There are two major distributions of high-quality cryptocrystalline lithic raw materials in northern Japan: obsidian resources in the south-east Paleo-Sakhalin-Hokkaido-Kurile Peninsula (Izuho & Sato 2007) (Figure 2), and siliceous shale widely distributed in the south-west Paleo-Sakhalin-Hokkaido-Kurile Peninsula and in the north of Paleo-Honshu Island (Yamada 2006; Sano 2007).
High-quality non-local cryptocrystalline raw materials, including obsidian and siliceous shale, are prevalent in each industry.
Many of the small flake industry sites are characterised by short-term occupations coupled with the intensive use of local lithic raw materials such as obsidian gravels and siliceous shale.
Standardised blade points, on the other hand, were made only from high-quality raw materials, such as siliceous shale, and only on limited occasions when sites were located near a source of raw material.
The blade-point industry is distributed throughout Paleo-Honshu Island, and it is particularly dense in areas where siliceous shale occurs.
The sequence of black siliceous shale
and carbonate that extends from about 11,900 to 11,870 feet is questionably assigned to the Frame Member of the Wristen Formation.
Most tanged points were made from siliceous shale or tuff, which was the most widely used raw material in Late Palaeolithic central and southern Korea.
Obsidian and siliceous shale (tuff) arrowheads are also reported from the top horizon at Hwadae-ri (Choi & Ryu 2005).
They are made of porphyry flakes rather than siliceous shale or tuff blades.
Since the technology involves producing very small artefacts with standardised shapes, it requires delicate control in flaking and relatively high quality raw materials such as siliceous shale and obsidian that are often nonlocal to many parts of the Korean Peninsula.
Assemblage Absolutedate (BP) * Tanged point Hwadae-ri 31 200 [+ or -] 900 3 Porphyry points, 30 000 [+ or -] 1700 BC relatively large (OSL) size Hopyeong- 27 600 [+ or -] 300 Siliceous shale dong 27 500 [+ or -] 300 points with 29 200 [+ or -] 900 broken tip 31 200 [+ or -] 900 Yongho- 38 500 [+ or -] 1000 2 (one each from dong upper and lower horizons) Yongsan- 24 430 [+ or -] 870 37 siliceous shale dong (19 310 [+ or -] 790) point, broken tips, bases Gorye-ri 7 siliceous shale points Assemblage Other artefacts Source Hwadae-ri Blades, vein quartz Choi & Ryu 2005 scrapers, awl Hopyeong- Blades Hong & Kononenko 2005 dong Yongho- Denticulates, Han 2002 dong ground stone Yongsan- Blades, blade cores Kim 2004 dong Gorye-ri Large blades, crested Seo et al.
The remaining part of the Rhuddanian and Aeronian succession, the Zelkovice Formation, is composed of organic-rich black shales, siliceous shales