Thirty-two radiocarbon ages on bone, charcoal, and carbonized plant remains from 10 Clovis sites range from 11,110 ± 40 to 10,820 ± 10 C years before the present (yr B.P.). These radiocarbon ages provide a maximum calibrated (cal) age range for Clovis of ~13,050 to ~12,750 cal yr B.P. This radiocarbon record suggests that Clovis first appeared at the end of the Allerød and is one of at least three contemporary archaeological complexes in the Western Hemisphere during the terminal Pleistocene. Stemmed projectile points in western North America are coeval and even older than Clovis, and the Fishtail point complex is well established in the southern cone of South America by ~12,900 cal yr B.P. Clovis disappeared ~12,750 cal yr B.P. at the beginning of the Younger Dryas, coincident with the extinction of the remaining North American megafauna (Proboscideans) and the appearance of multiple North American regional archaeological complexes.
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http://dx.doi.org/10.1126/sciadv.aaz0455 | DOI Listing |
Proc Natl Acad Sci U S A
January 2025
Archaeology & Palaeoecology, School of Natural and Built Environment, Queen's University, Belfast BT9 3AZ, United Kingdom.
Polar ice cores and historical records evidence a large-magnitude volcanic eruption in 1831 CE. This event was estimated to have injected ~13 Tg of sulfur (S) into the stratosphere which produced various atmospheric optical phenomena and led to Northern Hemisphere climate cooling of ~1 °C. The source of this volcanic event remains enigmatic, though one hypothesis has linked it to a modest phreatomagmatic eruption of Ferdinandea in the Strait of Sicily, which may have emitted additional S through magma-crust interactions with evaporite rocks.
View Article and Find Full Text PDFPLoS One
December 2024
German Mummy Project, Reiss-Engelhorn-Museen, Mannheim, Germany.
In accordance with ancient Egyptian beliefs, the preservation of the body after death was an important prerequisite for the continued existence of the deceased in the afterlife. This involved application of various physical interventions and magical rituals to the corpse. Computed tomography (CT), as the gold-standard technology in the field of paleoradiology, enables deeper insights into details of artificial body preservation.
View Article and Find Full Text PDFNew Phytol
February 2025
Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, 86011, USA.
The tusk of the male narwhal is a prolonged canine tooth, reaching a size of up to 3 m in length. The tusk erupts through the young narwhal's upper left lip and, over time, develops into an elongated structure composed of dentine growth layers with an outer coating of cementum. In this study, we utilized bomb radiocarbon (C) to estimate the ages of three narwhal tusks, which allowed us to validate the assumption that one growth layer is deposited annually in narwhal tusks.
View Article and Find Full Text PDFGlob Chang Biol
October 2024
Soil Sciences Section, Institute of Earth System Sciences, Leibniz University, Hannover, Germany.
Understanding the fate of organic carbon in thawed permafrost is crucial for predicting climate feedback. While minerals and microbial necromass are known to play crucial roles in the long-term stability of organic carbon in subsoils, their exact influence on carbon persistence in Arctic permafrost remains uncertain. Our study, combining radiocarbon dating and biomarker analyses, showed that soil organic carbon in Alaskan permafrost had millennial-scale radiocarbon ages and contained only 10%-15% microbial necromass carbon, significantly lower than the global average of ~30%-60%.
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