再论卡以头组

ON KAYITOU FORMATION ONCE AGAIN

“卡以头组”和“卡以头砂页层”两个岩石地层单位关系密切 ,但含义不完全相同。卡以头组名称在首次公开发表时 ,指明标准剖面符合地层规范要求。在多条剖面上卡以头组下部含有原地保存的植物 Gigantopteris和Pecopteris及中生代孢粉化石 ,故卡以头组下部有二叠纪地层 ,卡以头组是一跨二叠纪—三叠纪的岩石地层单位。

Two lithostratigraphic units, the “Kayitou Formation” and the “Kayitou Sandstone Shale Beds”, are closely related to each other but are not entirely the same in their implications. When the name of the Kayitou Formation was made public for the first time, the designated type section conformed the standard of the stratigraphic code. In many sections, the lower part of the Kayitou Formation contains autochthonous plants Gigantopteris and Pecopteris as well as Mesozoic spore pollen fossils. Therefore it is considered that there are Permian rocks in the lower part of the Kayitou Formation, which is the lithostratigraphic unit spanning the Permian Triassic boundary.