World Placer Journal - 2000 - Volume 1, pages 129-133.
Platinum & Gold Placers
of Late Cretaceous and Quaternary age in the Gobi Desert, Mongolia.
Robin Grayson¹, Dr. Baatar Tumenbayar²,
Minjin Batbayar³ &  Baasandorj Altanzul³
(1) General Director of Eco-Minex International Co. Ltd.
(2) Exploration Director of Eco-Minex International Co. Ltd.
(3) Geologists of Eco-Minex International Co. Ltd.

A desk study using satellite images, air photos and ER Mapper 6.0 software predicted palaeoplacers should be present at Altan Uul (‘gold mountain’) in the south Gobi, as it has been a topographic high since at least Jurassic times. An EMI expedition discovered substantial gold-platinum placers of Upper Cretaceous age of economic significance, as well as confirming Quaternary placers. 

Altan Uul mountain was shedding gold and platinum in Cretaceous times as red-bed alluvial fans, and is doing so again.

Active platinum and gold deposition occurs today in wadis as heavy mineral streaks on the top of flash-flood sands, derived from the Upper Cretaceous palaeoplacers undergoing ‘badlands’ erosion. 

Modern erosion of Cretaceous paleoplacers is creating new placers with gold, platinum and black sands. The process may have been operating for several tens of millions of years.

The palaeoplacers are dull red thick conglomeratic fans derived from Altan Uul. Old Chinese placer mines occur in the palaeoplacer as shafts and tunnels. The palaeoplacers are sands and gravels that elsewhere in the Gobi are rich in dinosaur remains. It seems probable that dinosaurs were walking in gold and platinum dust.

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