Research Highlights

Since first conducting my graduate studies at Keio University, I have continued archaeological research on the Japanese archipelago during the Paleolithic period. This type of research has faced a significant challenge since it first began in the late 1940s—soil. Most of the soil covering the Japanese archipelago is acidic volcanic ash soil, which destroys organic remains such as wood and bones, so the only items left to be used in research are stone tools. Elsewhere in the world, it is common practice to conduct research by incorporating artifacts such as wood and bone tools; animal and plant remains of food resources gathered by Paleolithic people; and the human remains of Paleolithic people themselves. Considering this, it is clear that researchers in Japan are at a great disadvantage.

But even under these challenging conditions, there have been several instances where organic matter has been excavated from sites along with other Paleolithic artifacts. Such instances have occurred at sites with peat layers and at lake bottom sites where organic matter is protected from decomposing bacteria due to a sedimentary environment that shields it from the outside air, as well as limestone caves where highly alkaline limestone neutralizes the acidic soil. But sites like these only arise in unique environments, and exploring them is no easy task. What’s more, there was no way for researchers in Japan to avoid the global research trend of attempting to create a comprehensive picture of Paleolithic culture based on excavated materials from across disparate archaeological sites. To help solve this problem, the Keio University Archaeology and Ethnology Laboratory has been conducting ambitious research into cave exploration and excavation in limestone areas since the late 1990s.

These efforts began with the exploration of the Abakuchi and Kaza’ana cave sites in the Kitakami mountains of Iwate Prefecture, and the excavation of the Shitsukari-Abe Cave, located on the Shimokita Peninsula of Aomori Prefecture, is currently underway. Fortunately, the exploration of the Shitsukari-Abe Cave has been successful as Paleolithic artifacts were uncovered four meters below the surface in 2008, confirming that Paleolithic humans had once used the cave. Over the next year, several animal remains were also found, including hare, moose, and brown bear. Although there are approximately 10,000 Paleolithic sites located throughout Japan, there have only been five cases in which stone tools and animal bones were excavated together. This discovery not only provides information on the types of animals hunted by the Paleolithic people of the Japanese archipelago but also offers significant insights into reconstructing the specific methods used to hunt these animals.

(2023/4/1)