Sunday, April 22, 2018

Geology and quaternary environments of the Tategahana Paleolithic site in Nojiri-ko (Lake Nojiri), Nagano, central Japan

Y. Kondo, Y. Takeshita, T. Watanabe, M. Seki, Nojiri-ko Excavation Reserch Group
Quaternary International
Available online 2 January 2018
(Link) available for purchase from ScienceDirect for $36 (US)

Abstract

Excavation of the Tategahana Paleolithic site at Nojiri-ko (Lake Nojiri), central Japan, began in 1962, and the 21st excavation was performed in 2014. The Upper Pleistocene to Holocene fluvio-lacustrin Nojiri-ko Formation is distributed in and around Nojiri-ko. Fossils such as those of Naumann's elephant (Palaeoloxodon naumanni) and Yabe's giant deer (Sinomegaceros yabei), representing the ice age in Japan, have been excavated there in large quantities; at least 46 Naumann's elephants have been found. The fossils have been excavated in strata dating to 37.9–60.4 ka, comparable to MIS 3. Analysis of fossil pollen assemblages indicates that the vegetation at the time was a mixture of coniferous and broad-leaved trees. Bone instruments and spiral flakes made from elephant and deer bones, and stone tools created from stone, not found in the peripheral region, have been excavated from the Nojiri-ko Formation, and concentrated clusters of different types of fossilized elephant bones have been found.

The top horizon containing elephant remains is 37.9 ka old, and thus older than MIS 2 (the Last Glacial Maximum), making it unlikely that Naumann's elephant disappeared from Nojiri-ko only because of climatic cooling. Findings strongly suggest that the occurrence of these large mammal fossils is the result of human activity. The Tategahana Paleolithic site provides important insights into the transitional phase from Asian Paleanthropine to Homo sapiens in Japan.
 
Excepts from the paper:

Archaeological materials

Three horizons have yielded bone flake tools: the U3 unit of the Umibata Sand and Silt Member and the T1 to T3 and T4 units of the Tategahana Sand Member. Typical spiral flakes from the T7 unit of the Tategahana Sand Member were detached from the long bones of S. yabei. These spiral flakes show a higher probability of being the by-product of bone marrow procurement by humans, because a percussion point is evident on the surface of each flake (Ono and Nojiri-ko Excavation Research Group, 1986) (Fig. 8). 

The stone artifacts obtained from the Tategahana excavation site include edge-damaged flakes, a retouched flake, intact flakes, and cores and scrapers.

Three concentrations of large bones, such as the skulls and shoulder blades of P. naumanni, associated with spear-shaped wooden tools and large pebbles have been recognized. This circumstantial evidence emphasizes the likelihood that the site was not a settlement but a butchering or “kill” site. (Ono, 2001, 2004; Ono et al., 2002).

The artifact assemblages obtained from the U3 unit of the Umibata Sand and Silt Member to the T7 unit of the Tategahana Sand Member are distinguished by bone tools and coarse, small, lithic flake tools (Anthropology and Archaeology Research Group for Nojiri-ko Excavation, 2006).


Figure 8, Artefacts from the Tategahana site [with dates]



 Discussion

The question of whether humans lived in the Japanese Islands 40,000 years ago has so far been answered in the negative, based on the results of DNA analyses and anthropological studies using archaeological materials. Izuho and Kaifu (2015) suggest that the UP suddenly emerged in different regions of Japan around 38 ka ago, signaling the arrival of Homo sapiens in this part of eastern Asia.

This time corresponds to the upper age limit of archaeological materials and fossils from the Nojiri-ko Formation. Mitochondrial DNA analyses of the Japanese people have established the existence of various local population groups in the Japanese Islands no more than 40 ka ago (Shinoda, 2015). However, a mammoth kill site discovered in West Siberia was estimated to have an age of 45 ka(Pitulko et al., 2016). This important discovery shows that humans had reached Siberia by that time, and necessitates a DNA-analysis based review of the age of human diffusion. The discovery of moose fossils in the Nojiri-ko Formation indicates that moose moved from Siberia to Honshu Island. The possibility that humans crossed from Siberia to Honshu Island earlier than 45 ka ago is undeniable.

Tsutsumi (2011) notes that it is difficult to judge whether the archaeological materials from the Nojiri-ko Formation are indicative of human activity.

Bone material with a spiral fracture was recently found in the Nojiri-ko excavation and examined by Ono (2001), and the number of spiral flakes found has increased over time (Anthropology and Archaeological Research Group for Nojiri-ko Excavation, 2003). Norton et al. (2009) examined the cut marks on fossils from the Nojiri-ko Formation and determined that hunting had occurred around Nojiri-ko about 40 ka ago. However, Iwase et al. (2015) stated that these conclusions were not based on an accurate examination of other factors that were probably associated with the megafaunal demise. Nevertheless, the Nojiri-ko excavation did reveal that large mammals such as Naumann's elephant moved to Nojiri-ko between the two periods of coldest climate [Marine Isotope Stage (MIS) 4 and MIS 2], and human remains dated to the same time have been excavated from the formation. It is therefore reasonable to hypothesize that large mammals and humans moved to Nojiri-ko when the climate was relatively warm (i.e., in MIS 3). Considering the climate and environment 40 ka ago, it is certainly possible that humans coexisted with large mammals around Nojiri-ko.

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