Neogene hard clay is widely distributed in the Cenozoic basins of east China, and is the main subject of regional studies of special sedimentary materials for its special properties.

• 上第三系硬粘土在中国东部新生代沉积盆地具有广泛的分布,因其性质复杂而成为中国区域性特殊岩土研究的重要对象。