The emergence of microblade industries in the Japanese islands is dated to c. 20,000 bp. with the appearance of microblade industries on Hokkaido earlier than in other parts of Japan.
On Honshu and Kyushu, the oldest dates are c. 17,000-15,000 bp, and their manufacture is associated with a particular strategy of raw material exploitation: The people who manufactured microblade industries, moved exotic lithic materials over long distances and occupied residential camps for short durations.
They had light inventories that suited their high mobility lifestyle as hunter-gatherers.
The period of the microblade industries with wedge-shaped microblade cores in northeastern Honshu is dated to approximately 14,000 BP.
The radiocarbon age of the Araya site (c. 14,000-13,000 BP). calibrated to c. 16,000-17,000 cal. BP (Kitagawawa 2003), is just before the Older Dryas. The succeeding period of bifacial point industries is dated to and after the Older Dryas.
In Origin and spread of microblade technology in Northern Asia and North America, p. 90, chap 5., SANO Katsuhiro in his article “Emergence and Mobility of Microblade Industries in the Japanese Islands” sums up the Paleolithic (through Incipient Jomon period) picture of lithics industries as follows:
“The emergence of microblade industries in the Japanese islands is dated to c. 20,000 BP. This date is in accord with the results of tephrochronology. The appearance of microblade industries on Hokkaido is earlier than in other parts of Japan. On Honshu and Kyushu, the oldest parts of Japan. On Honshu and Kyushu, the oldest dates are c. 17,000-15,000 BP, and these dates are from sites with subconical microblade cores. Wedge-shaped microblade cores spread over northeastern Honshu at c. 14,000 BP, and their manufacture is associated with a particular strategyu of raw material exploitation.
Hominids transported siliceous hard shale as the dominant raw material over a distance of more than 200 km for the manufacture of microblade industries in northeastern Honshu. This raw material was transported to sites in the form of microblade cores, tools, and flake blanks, although the total weight of these artifacts was very small. Limited amounts of local raw materials were introduced to sites in the form of pebbles, roughly prepared cores, and cortical flakes. These raw materials indicate a low degree of diversity.
The people who manufactured microblade industries had only a light set of inventories and exploited lithic raw materials systematically and economically. This strategy of raw material exploitation was advantageous to the highly mobile adaptation of the microblade industries.”
The extreme long distance movement of microblade industries – over 200 km! is said to be a unique characteristic of the Japanese Palaeolithic.
Read further details at Origin and spread of microblade technology in Northern Asia and North America by Sano Katsuhiro. .. .
“These results suggest that humans with microblade industries moved to Hokkaido Island earlier than to other parts of the Japanese islands. … charcoal samples from the Kashiwadai 1 site were recovered from fireplaces associated with lithic concentrations making these dates quite reliable.
The emergence of mciroblade industries in Japan, therefore, dates back to around 20,000 BP based on the evidence from Hokkaido. Hokkaido is the northernmost of the Japanese islands. A landbridge between Hokkaido and the Eurasian continent between Hokkaido and the Eurasian continent existed through Sakhalin island in OIS 2 (Ono 1990). In contrast, the sill depth of the Tsugaru and Tsushima straits between Hokkaido and Honshu and between Korea and Kyushu, respectively, is approximately 130m. This depth is close to the sea level drop during the Last Glacial Maximum (hereafter LGM), and it has been suggested that no landbridge was formed between Hokkaido and Honshu. The landbridge between the Korean Peninsula and Kyushu is estimated to have existed for a very short duration in the LGM (Matsui et al, 1998). This geographical disconnection may have caused the earlier appearance of microblade industries on Hokkaido compared to other parts of the Japanese Islands (Fig. 5.1).
