Wednesday, April 19, 2017

Temporal constraints for the Late Wisconsinan deglaciation of western Canada using eolian dune luminescence chronologies from Alberta

Kennedy Munyikwaa, Tammy M. Rittenour, James K. Feather
Palaeogeography, Palaeoclimatology, Palaeoecology
Volume 470, pages 147-165
15 March 2017
(Link) free
 
Map of the Ice Free Corridor in Northern Alberta, BC, and the Yukon (Canada) between ca. 17 and 15.3 ka
 
Abstract
 
The Laurentide Ice Sheet (LIS) covered most of Canada during the Last Glacial Maximum. Sometime after 20 cal. ka BP, the LIS began to recede from western Canada and, by 11 cal. ka BP, it had retreated from most of the province of Alberta. Due to the scarcity of datable contemporaneous organic materials, the precise timing of the retreat of the ice sheet from the region remains poorly constrained so that the chronology of the sequential positions of the ice sheet margin between 20 and 11 cal. ka BP is largely tentative. In this study, we use luminescence dating of postglacial eolian deposits, sourced primarily from glaciolacustrine and deltaic sediments in central and northern Alberta, to provide an updated chronology for the retreat of the LIS from the region. We examine 14 new and 13 previously published quartz optically stimulated luminescence (OSL) ages, as well as 19 previously published K-feldspar infrared stimulated luminescence ages. The chronologies are used to constrain successive regional ice sheet margin positions that are geomorphically recognizable across the region between 16 and 11 ka (calendar years). These data suggest that the LIS may have retreated from central Alberta earlier than portrayed in radiocarbon derived deglaciation models. We propose that the OSL chronology from postglacial dunes constrains the deglaciation of the region more accurately because luminescence dating does not rely on the development of vegetation to produce material for dating. Implications for the revised chronology include an improved timing of the emergence of an ice-free corridor that may have been used for Paleoindian migration into the Americas as well as enhanced age constraints on when meltwater drainage routes to the Arctic became open in relationship to the Younger Dryas. The chronology could also provide improved constraints for geophysical models that reconstruct regional isostatic rebound which followed deglaciation.

Tuesday, April 18, 2017

Beringia, The Last 65,000 Years

Marnie Dunsmore
4/18/2017

5,000 years ago


















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15,000 Years Ago


















20,000 Years Ago


















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Tolbaga, south of Lake Baikal, Siberia, probably about 35,000 years old.
(Link)

40,000 Years Ago


















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45,000 Years Ago


















Ust'-Ishim, 45,000 years ago in Siberia
(Link)

50,000 Years Ago


















52,500 Years Ago


















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65,000 Years Ago


















References

Similar Meltwater Contributions to Glacial Sea Level Changes from Antarctic and Northern Ice Sheets
Eelco J. Rohling, Robert Marsh, Neil C. Wells, Mark Siddall & Neil R. Edwards
Nature 430, 1016-1021(26 August 2004)
(Link)

Sea Level and Global Ice Volumes From the Last Glacial Maximum to the Holocene
Kurt Lambeck, Hélène Rouby, Anthony Purcell, Yiying Sun, Malcolm Sambridge
PNAS
vol. 111 no. 43
October 28th, 2014
(Link)

Beringia (INSTAAR Simulation)


Similar Meltwater Contributions to Glacial Sea Level Changes from Antarctic and Northern Ice Sheets


FIGURE 1. Comparison of the Red Sea sea level record with Antarctic and Greenland ice-core records and with the timing of both North Atlantic (Heinrich; H) and Southern Ocean (SA) IRD events.

Eelco J. Rohling, Robert Marsh, Neil C. Wells, Mark Siddall & Neil R. Edwards
Nature 430, 1016-1021(26 August 2004)
(Link)

Explanation for the above figure:

a. Sea level reconstruction from the Red Sea method (black dots and line) compared with Antarctic ice-core 18O temperature proxy data (grey) from the BYRD-station ice core (80.0° S, 119.5° W). Error bars indicate 1 standard deviation.

b. As a, but for Greenland Ice Sheet Project 2 (GISP2, 72.6° N, 38.5° W) ice-core 18O (grey). Ice-core data as synchronized to the GISP2 timescale using variations in atmospheric methane concentrations10. Red lines represent three-point (about 500-yr) moving averages of the sea level record, which smoothes inter-sample variability within bounds of the 1 interval ( 5.5 m) that applies to the sea level reconstruction13. Red numbers in a indicate magnitudes of increases in sea level according to the smoothed record, whereas black numbers relate to the unsmoothed data. Inverted triangles in b indicate the occurrence of North Atlantic Heinrich Events H4, H5 and tentatively H6, relative to the GISP2 record8. Italic numbers identify main Dansgaard–Oeschger interstadials 8, 12 and 14. Double-headed arrows illustrate dating differences13 between the original correlation of the Red Sea sea level record to BYRD (as in a) and after tuning to a benthic 18O record12.

