余庆绿陶陶土地质特征及其开发利用前景

Geologic Features and Exploitation-Utilization Prospect of Yuqing Green Pottery Clay

余庆陶土产于上白垩统扎佐组第二段。作为绿陶原料的岩石,主要是红色的钙质泥岩、钙质粉砂质泥岩和钙质粉砂岩等。因有较为特殊的化学成分和矿物成分,用其烧制的陶件呈现多种绿色,而被命名为“余庆绿陶”。和江苏宜兴、四川荣昌的红陶相比,它不需上釉,不加颜料,并具特有的窑变现象,是一种工艺性能特殊的天然陶泥,有着广泛的开发利用前景。

The Zazuo Formation of Maotai Group of Upper Creataceous in Yuqing intermontane basin belongs to a mountain apron-river-lake facies, whose lithologic change is a bit bigger. According to rock associations, the Zazuo formation can be divided into two members. The first member is grey belt breccia with red complex composition, and the second member is mainly calcilutite and calcisiltite, often with calcic sandstone and breccia embedded. The calcilutite and calcisiltite are pottery clay ore-beds with green pottery clay and their thickness is about 280m. The mineral compositions of the pottery clay are mainly calcite, dolomite, quartz, clay minerals and a small amount of Fe-minerals, feldspar, etc. The chemical compositions are mainly SiO2 (about 4.5%), Al2O3 (about 11%), CaO(about 13%), Fe2O3(about 4.5%), as well as a small amount of Cu, Cr, P, Mn, Sr, Zr, etc., with each composition evenly-distributed, content stable and variation very small. The earthenware made of Yuqing pottery clay doesn't need to be glazed or to be coloured. Under the same sintering condition, different temperatures, flames and kiln positions can make the sintered earthenware have different colours of kiln changes. Thus, with this special craft function, we can produce a lot of earthenware of different colours. Because the earthenware section is green, the earthenware is called 'Yuqing Green Pottery'. As the resource of Yuqing pottery clay is widely distributed, the thickness is big and it can be open exploited, it has a wide exploitation prospect.