Sadajiro Tsuchida (土田 定次郎, Tsuchida Sadajirō,1908-1976) was a Japanese paleontologist and petroleum geologist. He was born in Gifu (岐阜) prefecture, Japan, moved to Sìpíngjiē (四平街, Shiheigai), Manchuria (満州, Mansyū) as a teacher of elementary school, and surveyed in the surrounding area of the city. He moved back to Japan, majored in geology and paleontology at the Tohoku Imperial University (東北帝国大学, Tōhoku teikoku daigaku). After graduation, he moved to Pyongyang (平壌, Pyon-yan), Korea, as an assistant professor and a professor of the mining engineering course at the Taedong Technical college (大同工業専門学校, Daidō kōgyō senmon gakkō). He moved back to Japan again, joined the Teikoku Oil Company (帝国石油株式会社, Teikoku Sekiyu kabushiki-gaisya), Arabian Oil Company (アラビア石油株式会社, Arabia Sekiyu kabushiki-gaisya), and some associated companies, was engaged in oil exploration in some foreign countries. While the period, he gave lectures at Hokkaido University, Niigata University, and Saitama University. He became a professor of petroleum geology (燃料地質学, nenryō chisitsugaku) at Waseda University (早稲田大学, Waseda daigaku) and a researcher (Concurrent post) (兼任研究員) at Waseda Research Institute for Science and Engineering (早稲田大学 理工学研究所, Waseda daigaku rikōgaku kenkyūjo). He died in 1976.
Reading and understanding his 朝鮮鉱床論 (Chōsen Kōshōron, Ore deposits of Chosen (Korea))
朝鮮鉱床論 written by Sadajiro in Showa 19 (1944) , is a compilation of lecture content for students at the Taedong Technical college (大同工業専門学校, Daidō kōgyō senmon gakkō). Its references include reports from various organizations researching the Korean Peninsula at the time, papers submitted to academic journals, etc., and many lines are devoted to citations in the main text. However, as stated in the preface, there are no illustrations included . In addition, it was a time when not only administrative divisions, railway networks, roads, mineral deposits, etc., but also the Japanese language itself (new and old kanji, new and old kana, etc.) were changing. In order to read and understand the book, related materials such as , topographic maps, railway bureau annual reports, gazetteers, atlases, etc. need to be tracked in chronological order.
Fortunately, in recent years, thanks to the efforts of many people, various databases have been developed and made available to the public. We provide multiple links to information that provides the basis for 朝鮮鉱床論 and reference materials to assist in reading, understanding, tracking it, and pointing out its errors. One of Sadajiro's granddaughters/grandsons TK is distributing the Re-edited Edition of 朝鮮鉱床論 (PDF file) with notation.