上総層群飯室層から産出する生痕化石 : 記載及び野外実習教材としての検討上総層群飯室層から産出する生痕化石 : 記載及び野外実習教材としての検討AA12316266 Trace fossils from the Iimuro Formation, Kazusa Group : Systematic descriptions and evaluation for field geology classes
Trace fossils from the Pleistocene Iimuro Formation cropped out in the Komae City, Tokyo, central Japan were studied. Based on our fieldwork, Chondrites isp., cf. Phycosiphon , cf. Skolithos , and an indeterminate trace fossil were recognized in the sandy siltstones of the Iimuro Formation. Although the studied outcrop is generally used for a geological field site geared toward students, invertebrate trace fossils have been paid less attention as studied materials compared with body fossils and mammal footprints. Therefore, in this study, a general learning method focused on invertebrate trace fossils was proposed, and it was applied to the case of Iimuro Formation. As a result, paleoecological diversity and bottom-water redox environment were reconstructed by ichnological analysis of the Iimuro Formation. Furthermore, the ichnological learning method proposed by this study can be applied to other geological field site of the Kazusa Group; therefore, a potential method of field geology class at the outcrop of the Hirayama Formation cropped out in Akishima city was discussed.