On Hokkaido, the Rankoshi, Togeshita, and Pirika types of microblade cores were recovered below the En-a Tephra (Yamashita 2003; Terasaki and Miyamoto 2003) dated to about 18,000 BP. On the other hand, the Sakkotsu, Shirataki, Oshorokko, and Hirosato microblade core types have not been found below the En-a tephra. It has been argued that the Oshorokko and Hirosato microblade core types are from a later phase because they are found in concentrations with stemmed points that also date to a later phase. Togeshita and Pirika types of microblade cores have also been discovered in sites with the Sakkotsu microblade core type (Obihiro-Akira site), and the radiocarbon date is 10.900+-500 BP (KSU-889) (Sato and Kitazawa 1987).
On Kyushu, it is possible to confirm, the stratigraphic sequence of different types of microblade cores from the Fukui and Senpukuji cave sites. Sugihara (2003) established a chronology in which the Nodake-Yasumiba type (subconical microbladescores) was succeeded by the Funno type (boat-shaped microblade cores) and later by the Fukui type (wedge-shaped microblade cores) on the basis of the stratigraphic and morpho-typological relationship observed at several sites. The appearance of subconincal microblade cores, appear regarded as the oldest phase, is dated to approximately 15,000 BP based on radiocarbon dates from the Chaen site. Subconical microblade cores appear to have been produced in the later phase too. Boat-shaped microblade cores are associated with Incipient Jomon pottery at a number of sites. Additionally, microblade asasemblages have found with arroheads in some sites. This pattern reveals that the microblade industries of Kyushu continued until a later phase than on Honshu.
… a transition from subconical and boatshaped microblade cores to wedge-shaped microblade cores made with the Yubetsu technique, has been established (Suwama1988〕for central Honshu. The relationship between boat-shaped and wedge-shaped microblade cores is not always chronologically distinct, and some researchers have suggested that the knappers of both assmemblage types lived in the same period. At the Yoshioka B site subconical miroblade cores are dated to c. 17,000-14,000 BP. … Wedge-shaped microblade cores have been recovered from under and within the As-YP tephra (Machara and Sekine 1988; Sato and Sano 2002), which is dated to c. 14,000-13,000 BP (Machida and Arai 1992). Considering that the Araya site dates to c. 14,250-13,690 BP (see above), the manufacture of Yubetsu technique wedge-shaped microblade cores in northeastern Honshu possibly emerged about 14,000 BP. …
Studies of the bifaccial point industries have determined that siliceous hard shale was not transported to sites located far from the sources. However, about 10 to 100 exotic varieties of obsidian were recovered from several sites. This, therefore, suggests that humans who manufactured bifacial point industries also moved relatively long distances. They may have acquired raw materials at several locations near the sites because large quantities and varieties of raw materials were abandoned. All these factors make it clear that inhabitants of the bifacial point industries’ sites spent long periods of time exploiting the resources in the vicinity of their sites and that these sites were occupied for longer periods than microblade sites. …
The period of the microblade industries with wedge-shaped microblade cores in northeastern Honshu is dated to approximately 14,000 BP as mentioned above. The radiocarbon age of the Araya site (c. 14,000-13,000 BP). calibrated to c. 16,000-17,000 cal. BO (Kitagawawa 2003), is just before the Older Dryas. The succeeding period of bifacial point industries is dated to and after the Older Dryas. It has been suggested that the transition from microblade industries to bifacial point industries occurred during a climatic amelioration (Nakagawa et al., 2002), with a decrease of the dominant vegetation of conifer forests and a gradual increase of deciduous forests (Tsuji et al., 1985; Tsuji 1997). The extreme long distance movement of microblade industries is a unique characteristic of the Japanese Palaeolithic. One phase of the backed blade industries is dated to around the LGM, and had a transportation strategy more similar to that of the bifacial point industries than to the microblade industries. If the change in mobility from microblade industries to bifacial point industries was caused by a climatic oscillation, it should be confirmed by more environmental and archaeological data.”
— SANO, Katsuhiro, Origin and spread of microblade technology in Northern Asia and North America pp 79-90