[O-07] Poster presentations by senior high school students

[O07-P31] Proposal of an index for estimating the distance from the source rock

*Ayaka Mitsui¹, *Reiji Iwamoto¹, *Keishi Okumi¹, *Mayu Naito¹, *Yamato Yasuhara¹, *Natsuki Yamamoto¹, *Naoko Kodama¹, *Akito Sasaki¹, *Akira Tada¹, *Takuto Nakanou¹, *Tomohiko Maeda¹, *Yuya Muromoto¹, *Ryusei Moriyama¹ (1.Hyogo Prefectural Himejihigashi Senior High School)

Keywords:Ibo River , FU value, volume ratio of quartz / feldspar, source rock

The volume ratio of quartz / feldspar was calculated from the quartz and feldspar of the Ibo River flowing in the southwestern part of Hyogo prefecture.

In the Ibo River basin, the average grain sizes of quartz and feldspar are almost the same. The FU value of quartz does not change much, but the FU value of feldspar increases downstream because feldspar melts very quickly. The volume ratio y of quartz / feldspar to the distance x from the source rock is indicated by an approximate straight line of y = 0.024x + 0.58. These show that the distance from the source rock can be estimated mathematically. Everyone intuitively knows that the particles are rounder and the quartz / feldspar is larger toward the downstream, but this study showed that it can be expressed by an equation for the first time.