/operations/operations/fr_omai.htm
Also, it seems that in 2017 another Canadian outfit, Maydia Gold Guyana, moved to re-open Omai, claiming that there was still multi-million ounce deposits yet to be mined.
https://www.kaieteurnewsonline.com/2017/11/28/omai-gold-mine-ready-for-us500m-investment-660-permanent-jobs/
