EARLY HISTORY OF GEOLOGICAL INVESTIGATION IN JAPAN

The geological investigation of the Japanese Islands was guided by Westerners in the 1860’s, 1870’s, and 1880’s. The Geological Institute of the University of Tokyo was established in 1877 and the Geological Survey Japan in 1878. Benjamin Smith Lyman (1835-1920) from America, Edmund Naumann (1854-1927) from Germany, and a number of other foreign geologists gave distinguished services in the establishing Japanese geology. In the 1880’s most of the foreign geologists returned to their home countries, however, and only Japanese geologists continued the geological research. In 1898, Japanese geologists completed a Geological Map of Japan, on a scale of 1:1,000,000, based on four sheets of 1:400,000 geological reconnaissance maps.

Japanese geologists extended their geological investigations to other Asian countries, as the military landed on foreign soils and colonization proceeded. They finished the geological researches in Taiwan, Korea, Sakhalin, and Manchuria (Northeast China) by the 1930’s. Most famous geological phenomena that named after Japanese researchers were Matuyama Reversed Epoch and Benioff - Wadati zones. Both were investigated around this time.

For discussing the geology of the Japanese island arc, geologists need the geological information of neighboring Asian mainland. So many Japanese geologists were scattered over the Asian Continent to pursue investigations there.

Before 1945, Japanese geologists acquired the information of geology from East Asia, made geological maps and discussed the geology of East Asia. Of course there was no theory of plate tectonics, but the geological maps were mostly accurate.

During the war Japanese geologists had learned from the investigation in Southeast Asia that Dutch geology was technically sophisticated and they got some idea of Dutch method of work. After the War this knowledge was applied for the purpose of studying structural geology and for oil reconnaissance work in Indonesia. In the 1950’s, Japanese geologists were influenced by the works of Dutch geologists as ‘prolegomena’ to plate tectonics.