'urn burial' , clay container 甕棺葬, 粘土容器

Impressive: Archaeologists have discovered a group of 2,000-year-old tombs using a unqiue ancient burial method in China

Chinese experts discover 113 ancient human remains buried in household clay containers | Daily Mail Online
http://www.dailymail.co.uk/news/peoplesdaily/article-3830847/Mystery-2-000-year-old-tombs-Chinese-experts-discover-113-ancient-human-remains-buried-household-clay-containers.html

瓮棺葬_百度百科

瓮棺葬（urn burial）

Clay - Wikipedia, the free encyclopedia

黏土