• Site: Upward Sun River

Upward Sun River is located on a loess-mantled sand dune near the northern scarp of a terrace above the active Tanana River floodplain. Excavations indicate multiple components in over 8 meters of well-stratified aeolian sand and loess deposits. This page provides an overview of work at the site and photos of our ongoing work.

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2006

The site was discovered during a Phase-2 cultural resource management survey. A total of 13 test pits were excavated over four visits. Of these, only 3 were positive for cultural material, including a hearth dating to over 10,000 cal BP.

 Site overview (2006).

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2007

A 16 m2 block excavation was conducted to investigate lower deposits, and an additional 8 test pits were placed across the sand dune. Two lower components were discovered, dating to 12,000 and 13,300 cal BP respectively. Well-preserved faunal remains were found in the lowest component.

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2010

The first year of a NSF-funded project led by Potter consisted of 13 m2 expansion of the earlier excavation area to recover additional samples from the lower components. As part of this work, we placed 4 1x1 meter units across the dune crest to evaluate local geoarchaeology. Within one of these (Block H), we identified a cremation feature. We stopped and continued with the consultation process with local and regional Native groups and it was decided that we could continue. We excavated an additional 17 m2 around this feature and an 8-meter long trench connecting the main excavation with the cremation area. We reported on this find in an 2011 Science article.

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2011

In 2010 we discovered that the cremation was in the central firepit of a residential feature, and conducted additional excavations to explore the entire feature. We excavated 17 m2 in 2011, mainly in the area around the cremation. We conducted very limited lower excavations this year.

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2013-2014

We recently broadened the horizontal scope of the excavations at Upward Sun River to understand the relationship between the residential feature and outdoor hearths identified in previous years. In 2013-2014 we excavated 177 m2 to below the Component 2 depth (~150 cmBS) and tested the lower sediments.

Antler rods from Component 3 (photo courtesy of Ben Potter and Cassidy Phillips)

How old are the USR Infants?

The age of USR Component 3, including all three individuals, the 3-year old cremated child, the 6-week old infant, and the neonate, lies at the transition between the Pleistocene and the Holocene. This transition is referred to as the base of the Holocene as well as the end of the Younger Dryas. This point (an arbitrary estimate within a longer-term climate shift) is not well-dated in some of the ice cores used for periodization, but is officially estimated at 11,700+/-99 years before AD 2000, or 11,650+/-99 cal yr BP using GICC05, yielding a 2-sigma range of 11,848-11,452 cal yr BP. A recent paper (Muscheler et al. 2014 Quaternary Science Reviews (106:81-87)) showed systematic under-counting in the time range of interest, so the estimate is 11,590+/-99 (or 11,788-11,392 cal yr BP).  Global auxiliary stratotypes vary widely, but lie between 12,050-11,200 cal yr BP.

A series of four overlapping radiocarbon assays securely date the Upward Sun River burials to 11,600-11,230 cal yr BP. This overlaps with all of the age estimates for the Pleistocene/Holocene transition. Thus, these specimens date to the Pleistocene-Holocene transition. For brevity, we refer to them as dating to the Terminal Pleistocene given this overlap.

Age estimates of the Pleistocene/Holocene transition

Related Publications

Halfmann, Carrin, Ben A. Potter, Holly J. McKinney, Bruce P. Finney, A. T. Rodrigues, Dongya Y. Yang, and Brian M. Kemp (2015) Early Human use of Salmon in North America at 11,500 years ago. Proceedings of the National Academy of Sciences. Early Edition, September 21, 2015.

Irish, Joel D., Ben A. Potter, and Joshua D. Reuther (2015) An 11,500-year old Human Cremation from Eastern Beringia (Central Alaska). In Analysis of Burned Human Remains, edited by C. W. Schmidt and Steven Symes. Academic Press.

Potter, Ben A., Joel D. Irish, Joshua D. Reuther, and Holly J. McKinney (2014) New Insights into Eastern Beringian Mortuary Behavior: A Terminal Pleistocene Double Infant Burial at Upward Sun River. Proceedings of the National Academy of Sciences. (doi:10.1073/pnas.1413131111)

Reuther, Joshua D. (2013) Late Glacial and Early Holocene Geoarchaeology and Terrestrial Paleoecology in the Lowlands of the Middle Tanana Valley, Subarctic Alaska. PhD dissertation, Univ. of Arizona.

Potter, Ben A., Joel D. Irish, Joshua D. Reuther, Carol Gelvin-Reymiller, and Vance T. Holliday (2011) A Terminal Pleistocene Child Cremation and Residential Structure from Eastern Beringia. Science 331(6020):1058-1062. Supplementary Online Material: pp 1-14.

Potter, Ben A., Joshua D. Reuther, Peter M. Bowers, and Carol Gelvin-Reymiller (2008) Little Delta Dune Site: A Late Pleistocene Multi-component Site in Central Alaska. Current Research in the Pleistocene 25:94-97.

Potter, Ben A., Joshua D. Reuther, Peter M. Bowers, and Carol Gelvin-Reymiller (2007a) Results of the 2007 Phase II Cultural Resource Survey of Proposed Alaska Railroad Northern Rail Extension Routes, Alaska. Prepared for ICF Consulting Services, LLC, by Northern Land Use Research, Inc., Fairbanks. NLUR Technical Report #278d.(276 pages)

Potter, Ben A., Edmund P. Gaines, Peter M. Bowers, and Molly Proue (2007) Results of the 2006 Cultural Resource Survey of Proposed Alaska Railroad Northern Rail Extension Routes and Ancillary Facilities, Alaska. In Two Volumes. Prepared for Surface Transportation Board and ICF, Inc., by Northern Land Use Research, Inc., Fairbanks. NLUR Technical Report #278b-c. (750 pages)

Potter, Ben A. (2005) Site Location Model and Survey Strategy for Cultural Resources in the Alaska Railroad Northern Rail Extension Project Area. Prepared for ICF Consulting Services, LLC, by Northern Land Use Research, Inc., Fairbanks. NLUR Technical Report #278a. (112 pages)