Insolation is an important component of meteorological data because solar energy is the primary and direct driver of weather and climate. Previous analyses of cultivated giant clam shells revealed diurnal variation in the Sr/Ca ratio, which might reflect the influence of the daily light cycle. We applied proxy method to sample from prehistoric era, a fossil giant clam shell collected at Ishigaki Island in southern Japan. The specimen was alive during the middle Holocene and thus exposed to the warmest climate after the last glacial period. This bivalve species is known to form a growth line each day, as confirmed by the analysis of the Sr enrichment bands using EPMA and facilitated age-model. We analyzed the Sr/Ca, Mg/Ca and Ba/Ca ratios along the growth axis, measuring a 2-μm spot size at 2-μm interval using NanoSIMS. The Sr/Ca ratios in the winter layers are characterized by a striking diurnal cycle consisting of narrow growth lines with high Sr/Ca ratios and broad growth bands with low Sr/Ca ratios. These variations, which are consistent with those of the cultivated clam shell, indicate the potential for the reconstruction of the variation in solar insolation during the middle Holocene at a multi-hourly resolution.
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http://dx.doi.org/10.1038/srep08734 | DOI Listing |
Environ Monit Assess
January 2025
Sinopec Offshore Oilfield Services Company, Shanghai, 201208, China.
The concentration of trace elements in sediments is a critical element in the quality of nearshore environments. Geochemical background values are the normal concentrations of trace elements in the natural environment, and the use of different background values has resulted in different evaluations. Trace element (Cu, Pb, Zn, Cr, Cd, As, and Hg) concentration profiles along a sediment core were investigated to obtain background values and to assess the depositional processes and contamination levels in Laizhou Bay.
View Article and Find Full Text PDFJ Paleolit Archaeol
July 2024
Laboratory of Theriology, Zoological Institute of the Russian Academy of Sciences, St. Petersburg, Russian Federation.
The Altai mountains contain a number of cave and rockshelter sites that have given crucial information about human evolution in Asia. Most of these caves are located in the Gornyi Altai of Siberia, while the southern flank of the range remains much less known. Bukhtarma Cave was a karstic cave located near the former village of Peshchera, on the banks of the Bukhtarma River running through the foothills of the southern (Kazakh) Altai mountains.
View Article and Find Full Text PDFFront Plant Sci
November 2024
State Key Laboratory of Vegetable Biobreeding, Key Laboratory of Biology and Genetic Improvement of Flower Crops (North China), Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Ministry of Agriculture and Rural Affairs, Beijing, China.
Ecological changes have been observed to promote rates of lineage diversification, yet the precise roles of ecological factors, species evolution, and environmental variability in driving species diversity remain research hot spots. The association between ecological change and lineage diversification, particularly with regard to the size of the time scale, remains poorly understood. To explore whether ecological change facilitates species evolution, we focused on the unique family Paeoniaceae, which encompasses both herbaceous and woody taxa, to investigate the evolutionary rates.
View Article and Find Full Text PDFAm J Biol Anthropol
December 2024
Institute of Archaeological and Paleontological Research of the Pampean Quaternary, Faculty of Social Sciences, National University of the Center of the Province of Buenos Aires (INCUAPA, UNCPBA-CONICET), Olavarría, Buenos Aires, Argentina.
Objectives: Based on the analysis of stable carbon and nitrogen isotopes of bone collagen, stable carbon isotopes of bone apatite and an extensive AMS dating series (~10,000-299 years cal BP), the human paleodiets of 34 individuals from the Central Pampean Dunefields (Argentina, South America) are evaluated.
Materials And Methods: These data are interpreted from the isotopic ecology of animals with archaeofaunal evidence of consumption and isotopic models of human diet. Multivariate carbon and nitrogen stable isotope model and Bayesian stable isotope ellipses were used to interpret human diets.
PLoS One
October 2024
Dipartimento di Scienze dell'Antichità, Sapienza University of Rome, Rome, Italy.
This study investigates botanical remains from the Takarkori site in the Tadrart Acacus region (SW Libya) to reconstruct socio-economic and cultural characteristics of human groups during the Holocene. By analyzing micro- and macrofossils of plant origin, we aim to understand the availability and management of environmental resources and how plant taxa were used by humans. The exceptional preservation of archaeobotanical material across all occupation levels, facilitated by the region's geomorphological and environmental conditions, provides a unique opportunity to study pre-Pastoral and Pastoral Neolithic activities within a comprehensive diachronic framework.
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