c. Schematic representation of intervals of IRD, marked by triangles and SA numbers, as well as intervals with negative 18O shifts in planktonic foraminiferal calcite at 41° and 53° S in the South Atlantic sector. These events were placed within our time frame by graphically transferring the positions of the events relative to the GISP2 18O record as originally reported15. Dashed lines indicate possible correlations to the sea level record. A maximum disagreement is suggested of roughly 1,000 yr, which seems reasonable given the inherent uncertainties in both the sea level chronology (b, and ref. 13) and Southern Ocean records. VSMOW, Vienna Standard Mean Ocean Water.

Monday, April 17, 2017

Divergence Times for Native American vs Siberian Populations

Genomic evidence for the Pleistocene and recent population history of Native Americans
Raghavan et al.
Science
July 21, 2015
(Link)

Supplemental Data Section S7. Timing early Native American migrations (present-day samples) 
Method I: diCal (Demographic Inference using Composite Approximate Likelihood) Analysis 
Method: “Paul and Song (158) developed a principled approach based on the Wright-Fisher diffusion process with recombination to derive improved CSDs directly from the underlying population genetics model.”

Figure S15, shows that all Amerindians (including Athabascan speakers) split from Siberian groups, in this case Koryaks and Nivkhs, approximately 20,000 years ago (with the earliest divergence occurring at approximately 26,000 years ago, and the most recent possible limit on the split occurring approximately 16,000 years ago.) This method suggests a soft split between Siberian and Amerindian groups, starting approximately 26,000 years ago, and continuing over a long time frame of approximately 10,000 years.  The split is statistically complete at approximately 16,000 years ago.

















Beringia


Sea level and global ice volumes from the Last Glacial Maximum to the Holocene



















Abstract

The major cause of sea-level change during ice ages is the exchange of water between ice and ocean and the planet's dynamic response to the changing surface load. Inversion of ∼1,000 observations for the past 35,000 y from localities far from former ice margins has provided new constraints on the fluctuation of ice volume in this interval. Key results are: (i) a rapid final fall in global sea level of ∼40 m in <2,000 y at the onset of the glacial maximum ∼30,000 y before present (30 ka BP); (ii) a slow fall to -134 m from 29 to 21 ka BP with a maximum grounded ice volume of ∼52 × 10(6) km(3) greater than today; (iii) after an initial short duration rapid rise and a short interval of near-constant sea level, the main phase of deglaciation occurred from ∼16.5 ka BP to ∼8.2 ka BP at an average rate of rise of 12 m⋅ka(-1) punctuated by periods of greater, particularly at 14.5-14.0 ka BP at ≥40 mm⋅y(-1) (MWP-1A), and lesser, from 12.5 to 11.5 ka BP (Younger Dryas), rates; (iv) no evidence for a global MWP-1B event at ∼11.3 ka BP; and (v) a progressive decrease in the rate of rise from 8.2 ka to ∼2.5 ka BP, after which ocean volumes remained nearly constant until the renewed sea-level rise at 100-150 y ago, with no evidence of oscillations exceeding ∼15-20 cm in time intervals ≥200 y from 6 to 0.15 ka BP.

Sunday, April 16, 2017

Pleistocene Palaeoart of Asia

Robert G. Bednarik
Arts 2013, 2(2), 46-76
(Link) free

Abstract

This comprehensive overview considers the currently known Pleistocene palaeoart of Asia on a common basis, which suggests that the available data are entirely inadequate to form any cohesive synthesis about this corpus. In comparison to the attention lavished on the corresponding record available from Eurasia’s small western appendage, Europe, it is evident that Pleistocene palaeoart from the rest of the world has been severely neglected. Southern Asia, in particular, holds great promise for the study of early cognitive development of hominins, and yet this potential has remained almost entirely unexplored. Asia is suggested to be the key continent in any global synthesis of ‘art’ origins, emphasising the need for a comprehensive pan-continental research program. This is not just to counter-balance the incredible imbalance in favour of Europe, but to examine the topic of Middle Pleistocene palaeoart development effectively.

