2 ms·
The scope of the problem is huge. Oxygen can enter from a highly elaborate network of abandoned mines and boreholes that stretch for miles, as well as any numbe
by alamortsubite 6y ago
The scope of the problem is huge. Oxygen can enter from a highly elaborate network of abandoned mines and boreholes that stretch for miles, as well as any number of surface fissures. As far as the coal component, keep in mind that this region has the highest concentration of anthracite in the world.