Yuichi Nakazawa

Hokkaido University | Hokudai · Human Evolution Studies

Since its novel invention in 1960, obsidian hydration dating is now recognized as the chronometric method to give dates of archaeological sites, based on measurements of hydration rim thickness. Contrary to the increased awareness of various factors that affect hydration rates and reliability in measurements, the question whether and the extent to...

Although microliths are regarded as small standardized tools for complex composite technology, it is still not fully understood whether this schematic understanding developed in Old World prehistory can apply to the Late Pleistocene microblades in northeastern Asia. Here, referring to the definition of the Old World microliths, we explore the morph...

Despite its long-standing assumption of the spread of early pottery innovated by the Late-Glacial hunter-gatherers in Japan, cultural diffusion as an explanatory model has not explicitly tested. This study addresses the question of the extent to which cultural diffusion played a role in proliferating the innovated early pottery technology across th...

Critical to the survival of island-based human societies is their resilience and adaptation to volcanic hazards. We here evaluate pre-Hispanic (before 15th century AD) land use patterns on the volcanic island of Tenerife, Canary Islands, Spain using obsidian hydration dating (OHD). The samples studied include archaeological artifacts and natural ro...

Scholars have long debated the timing and route by which humans first arrived in the New World. In “Late Upper Paleolithic Occupation at Cooper’s Ferry, Idaho, USA, ~16,000 Years Ago,” published in Science, Loren Davis et al. used radiocarbon dating to establish a chronology for artifacts, and evidence of human activity, that has pushed migration 2...

Archaeologists have long used obsidian hydration dating method to give chronometric dates for obsidian artifacts. Models using these equations independently employ different measurement systems, which are based on rim thicknesses determined by optical microscope and hydrogen depths measured by secondary ion mass spectrometry (SIMS), respectively, a...

To obtain reliable dates for multiple assemblages from a single site, measurements of obsidian hydration rim thicknesses from the flakes of Kyu-Shirataki 3 (northeastern Hokkaido, Japan), a large prehistoric open-air site are evaluated using minimum analytical nodules (MAN). Variations in measured rim thicknesses within the unit of MAN are minimum...

To understand the behavioral significance of the emergence and proliferation of blade technology in the northeastern Asian Upper Paleolithic, this paper explores the function of the earliest blade technology in Hokkaido, northern Japan, through an integrated analysis of edge morphology and use-wears on blade tools from the Last Glacial Maximum (LGM...

To understand the Late Pleistocene human dispersals to the Japanese Archipelago, we examine the paleobathymetric changes in and around the archipelago based on the results of recent paleoclimatological study of the Japan Sea that has provided millennium-scale sea level changes, the Pleistocene mammalian faunal record (e.g., extinct proboscideans),...

This paper reports accelerator radiocarbon dates obtained from 14 charcoal specimens recovered from the Shukubai-Kaso site (Loc. Sankakuyama), which was excavated in 1973. The small flake-based assemblage from the site has been chronologically attributed to represent the oldest archaeological occupation in Hokkaido. Because the new radiocarbon date...

This paper provides a current understanding of human population history in the Pleistocene Japanese Archipelago, particularly with respect to the routes and timing of hunter-gatherer migrations, by incorporating multiple lines of evidence from the records of archaeology, human paleontology, and genetic studies. The human fossil remains are concentr...

The wedge-shaped microblade core technology found along the northern Pacific Rim has been regarded as a trait of hunter-gatherer adaptation during the Late Glacial and initial Holocene. Having recognized variable microblade core reduction methods among the technocomplexes in Hokkaido, by employing an optimization model in lithic technology, the pre...

The Canary Islands are an east trending volcanic archipelago located off the western Atlantic coast of North Africa. Tenerife Island, the largest in the seven island chain, was an active volcanic island formed in an active rift zone punctuated by repeated mountain formation and collapse (Carracedo and Troll, 2013). Volcanic activity on the island s...

Microblade technology was a newly invented technology among modern humans in northeastern Asia during the terminal Pleistocene. Because of its pan-regional distribution, wedge-shaped microblade cores have long been regarded as a cultural marker and a technology critical to debates concerning the peopling of the New World. In Hokkaido, where numerou...

