A huge slab of the triassic intrusion of the palisade diabase ( also known as tap rock ) broke off these prominent cliffs ( over 300 ft or 90 m high in places ) several days before this picture was snapped .
The purpose of this paper is to explore land reclamation modes that meet the requirements of sustainable development at a region level , which takes zhenggou diabase production area of hunyuan county , shanxi province as example .
