Comment on “Evidence of humans in North America during the Last Glacial Maximum”

Bennett et al . (Reports, 24 September 2021, p. 1528) report human footprints from Lake Otero, New Mexico, USA ~22,000 years ago. Critical assessment suggests that their radiocarbon chronology may be inaccurate. Reservoir effects may have caused radiocarbon ages to appear thousands of years too old. Independent verification of the ages of the footprint horizons is imperative and is possible through other means.

A multi-proxy Holocene palaeoenvironmental record of climate change and prehistoric human activity from Lough Cullin, southeast Ireland

A multiproxy (pollen, microcharcoal, loss-on-ignition, magnetic susceptibility and geochemistry) sequence from Lough Cullin, southeast Ireland, supported by a high-resolution radiocarbon chronology, modelled using Bayesian approaches, provides a record of environmental change for much of the Holocene. Following the establishment of mixed deciduous woodland, climatic deterioration was likely responsible for pronounced vegetation change and erosion, 7615–6500 cal. BC to 6245–5575 cal. BC, evidence for the ‘8.2 Kyr’ BP climate event. The so-called ‘elm decline’ is dated to 4220–3980 cal. BC and whilst there are possible indications of an anthropogenic cause, clear evidence of woodland clearance with cereal pollen is recorded at 3900–3700 cal. BC, 3790–3580 cal. BC and 3760–3650 cal. BC, during a period of clearance and farming of 320–450 years duration. A reduction in farming/settlement and woodland regeneration during the Middle Neolithic parallels the archaeological record, with low levels of activity during the Late Neolithic/Chalcolithic after 2960–2525 cal. BC, prior to increases during the Bronze Age then woodland clearance and agriculture between 1500–1410 and 1275–1000 cal. BC, corresponding with the archaeological evidence. A subsequent ‘step-wise’ reduction in human activity follows, from the latter date to 815–685 cal. BC, and a brief but pronounced cessation at 690–535 cal. BC. Renewed woodland clearance and agriculture commenced until 415–250 cal. BC. From the latter date until cal. AD 390–540, the Late Iron Age/Early Medieval period, a phase of woodland recovery is attested, followed by renewed landscape disturbance and arable agriculture in particular, continuing to the close of the record at cal. AD 780–1035.

Sosruco Rockshelter: revision of materials of the excavation by S.N. Zamiatnin and the Upper Horizons Radiocarbon Chronology

Recently new investigations of Sosruko site have been conducted. Unfortunately, the materials of the site have not been interpreted in the proper way. The main task of the article is to clarify the origin of stone industries of the Sosruko complexes. We suggest that complexes of the Layers M1 and M2 are related to the Kobuleti Culture of the Transcaucasia. This cultural phenomenon appeared in beginning of the 10th millennium BC as a result of the migration of the carriers of the M’lefaat Culture from the Middle East. Transcaucasia was not the end point of the M’lefaatian migration. Its further expansion resulted to the appearance of the Kukrek Culture in the Steppe zone of Ukraine and Moldova. The common elements of this material culture include the usage of pressing flaking, the presence of bullet-like cores, backed bladelets, bilateral burins, and the sporadic usage of microburin technique for manufacturing of the truncated facetted points. Some of the late materials from the M1 layer are associated with the Darkveti culture of the Transcaucasus. This culture appeared at the beginning of Boreal. The migration of carriers of the Darkveti Culture to Eastern Europe, which started in the 8th millennium BC, led to formation of the Matveev Kurgan and Grebeniki Cultures in the basins of Don, Dnieper, South Bug and Dniester. The common elements of these three cultures are the presence of the flat one- or two-platform monofrontal cores for obtaining the pressing blades and bladelets, symmetric trapezes. The materials from the layers M3 and M4 of Sosruko site demonstrate complete similarity with the Shan-Koba Culture of the Final Pleistocene – Early Holocene. The connection of the Shan-Koba Culture with the Karein B Culture in the South-West of Asia Minor is also considered. We see the similar geometric complexes in both cultures, the presence of low trapezes, symmetric lunates, triangles. Carriers of both cultures use the microburin technique for geometric microliths manufacturing. The migration of the Asia Minor inhabitants began during Bølling interstadial. The migrants reached the Central Caucasus in Allerød. The migration flows at the end of Pleistocene and the beginning of Holocene were the prelude of the Neolithization processes of Eastern Europe and Transcaucasia. The Shan-Kobian migration started a succession of movements of the Near East and Middle East populations to the East Europe and to Caucasus. The migrations of the carriers of the M’lefaat (Kobuleti) and Darkveti cultures led to the appearance of the global zones of informational continuity (Cultural-Historical Regions) in the frames of which the Neolithic innovations were spread in the area. The materials from the Sosruko Grotto give us an opportunity to reveal the chronology of the very beginning phases of the Neolithization in Eastern Europe.

