Search results for "Radiometric Dating"
showing 7 items of 27 documents
The Oldest Case of Decapitation in the New World (Lapa do Santo, East-Central Brazil)
2015
We present here evidence for an early Holocene case of decapitation in the New World (Burial 26), found in the rock shelter of Lapa do Santo in 2007. Lapa do Santo is an archaeological site located in the Lagoa Santa karst in east-central Brazil with evidence of human occupation dating as far back as 11.712.7 cal kyBP (95.4% interval). An ultra-filtered AMS age determination on a fragment of the sphenoid provided an age range of 9.19.4 cal kyBP (95.4% interval) for Burial 26. The interment was composed of an articulated cranium, mandible and first six cervical vertebrae. Cut marks with a v-shaped profile were observed in the mandible and sixth cervical vertebra. The right hand was amputated…
Ten years of measured UV Index from the Spanish UVB Radiometric Network.
2013
An analysis is made of the UV Index (UVI) obtained from the ultraviolet erythemal solar radiation (UVER) data measured by the Spanish UVB Radiometric Network between the years 2000 and 2009. Previously, the daily UVI has been evaluated using two different criteria: (a) the value corresponding to solar noon; and (b) the daily maximum value. The mean percentage of agreement is 92% if we consider the cases for which the difference is zero or one UVI unit. These results are similar to those obtained in a previous work where only 2 years were analyzed. In all the stations the UVI reaches very high values (8-10) in spring-summer, and the very high and extreme (≥ 11) UVI values are more dependent …
Environmental radioactivity at Stromboli (Aeolian Islands)
2002
HPGe gamma spectrometry, thermoluminescence dosimetry, X-ray diffractometry and fluorescence techniques have been used to analyze the natural radionuclides content of soil and rock samples, air kerma and geochemical features on the island of Stromboli, belonging to the Aeolian Islands, in the Mediterranean Sea. The 214Bi, 238Ac, and 40K contents obtained are in agreement with the magmatic evolution of the rock formation, as shown by the correlations between radionuclide and chemical elements abundacies, depending on the various magmatic differentiation mechanisms. Correlations between radiometric, lithological and geochemical data have been assessed in order to obtain some hints on the geoc…
The Early Palaeozoic break-up of northern Gondwana, new palaeomagnetic and geochronological data from the Saxothuringian Basin, Germany
2002
Early Palaeozoic volcanic and sedimentary rocks from the Saxothuringian Basin (Franconian Forest, northern Bavaria) have been subjected to detailed radiometric and palaeomagnetic studies in order to determine the tectonic environment and geographic setting in which they were deposited. Two hand samples were collected from the as yet undated pyroclastic flow deposits for 207Pb/206Pb age dating. Radiometric results for these samples, obtained by the single-zircon evaporation technique, are identical within error, and the mean age of all measured grains is 478.2±1.8 Ma (n=11). This age is considered to be primary and firmly constrains the eruption of the ignimbrites and formation of the subaqu…
The triumphal cross of the cathedral of Nevers: painting technique and examination
2019
The large polychrome wooden cross preserved in the Saint-Cyr et Sainte-Julitte cathedral in Nevers was badly damaged during the bombing in July 1944. Restored and put on display on a modern cross in front of the choir, the sculpture suffered a new fall in 2015. The conservation of the work, directed by DRAC-CRMH of Burgundy-Franche-Comté, was preceded by a phase of technical study. Micro-stratigraphic, taxonomic and radiometric analyses and the dendrochronology of the cross were carried out. The dendrochronology of the cross of Nevers and the comparison with radiocarbon dating place the elaboration of the work in the last quarter of the 12th century while confirming the contemporaneousness …
Volcanic products of Lipari (Aeolian islands, Italy): Multivariate analysis of petrographic and radiometric data
2010
Abstract A petrographic and radiometric study, along with statistical multivariate analysis of volcanic products of the island of Lipari (Aeolian islands, Italy) was carried out. The volcanological history of Lipari was reconstructed defining two stages (pre- and post-erosive stages) further on subdivided in four volcanic phases, each of which characterized by products with a particular chemical composition and separated by stratigraphic unconformities. The correlations between petrographic features, determined by X-ray fluorescence, and volcanological history of the island highlight a gradual differentiation with younger rocks showing a more acid chemical composition than the older ones. R…
Environmental Radioactivity and Volcanological Features of Three Islands of the Mediterranean Sea (Pantelleria, Ustica and Vulcano)
1996
Abstract The Mediterranean Sea is an area of great interest for its volcanic activities. This paper presents a comparative study of radiometric and chemical data regarding three volcanic islands located in southern Italy (Pantellena, Ustica, and Vulcano) characterized by different magmatic histories. Measurements of radionulide contents and chemical composition of rock samples belonging to the main lithologies present in the three islands were carried out the observed correlations among radiometric, chemical and mineralogical data reflect the differences in the volcanological genesis and suggest some hypotheses on the magmatic evolution.