Here we discuss the obsidian raw material procurement of hunter–gatherers at the Upper Palaeolithic site of Ogachi-Kato 2 in Hokkaido, Japan, based on integration of obsidian compositional studies using X-ray Fluorescence and Neutron Activation Analysis, and lithic reduction sequence analysis. Refit analysis reveals three reduction sequences in the...

The effect of the Younger Dryas cold reversal on the survival of Late Glacial hunter-gatherers in the Japanese Archipelago is evaluated, through a synthetic compilation of 14 C dates obtained from excavated Late Glacial and initial Holocene sites (332 14 C dates from 88 sites). The estimated East Asian monsoon intensity and vegetation history based...

In this paper we report on the Last Glacial Maximum (LGM) human occupa-tion at the Kawanishi C site and propose two alternative hypotheses to explain space use based on arrangement of the evident hearth features. Kawanishi C is an open-air site located on the Tokachi Plain, southeastern Hokkaido (Japan) (42° 52′ 50″ N, 143° 11′ 00″ E, ca. 70 m.a.s....

An expansion in archaeological excavations and site identifications over the last 30 years, particularly through an increase in salvage projects and the growth of government archaeology in Japan, has made the Japanese Islands one of the most dense regions of Palaeolithic archaeological sites in East Asia. The history of Pleistocene site discoveries...

In order to better understand modern human behavioral variability in Hokkaido, Japan, we consider the geoarchaeology of the Kamihoronai-Moi site in terms of its geochronology, stratigraphy, depositional environments, and post-depositional disturbances. A Paleolithic component is stratigraphically situated between the Eniwa-a (15,000–17,000 14C yr B...

Stone boiling is one of the principal cooking methods used by hunter-gatherer societies. The present paper proposes behavioral and organizational inferences as to how stone boiling was incorporated into hunter-gatherer subsistence practices through an examination of a shallow-basin hearth in an Early Magdalenian level (c. 15,500 14C B.P.) of El Mir...

In 2004, the Office of Contract Archeology undertook data recovery excavation at the Scorpion site (LA 119530) located on the alluvial fan of Alamo Canyon near Alamogordo, New Mexico. Funded by the U.S. Army Corps of Engineers, Albuquerque District, the excavations were conducted in anticipation of further Alamogordo Flood Control projects. The sit...

This paper reports a recently discovered late-glacial microblade assemblage recovered from the Kamihoronai-Moi site in central Hokkaido, northern Japan. The Kamihoronai-Moi site is situated at the eastern edge of the south-ern Ishikari Lowland in central Hokkaido (42° 47′ 15″ N, 141° 59′ 56″ E; 65.6 m above sea level). The site is on the left bank...

Excavations document the presence of of a late Pueblo I-early Pueblo II fieldhouse, a historic Navajo Camp dating from the 1800s, and a trash midden dating from the late 1800s to modern times. In addition a stone spillway associated with a water detention features possibly used during the military occupation of Fort Wingate in the late 1880s is des...

Over the last three decades, as academic and contract projects have recovered sites attributable to the Last Glacial Maximum (LGM, ca. 20,000–18,000 RCYBP) in Hokkaido, situated between 42° to 46° north latitude, archaeolo-gists have come to realize that those sites have varied assemblages in terms of blank production technologies (methods of core...

Assemblage size, here defined as the amount of artifacts recovered from a single geological layer, has provided a basis for discussing spatial and temporal variation of hunter-gatherer site occupational history and land use (Clark and Straus 1983). In Hokkaido, northern Japan, more than 400 late Pleniglacial sites typologically attributable to the...

In 2006, OCA excavated a small site reflecting a Pueblo IV period Ancestral Puebloan fieldhouse with a nearby Archaic camp located on the West Mesa of Albuquerque. Artifact analysis shows differences in lithic tool manufacture and their use. Contains maps with artifact distributions and artifact illustrations.

Five decades of research history on the late Upper Paleolithic in Hokkaido (northern Japan) shows that microblade assemblages appeared by approximately 20,000 B.P. and that various microbiade technologies were developed during late Pleistocene. The empirically observed good association between the morphological features of lithic raw materials and...

In order to detect the effects of thermally altered obsidian on lithic assemblage, prominent morphological characteristics of obsidian artifacts, which include crazing and breakages, were classified in examining a Meboshigawa 2 assemblage at a late upper Paleolithic site in Hokkaido, northern Japan. Observations made using a light microscope discer...