US EIA report - Mongolia31 Aug 2018 12:44
"The organic-rich shales of Mongolia are thermally immature near the surface, locally forming combustible oil shale, but reach oil maturity (maximum Ro of 0.8 to 1.0%) in deeper areas ranging from 7,000 to 8,000 ft."
1 feet = 0.305 metres
(7000 to 8000 feet) = 2150 to 2450 metres.
We either hit that already OR in that zone now this weekend.