The Song elite as well as the members of the noble Liao clans favored different traditions of burial practices and tomb building. The Song elite educated in Confucian classics favored sealed (vertical pit) graves (shuxue tukengmu) not to be walked into over all other types. At the same time the rich landowners and other non-official families of north China continued the Tang dynasty tomb-building tradition and brought single chamber tombs with corbelled domes and architectural wall structures ornamented with wall paintings and reliefs based on the narratives of filial piety and borrowed from Buddhist and Daoist religion and iconography to an unparalleled level in Chinese history. In many tombs evidence is found for geomantic practices, and land deeds (maidiquan) give information about the tomb owner. Commoners were buried in public graveyards or in mass tombs. In Song and Liao times the growing acceptance of Buddhism favored the spread of various types of cremation burials.