1. Carbonate cement is universally more than 10% in sandstones of the upper Yungang formation in Yungang Grottoes area. It's mainly composed of ferriferous calcite and ferriferous dolomite.
2. Carbonate cement is universally more than 10% in sandstones of the upper Yungang formation in Yungang Grottoes area. It's mainly composed of ferriferous calcite and ferriferous dolomite.
