Green Technology Metals (ASX:GT1) has announced a maiden Mineral Resources Estimate of 4.5Mt at 1.01% lithium oxide and 110ppm tantalum pentoxide over the first 1.5km strike of the McCombe deposit, part of the 20km-wide Root lithium project.

The project is based in northwest Ontario, Canada, and Green Technology Metals says there's significant potential for further Mineral Resource growth along strike and down dip at the McCombe deposit, and across the larger Root project area.

The company also says the Estimate has led to an increase in Mineral Resources to 14.4 million tonnes across two of its 100% owned lithium projects in Ontario.

Green Technology Metals says further diamond drilling will continue in parallel to the current programs running at Morrison and Root Bay.