The rocks from the Phu Bo Bit section consist of shale and limestone along with an abundant and diverse invertebrate fauna consisting of brachiopods, corals, bryozoans and crinoids, interpreted as having been deposited in shallow marine or shelf environments. At Phu Bo Bit, thick limestone lenses in shale contain microfossils. Based on the foraminiferan and algae assemblage, the stratigraphic sequence of Phu Bo Bit extends from the late Bashkirian to the early Moscovian. According to lithofacies and palaeontology, the Phu Bo Bit section represents the change from carbonate to siliciclastic sedimentation, which provides new evidence on the marine regression during the mid-Carboniferous.

富博钻头段的岩石由页岩和石灰石组成，以及由腕足动物，珊瑚，苔藓动物和海百合组成的丰富多样的无脊椎动物，被解释为沉积在浅海或陆架环境中。在Phu Bo Bit，页岩中厚厚的石灰岩透镜中含有微化石。基于有孔虫和藻类组合，Phu Bo Bit的地层层序从Bashkirian晚期一直延伸到Moscovian早期。根据岩相和古生物学，Phu Bo Bit剖面代表了从碳酸盐沉积到硅质碎屑沉积的变化，这为石炭纪中期的海洋退缩提供了新的证据。