Thursday, April 13, 2017

Heiltsuk Deep Connection to Land and Sea



Related Post:

14,000 Year Old Village and Advanced Stone Tools Discovered on Triquet Island, British Columbia
(Link)

Tuesday, April 11, 2017

Story Telling by Eske Willerslev



I am curious to know why Eske Willerslev is so certain that humans could not have lived in a marginal and partially glaciated environment between 26,000 and 12,000 years ago.  First of all, recent papers on the last glaciation in Alberta indicate that the glaciers might have been passable for much of the period between 26,000 and 12,000 years ago (Link).  Secondly, we know that elk and caribou in Europe did not move significantly from their core ranges in Europe during the Last Glacial Maximum (Link).  There is no reason to think that elk and caribou in North American moved out of the regions to the north and south of the Cordilleran-Laurentide glacial conjuncture during the period between 26,000 and 12,000 years ago.  Even today, elk and caribou do inhabit areas directly adjacent to the Canadians Rockies.  There is no reason to think that areas proximate to Alberta, Montana, Eastern British Columbia and the Yukon were not inhabited by elk and caribou for much of the Ice-Age.

The humans that hunted these elk and caribou would also have been living, at least part of the year, in cold climates and could have lived in and traveled through the Cordilleran-Laurentide glacial conjuncture when it was passable.  There is also the possibility that travel was limited to the summer months.

There is now ample evidence that humans were living in cold steppe like climates 24,000 years ago.  For example, humans were living in Lake Baikal, Siberia (Mal'ta Buret' culture) and likely also in the Canadian Yukon at Bluefish caves 24,000 years ago.  Moreover, based on the dating of 13,500 years ago of a horse hunting site at St. Mary's reservoir, Southern Alberta, humans were living at the southern end of the Cordilleran-Laurentide glacial conjuncture 13,500 years ago.

Eske Willerslev states that humans would not have been able to find fuel in the barren landscape of the Southern Alberta tundra during the Ice Age.  What about the Inuit?  They live on the tundra and use animal fat, including caribou fat, as a fuel source, and are not reliant on wood. 

So, in addition to humans living along the West Coast of the Americas more than 14,000 years ago (Monte Verde, Chile and Triquet Island, British Columbia), and at sites such as Cactus Hill, Virginia and Meadowcroft more than 16,000 years ago, it is very likely that humans were also living in steppe and tundra like regions both north and south of the Cordilleran-Laurentide glacial conjuncture.

It is high time that Eske Willerslev thought a little more carefully and stopped preaching about what he thinks humans couldn't do before 12,500 years ago.  Humans had to wait for the "Ice Free" corridor to turn into a boreal forest populated by "moose" in order to inhabit it?  Newsflash:  even today, there are not many moose in dry and windy Southern Alberta.

It is not as if I am suggesting that glacial Alberta 20,000 years ago was widely inhabited, but the notion that is was utterly devoid of humans until "12,500 years ago" is implausible.  Yes, there was a coastal zone off the West Coast of the Americas that enabled human movement.  Nevertheless, to say that was the only way for humans to move into and out of the Americas for 15,000 years is unlikely.

It is unacceptable that Willerslev is using his bully pulpit to enforce notions of human prehistory that are not supported by the evidence.  One of the problems here is that genomic ancient DNA research is done at a handful of elite universities that are tightly coupled with news outlets that quickly publish half baked scientific ideas.

Small cultural anthropology and archaeological teams, geology and paleoecology researchers, and indigenous researchers do not have access to the budget or media machines of these genomic ancient DNA teams.  Our notions of human prehistory are increasingly at the mercy of herd mentality ancient DNA "research".

Reconstructing the confluence zone between Laurentide and Cordilleran ice sheets along the Rocky Mountain Foothills, south-west Alberta

Daniel J. Utting, Nigel Atkinson, Steven Pawley and Stephen J Livingstone
Journal of Quaternary Science
31(7) 769–787
30 August 2016
(Link) available for rent on Readcube for $6.00
(Link) available upon request


Figure:  Patterns of glacial lineations grouped into flowset components, with flowset Stage 1 being the earliest and flowset Stage 3 corresponding to the final glaciation. It is currently not understood as to which glaciation Stage 1 corresponds with, or the age of Stage 1.  The flowset components were given relative ages in the study area based on cross-cutting relationships, discussed in the text.






























Conclusions

We examined the landform record in an area of complex former ice flow within the confluence zone of the Cordilleran and Laurentide ice sheets. The landform record of this area has represented a key line of evidence in recognizing the confluence and mutual deflection of the Late Wisconsinan/Laurentide and Cordilleran ice sheets (Roed, 1975; Bednarski and Smith, 2007), although detailed evidence relating to the build-up, confluence and subsequence desuturing and retreat of these two ice sheets has hitherto remained uncertain.
 
Using a two-pronged approach of flowset interpretation and reconstruction of former proglacial lake extents, we have recognized three distinctive glaciodynamic stages within the fragmentary and overprinted landform record of this area.
 