Cosmogenic nuclide exposure age scatter records glacial history and processes in McMurdo Sound, Antarctica

The preservation of cosmogenic nuclides that accumulated during periods of prior exposure but were not subsequently removed by erosion or radioactive decay complicates interpretation of exposure, erosion, and burial ages used for a variety of geomorphological applications. In glacial settings, cold-based, non-erosive glacier ice may fail to remove inventories of inherited nuclides in glacially transported material. As a result, individual exposure ages can vary widely across a single landform (e.g., moraine) and exceed the expected or true depositional age. The surface processes that contribute to inheritance remain poorly understood, thus limiting interpretations of cosmogenic nuclide datasets in glacial environments. Here, we present a compilation of new and previously published exposure ages of multiple lithologies in local Last Glacial Maximum (LGM) and older Pleistocene glacial sediments in the McMurdo Sound region of Antarctica. Unlike most Antarctic exposure chronologies, we are able to compare exposure ages of local LGM sediments directly against an independent radiocarbon chronology of fossil algae from the same sedimentary unit that brackets the age of the local LGM between 12.3 and 19.6 ka. Cosmogenic exposure ages vary by lithology, suggesting that bedrock source and surface processes prior to, during, and after glacial entrainment explain scatter. 10Be exposure ages of quartz in granite, sourced from the base of the stratigraphic section in the Transantarctic Mountains, are scattered but young, suggesting that clasts entrained by sub-glacial plucking can generate reasonable apparent exposure ages. 3He exposure ages of pyroxene in Ferrar Dolerite, which crops out above outlet glaciers in the Transantarctic Mountains, are older, which suggests that clasts initially exposed on cliff faces and glacially entrained by rock fall carry inherited nuclides. 3He exposure ages of olivine in basalt from local volcanic bedrock in the McMurdo Sound region contain many excessively old ages but also have a bimodal distribution with peak probabilities that slightly pre-date and post-date the local LGM; this suggests that glacial clasts from local bedrock record local landscape exposure. With the magnitude and geological processes contributing to age scatter in mind, we examine exposure ages of older glacial sediments deposited by the most extensive ice sheet to inundate McMurdo Sound during the Pleistocene. These results underscore how surface processes operating in the Transantarctic Mountains are expressed in the cosmogenic nuclide inventories held in Antarctic glacial sediments.

Radiocarbon Chronology of Chuzhjajol Culture

Authors summarize and analyze the data on the 14C chronology of the Chuzhjajol culture in the Far northeast of the Europe (the Komi Republic and the Nenets Autonomous Okrug or the basins of the Pechora, Vychegda and Mezen rivers). As a result of the study of dwellings at the sites Vadniur I/7A, Vadniur I/5 and Muchkas, 17 new dates were obtained and its most probable age was determined within the framework of 4th – mid. 3rd millennium BC. These data make possible to attribute more convincingly the earliest manifestations of the Chuzhjajol traditions in the region to the Neolithic, and their further development to the Chalcolithic. However, evidence of metalworking at the sites of this culture has not been identified, and its dynamics is so far expressed only in pottery: the use of natural organic inclusions in clay and the simplification of the design of «lips». This probably indicates a connection with the bearers of porous ceramics of the Garino tradition. It was determined that dwellings of the Vadniur type on the Vychegda and Mezen rivers are the oldest structures in Northern Eurasia with a complex system of ventilation and heating of living space in the form of horizontal channels connected with fireplaces. The materials obtained as a result of the excavation of the basic complexes of the Chuzhjajol culture allows to date those using different materials and to determine the possibilities of using geochronometric methods on the archaeological sites of the taiga zone. The total volume of the obtained information determines the problem of finding the origins of Chuzhjajol traditions of housebuilding, flint knapping and pottery, which are unique for the region under study.

HAZOR EB III CITY ABANDONMENT AND IBA PEOPLE RETURN: RADIOCARBON CHRONOLOGY AND ITS IMPLICATIONS

ABSTRACT Tel Hazor is one of only a few sites in Israel where remains of the Intermediate Bronze Age (IBA) in the second half of the 3rd millennium BC were found on top of Early Bronze III (EB III) city remains. A probe excavation was held at Hazor in 2017 to explore the chronological relation between the EB III and the IBA occupation. The radiocarbon (14C) absolute dates generated from this probe excavation show that following the EB III city demise, the site was abandoned for up to a few hundred years before it was resettled in the IBA. 14C dates obtained from the last level of the EB III city are well before 2500 BCE, fully aligned with the recent “High Chronology” for the EBA in the southern Levant. The excavation also produced dates associated with IBA “Black Wheel-Made Ware” vessels, which were found in large numbers at Hazor.

