Keywords:Cambrian Hitachi Volcano Plutonic Complex, Kanayama Limestone, Fossil/Fossil-like texture, Archaeocyathus, Echinodermata, trace fossils
The Cambrian Hitachi Volcano-Plutonic Complex (CHVPC) widely occurs in the Hitachi district of the southern Abukuma Mountains. The Akazawa Formation characterized with volcanic rock beds is a member of the CHVPC, and contains the Kanayama Limestone Member. The CHVPC recrystallized to the amphibolite to greenschist facies rocks. The Kanayama limestone crystallized obviously to marble, so that it is difficult to observe a detailed texture of fossil. However, we found many fossil/fossil-like textures from the Kanayama limestone. We report some textures of Archaeocyathus, Coral, spines of Echinodermata or Arthropoda, Brachiopoda, Sponge and trace fossils from this limestone bed. The Kanayama Limestone is very likely a Cambrian formation; therefore, the described fossil textures are the oldest one in Japan.