The 77th Osaka City Junior High School Science Research Conference (Presentation Division): “Fossil Survey in the Yuasa Formation, Wakayama”

Today (September 13), the conference was held at facilities of Osaka Kyoiku University in Teradachō.
From our school, three projects were nominated for the Presentation Division and nine for the Exhibition Division.
Here is a brief report on one presentation: “Fossil Survey in the Yuasa Formation, Wakayama.”

What the presentation covered
Science Club students reported on four field surveys at Shiraki Beach in Hirogawa Town, Wakayama, where the Yuasa Formation (Early Cretaceous) is exposed. They collected plant, bivalve, and gastropod fossils; cleaned specimens, coated them with a diluted wood-glue solution, and prepared labels specifying the fossil name, locality, formation, geologic age, and date.
Using simple checks—surface color and residue for plant compressions, and a small drop of dilute acid to help confirm shells—they organized the finds and considered what the assemblage says about the past environment. Based on many plant remains together with brackish-water bivalves, they suggested a sequence: vegetation developed on land, then subsidence or sea-level rise led to brackish conditions where bivalves settled and were buried, and later uplift formed today’s shoreline. The team also expressed thanks to Mr. Masaaki Obara (Wakayama Prefectural Museum) for identification guidance and to Mr. Hiroshi Ando (Osaka City Jōtō Junior High School) for field support.

Principal’s reflection
I was impressed by how the students combined careful field safety, specimen care, and straightforward tests to build a clear environmental story. I felt their step-by-step reasoning was easy to follow and educational. In future work, I would like to see them add simple stratigraphic logs and site maps, repeat sampling across seasons, and compare with museum reference collections to make their conclusions even more robust.

Keywords: Hokuryō Junior High School / science research / Yuasa Formation / Wakayama / Shiraki Beach / fossils / plant compression / bivalve / gastropod / field survey / inquiry-based learning

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