ABU SALABIKH – ABSOLUTE RADIOCARBON CHRONOLOGY

This article presents a new absolute chronology for the archaeological site of Abu Salabikh, Southern Iraq, during the 4th and 3rd millennia BC. The main goals of this study were to synchronise the sequences of the West and Main Mounds, corroborating the dating schemes based on archaeological and textual finds, and assigning an absolute date to the transition between Uruk and Early Dynastic (ED) periods. Previously published dates and newly produced 14C measurements were used in tandem with Bayesian statistical models to arrive at more precise time estimates. Some inconsistencies in the results point to possible disturbance of the archaeological sequence in the context of tannur kilns and highlight the need for careful sample collection and selection methodology. The results suggest a hiatus in settlement between the Uruk and ED periods c. 3000 BC, and confirm the date of c. 2650-2500 BC for the Early Dynastic ED IIIa Fara-style texts.

Cosmogenic nuclide exposure age scatter in McMurdo Sound, Antarctica records Pleistocene glacial history and processes

The preservation of cosmogenic nuclides that accumulated during periods of prior exposure but were not subsequently removed by erosion or radioactive decay, complicates interpretation of exposure, erosion, and burial ages used for a variety of geomorphological applications. In glacial settings, cold-based, non-erosive glacier ice may fail to remove inventories of inherited nuclides in glacially transported material. As a result, individual exposure ages can vary widely across a single landform (e.g. moraine) and exceed the expected or true depositional age. The surface processes that contribute to inheritance remain poorly understood, thus limiting interpretations of cosmogenic nuclide datasets in glacial environments. Here, we present a compilation of new and previously published exposure ages of multiple lithologies in local Last Glacial Maximum (LGM) and older Pleistocene glacial sediments in McMurdo Sound, Antarctica. Unlike most Antarctic exposure chronologies, we are able to compare exposure ages of local LGM sediments directly against an independent radiocarbon chronology of fossil algae from the same sedimentary unit that brackets the age of the local LGM between 12.3 and 19.6 ka. Cosmogenic exposure ages vary by lithology, suggesting that bedrock source and surface processes prior to, during, and after glacial entrainment explain scatter. 10Be exposure ages of quartz in granite, sourced from the base of the stratigraphic section in the Transantarctic Mountains, are scattered but young, suggesting that clasts entrained by sub-glacial plucking can generate reasonable apparent exposure ages. 3He exposure ages of pyroxene in Ferrar Dolerite, which outcrops above outlet glaciers in the Transantarctic Mountains, are older, which suggests that clasts initially exposed on cliff faces and glacially entrained by rock fall carry inherited nuclides. 3He exposure ages of olivine in basalt from local volcanic bedrock in McMurdo Sound contain many excessively old ages, but also have a bimodal distribution with peak probabilities that slightly pre-date and post-date the local LGM; this suggests that glacial clasts from local bedrock record local landscape exposure. With the magnitude and geological processes contributing to age scatter in mind, we examine exposure ages of older glacial deposits and suggest that the most extensive Pleistocene ice sheet inundated McMurdo Sound during Marine Isotope Stage 8. These results underscore how surface processes operating in the Transantarctic Mountains are expressed in the cosmogenic nuclide inventories held in Antarctic glacial sediments.

Sosruco Rockshelter: revision of materials of the excavation by S.N. Zamiatnin and the Upper Horizons Radiocarbon Chronology

The new radiocarbon dates were obtained from samples of the collections from the excavations by S.N. Zamyatnin in 1955–1957 of the Sosruko Rockshelter in the Elbrus region. The Sosruko Rockshelter is a multi-layered site containing cultural horizons of the Iron Age, Mesolithic and Late Upper Palaeolithic. Clear stratigraphy of the Stone Age layers and representative collections were used to create periodization schemes of the development and change of the lithic industries of the late Pleistocene — early Holocene of the Caucasus. But the lack of radiocarbon dating did not allow determining their absolute age. Three samples of faunal remains of layers M1, M2 and M3 were analyzed. Obtained four radiocarbon AMS dates are in agreement not only with the sequence of deposits in the Rockshelter, but also with the data obtained for similar typological collections of the North-West Caucasus synchronous sites.