Gatsuurt Geological Setting
The Noyon project exploration licenses and the Boroo Deposit are located within the North Khentei tectonic belt in northcentral Mongolia. This tectonic belt is bounded to the northwest by the Bayangol fault system and to the southeast by the Yeroogol fault system. The North Khentei belt is dominated by three lithotectonic components. The oldest rocks are Late Precambrian to Early Paleozoic flysch sequences which are intruded by later Early Paleozoic intrusive complexes. These rock units are unconformably overlain by Mid- to Upper-Permian continental volcanic rocks and sedimentary rocks that are spatially confined to the Yeroogol fault system. The youngest rock units are Jurassic to Cretaceous and Tertiary coal-bearing sedimentary rocks.
A regional structural zone transecting the Gatsuurt area is the Sujigtei fault, an element of the Yeroogol fault zone. It is a northeasterly trending, high-angle fault system that can be traced for over 200 kilometres along strike. The Sujigtei and Yalbag bedrock gold prospects and numerous placer gold workings occur along the fault system.
In the Gatsuurt area, the Sujigtei fault separates two profoundly differing geologic settings. To the northwest, the bedrock is constituted by Permian felsic volcanic rocks associated with the Dzuun Mod caldera. To the southeast, the Lower Paleozoic clastic metasedimentary rocks of the Kharaa Formation are intruded by intermediate members of the Boroo Intrusive Complex.