The earliest of these stages (Stage 1) is identified by flowset components consisting of lineations on the foothills and plains, and on high summits. These landforms are overprinted by younger flow-set components and document a stage of unconstrained flow of Cordilleran ice out onto the Alberta Plains which was significantly more extensive than previously recognized in south-west Alberta. Although establishing the numerical age of this event was beyond the scope of the present study, this finding lends support to other reconstructions in the foothills (Moran, 1986; Bednarski and Smith, 2007) which have previously recognized evidence of an extensive CIS developing before the arrival of the LIS in the region.

The second glaciodynamic stage (Stage 2) relates to Cordilleran ice flowing out of the Athabasca Valley and deflecting to the south-east upon encountering the Laurentide ice. The general pattern of flow identified in this study is broadly similar to that recognized by previous workers, but additional complexities have been revealed based on the examination of high resolution imagery and bare-earth LiDAR imagery. We find evidence that the along-the-mountain-front-flow (FSc-9, 15, 21) moved up into some of the smaller valleys, which suggests that some areas west of this flowset were ice free during this time.

The third glaciodynamic stage is represented by the retreat of ice from the mountain front, which is manifested in the development of a sequence of proglacial lakes created by glacial ice blocking the regional drainage. Localized flow-set components demonstrate that overall ice sheet recession was interrupted by re-advances or surges, such as in the Baptiste River (FSc-14, 16), North Saskatchewan River (FSc-18), Edson (FSc-4) and Obed (FSc-1) areas. All these re-advances are closely associated with proglacial lakes, suggesting the lakes induced instability in the ice sheet.

 The three phases of former ice-sheet flow documented by the geomorphological and proglacial lake extent record represent a framework for further ice sheet reconstruction studies. Another line of research expanding from the current study would be to establish the numerical ages of the flowset components and associated proglacial lake stages within he LIS and CIS interaction zone. Such an approach is essential to more broadly investigate how proglacial lake drainages correspond with deglaciation events, including whether the drainage events involved are sufficient to account for rapid deglacial global sea level rises as invoked by recent ice sheet modelling simulations (Gregoire et al., 2012).

Monday, April 10, 2017

14,000 Year Old Village and Advanced Stone Tools Discovered on Triquet Island, British Columbia



Contrary to what some articles have published about this research, it does not prove that the Americas where "populated" by a coastal root 14,000 years ago.  It simply shows that people with advanced Late Upper Paleolithic tools, and specifically harpoons, were living on Triquet Island 14,000 years ago.  It should be emphasized that people may also have been living in many other places in the Americas.  Hopefully, this research will stimulate other archaeologists investigating sites in the Americas to "dig a little deeper."

Related Post:

A post-glacial sea level hinge on the Central Pacific Coast of Canada
(Link)

Possibly related paper on harpoons (Botovo Culture):

New AMS-dates for the Upper Volga Mesolithic and the origin of microblade technology in Europe
(Link) pdf

Thursday, April 6, 2017

New Indicators of a “(Much) Older-Than-Clovis” Cultural Presence at Chiquihuite Cave Archaeological Site in Zacatecas, Mexico

Ciprian Ardelean
82nd Meeting of the Society of American Archaeology, #140
March 2017
(Link) pdf

Abstract
The systematic search for ancient human presence in the Zacatecas semi-desert of central-northern Mexico continued with new field explorations and excavations during 2016. A new season at the Chiquihuite Cave was meant to verify the weak signals of older-than-Clovis human presence obtained a few years ago. The new extended excavation inside the high-altitude cave revealed two old, clearly differentiated cultural components that had not been acknowledged before. The upper component is clearly laid upon a well-defined occupation floor far away from the entrance, next to the rear walls of the main chamber. It consists mainly of a relatively rich lithic assemblage, while the study of other proxies is under way. It is true that several questions must be made about the assemblage, especially due to its raw material and the technological attributes, but its cultural origin is self-evident. Multiple radiocarbon dates yielded matching results of an age much older than 14,000 cal BP. Another component, much weaker in its characteristics, seems to exist below the upper one, manifested as cultural finds distributed vertically to a considerable depth. Several radiocarbon results suggest an apparent age for the oldest cultural presence going beyond currently accepted dates.

Sunday, April 2, 2017

Alberta Signs Agreement with the Blackfoot


Clement Bear Chief, Siksika, at Blackfoot Crossing



Clement Bear Chief speaks about his memories of Siksika Blackfoot traditional story telling, Okan Ceremony, Natoo'si, his experiences with Catholic Priests when Blackfoot children were forced into residential schools in the 1940s and 1950s, and the suppression of the Blackfoot world view by the residential school.  He speaks at Blackfoot Crossing which is about a one hour drive east of Calgary, Alberta, Canada.