19003_1979/table1

### Table 1 Geologic Sequence in the Miyakoiima-hokubu district

  |  | Stratigraphy | Thickness (m) | Lithic character
  Holocene | Sand dune deposits | 1～3 | Calcareous sand
  Soil | 1～2 | Clay and sandy clay
  Ikema Terrace Sediment | 0.5～1 | Clay, sand and limestone gravel
  Ōnokoshi Soil | 2～10 | Brown to red clay
  Ryūkyū Group | Shimojishima Limestone | 2～5 | Coral boulder calcirudite and foraminifera calcarenite
  Pleistocene
  Hirara Limestone | 2～8 | Algal ball calcarenite and loose cabonate clastics sandstone
  Tomori Limestone | 10～30 | Alternation of algal calcarenite and foraminifera calcarenite
  Late Miocene | Shimajiri Group Ōkamishima Formation | Pinfudake Mudstone | 150 + | Siltstone with fine sandstone and tuff
  Nanseien Sandstone | 50～70 | Sandstone with siltstone and white tuff
  Nanseien Mudstone | 200～300 | Siltstone with sandstone and bentonic tuff
  Shimajiri Sandstone | 30～50 | Medium sandstone
  Shimajiri Mudstone | 300～500 | Alternation of siltstone and sandstone
  Ōkamishima Sandstone | 200～300 | Pebbly sandstone and coarse sandstone
  Ōkamishima Mudstone | 10～ | Alternation of siltstone and sandy mudstone