Si magic angle spinning (MAS) NMR spectroscopy has been applied for the first time to the structural analysis of ancient glass samples obtained from archaeological excavations. The results show that it is possible to establish the distribution of Si environments in ancient glass by Si MAS NMR, so long as the concentrations of magnetic impurities, such as Mn and Fe oxides, are low. In general, good agreement has been obtained with compositions determined by means of electron probe microanalysis. In addition, the Si MAS NMR data reveal structural differences between glasses manufactured at separate ancient sites.
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http://dx.doi.org/10.1002/chem.201800483 | DOI Listing |
Proc Natl Acad Sci U S A
February 2025
Cultural Heritage Unit, Conservation Services Division, South African National Parks, Pretoria 0002, South Africa.
The rise and spread of ancient Indian Ocean Rim (IOR) trade networks profoundly impacted southern Africa. Control over this trade played a critical role in the rise and maintenance of complex societies of the second millennium CE such as Mapungubwe and Great Zimbabwe. While the African origins of this trade lie in the first millennium CE, understanding its earliest phases and subsequent development in the far south has been hampered by a general paucity of research.
View Article and Find Full Text PDFPLoS One
November 2024
Inter‑Departmental Research Centre for the Study of Cement Materials and Hydraulic Binders (CIRCe), University of Padova, Padua, Italy.
Sci Rep
September 2024
Marine Core Research Institute, Kochi University, Nankoku, 7838502, Japan.
Phosphorus and molybdenum play important roles in the formation of microbial cell structures and specific enzymes crucial for metabolic processes. Nevertheless, questions remain about the preservation of these elements within ancient microfossils. Here, we present shape-accurate ion images capturing phosphorus and molybdenum on Palaeoproterozoic filamentous microfossils by pioneering a methodology using lateral high-resolution secondary ion mass spectrometry.
View Article and Find Full Text PDFScience
September 2024
State Key Laboratory of Lithospheric and Environmental Coevolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China.
There is extensive geologic evidence of ancient volcanic activity on the Moon, but it is unclear how long that volcanism persisted. Magma fountains produce volcanic glasses, which have previously been found in samples of the Moon's surface. We investigated ~3000 glass beads in lunar soil samples collected by the Chang'e-5 mission and identified three as having a volcanic origin on the basis of their textures, chemical compositions, and sulfur isotopes.
View Article and Find Full Text PDFCell
July 2024
The Center for Genome Architecture and Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Center for Theoretical Biological Physics, Rice University, Houston, TX 77030, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA. Electronic address:
Analyses of ancient DNA typically involve sequencing the surviving short oligonucleotides and aligning to genome assemblies from related, modern species. Here, we report that skin from a female woolly mammoth (†Mammuthus primigenius) that died 52,000 years ago retained its ancient genome architecture. We use PaleoHi-C to map chromatin contacts and assemble its genome, yielding 28 chromosome-length scaffolds.
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