11:45 〜 12:00
[L03-05] 資源地球科学の新展開
★招待講演
キーワード：海底鉱物資源、付加体、陸上アナログ、活動的縁辺域、パンサラッサ海、地球化学
Many limestone and clay mines are still actively working in Japan and the self-sufficiency rate for limestone resources is 100%. However, almost all metal mines were closed by the early 2000s except for a few gold mines such as Hishikari Mine in the Kyushu region, leading to a significant shortage of domestic research opportunities in the field of economic geology. In this presentation, I will summarize strengths and weaknesses of Japan in this area and discuss potential future directions for economic geology research.
(1) The Japanese land area is 37.8 km2 and the 61st in the world. However, the total area of territorial waters and Economic Exclusive Zone (EEZ) is 447 km2, which is the 6th largest in the world. Tremendous amounts of seafloor mineral resources such as seafloor hydrothermal deposit, ferromanganese nodule, ferromanganese crust and rare earth element-rich mud are distributed wthin the Japanese EEZ, especially around Minami-Torishima Island, and we would be able to lead this research field in the future (it is difficult to equivalently compete only by using on-land field).
(2) For the on-land research, the greatest advantage of the Japanese Islands is already obtaining a detailed geological map with numerous geochronological data and in-depth tectonic history, as well as vast amounts of petrographic and mineralogical observations / descriptions. The chief weak points are smallness in the scale of mineral deposits and petrographic / mineralogical descriptions of each deposit are sometimes reported only in Japanese.
(3) Since the Japanese Islands are located at the active continental margin and many “types” of mineral deposit are hosted. Moreover, the basement rock of the Japanese Islands is mainly composed of accretionary complexes since ca. 400 Ma, we can unravel the metallogenesis of each deposit type from the aspect of the accretionary geology, especially with a record of pelagic environment of Panthalassa Ocean.
Combining with these Japan’s strengths and the latest methods of petrography and geochemistry, I’m convincing that we would be able to continue to perform a cutting-edge economic geology research in the future.
(1) The Japanese land area is 37.8 km2 and the 61st in the world. However, the total area of territorial waters and Economic Exclusive Zone (EEZ) is 447 km2, which is the 6th largest in the world. Tremendous amounts of seafloor mineral resources such as seafloor hydrothermal deposit, ferromanganese nodule, ferromanganese crust and rare earth element-rich mud are distributed wthin the Japanese EEZ, especially around Minami-Torishima Island, and we would be able to lead this research field in the future (it is difficult to equivalently compete only by using on-land field).
(2) For the on-land research, the greatest advantage of the Japanese Islands is already obtaining a detailed geological map with numerous geochronological data and in-depth tectonic history, as well as vast amounts of petrographic and mineralogical observations / descriptions. The chief weak points are smallness in the scale of mineral deposits and petrographic / mineralogical descriptions of each deposit are sometimes reported only in Japanese.
(3) Since the Japanese Islands are located at the active continental margin and many “types” of mineral deposit are hosted. Moreover, the basement rock of the Japanese Islands is mainly composed of accretionary complexes since ca. 400 Ma, we can unravel the metallogenesis of each deposit type from the aspect of the accretionary geology, especially with a record of pelagic environment of Panthalassa Ocean.
Combining with these Japan’s strengths and the latest methods of petrography and geochemistry, I’m convincing that we would be able to continue to perform a cutting-edge economic geology research in the future.