Firing temperature determination and thermoluminescence dating of a brick with cuneiform characters found in the ruins of Ancient Babylon

Este artigo tem por objetivo estudar um tijolo com inscrições em caracteres cuneiformes cujas sentenças estão praticamente completas. Estudos tipológicos correspondentes aos relatos históricos sugerem que o tijolo foi manufaturado no século VI a.C., durante a dinastia de Nabucodonosor II, grande monarca da Babilônia. A amostra foi estudada através da difração de raios X (DRX), ressonância paramagnética de elétron (RPE), termoluminescência (TL) e técnicas de análise por ativação instrumental com nêutrons (AAIN). Os resultados demonstraram que o tijolo tem 2350 anos de idade (± 40) e queima menor que 400o C.This paper aims to study a brick with inscriptions in cuneiform characters in  which the sentences are almost complete. Typological studies in agreement with historical records suggest that the tablet was manufactured in the 6th century  BCE during the dynasty of Nebuchadnezzar II, Great King of Babylon. The  sample was studied by X-ray diffraction analysis (XRD), electron paramagnetic resonance (EPR), thermoluminescence (TL), and instrumental neutron activation analysis (INAA) techniques. The results showed that the brick is 2350 years old (± 40) and its firing temperature was lower than 400 °C

Upper Pleistocene deposits of the Comprida Island (São Paulo State) dated by thermoluminescence method

ABSTRACT The Cananéia (Upper Pleistocene) and the Comprida Island (Holocene) formations, outcropping in the Comprida island (SP) have been mapped using geomorphological and lithological criteria. Only one sample of the Cananéia Formation, collected in the homonymous island in front of the Comprida Island, was beyond the limit of the standard radiocarbon method. But since the publication of the geological map of the area in 1978, there has been some doubt on the real occurrence of Pleistocene deposits in southern extremity of Comprida Island. This paper deals with the results of thermoluminescence (TL) ages of eight samples from Comprida Island, which corroborate the Pleistocene age assumed during mapping surveys of these deposits. On the other hand, possible interpretations of the obtained ages, in relation to their depositional environments and related northern hemisphere Quaternary glaciations, are presented

Beta ray induced optically stimulated luminescence properties of calcium oxide phosphor

635-638This work presents the results on optically stimulated luminescence of calcium oxide (CaO). Polycrystalline CaO phosphors are irradiated with beta rays in the dose range 10 – 100 Gy. The optically stimulated luminescence (OSL) from CaO sample is strong, the decay is fast and entire signal decays within 50 s. OSL intensity increases linearly with beta dose. The life time and photo ionization cross section (PICS) of decay are in the range ~0.045, 1.5 and 41.391 s and 1.32x10-16, 3.32x10-18 and 1.42x10-19 cm2 for fast, medium and slow components, respectively. Further, the life time and PICS of fast, medium and slow LM-OSL components have been found to be 2.29, 6.0, 17.0 s and 2.56x10-18, 9.77x10-19, 3.45x10-19 cm2, respectively. Both the OSL curves exhibits general order kinetics

The effect of climate change on the mobility and stability of coastal sand dunes in Ceará State (NE Brazil)

The coast of Ceará State in NE Brazil is covered by vast fields of active and stabilized coastal sand dunes. Its tropical climate is characterized by two seasons, wet and dry, with wind intensity determined by the meridional shift of the Intertropical Convergence Zone. The wind power is negatively correlated with precipitation, and precipitation is negatively correlated with the difference between sea surface temperatures of the tropical Atlantic north and south of the equator. We present a model suggesting that during the Late Pleistocene wind power determined the mobility and stability of the dunes. Sand dunes accumulated during periods of high wind power (as it is today) and stabilized when wind power was low. Once the dunes were stabilized by vegetation they could not be activated even by increased wind power. Samples that were taken for luminescence dating from 25 stabilized dunes along the coasts of Ceará gave ages ranging from135\ua0ka to < 100\ua0yr. We postulate that these luminescence ages fall at the beginning of wet periods in NE Brazil characterized by low wind power. These paleoclimatic wet periods correlate well with the cold periods of stades in Greenland ice-core records

Late Quaternary megafans, fans and fluvio-aeolian interactions in the Bolivian Chaco, Tropical South America

The Chaco is a huge plain and a main biogeographic biome of South America dominated by subtropical semideciduous vegetation that spreads on the Andes footslope onmore than 800,000 km2 through Bolivia, Argentina and Paraguay. The climate is tropicalwet–dry and the South American Summer Monsoon (SASM) leads to intensive convective rainfall during the summer season. Some of the world\u27s largest river–fans such as the Parapeti and Grande rivers megafans developed in the Bolivian Chaco. Our research was based on morpho-sedimentary information and sustained by 25 OSL dating of fluvial and aeolian sediments. We demonstrate that these megafans are bigger than previously postulated by some authors.Morphostratigraphic analysis, geochronological data and regional correlations suggest that the Chaco megafans and large piedmont fans were generated and reached maximum development during the middle pleniglacial and early pleniglacial (ca. 60 to 28 ka) because of the presence of colder andmore seasonal conditions (dry–wet intense contrasting seasons) than those existing today in the Amazon and the Bolivian plains.We suggest that amainmechanism triggering themegafan developmentwas the presence of an intensemonsoonal effect on the Eastern flank of the Andes that enhanced rainfall by orographic excitation during MIS 3 and the early part ofMIS 2 that produced an increase in discharge and sediment supply. Concomitantly to fluvial processes the deflation of fluvial belts occurred and big sand dune fields developed by winds blowing out fromNorth to South following the same pattern the South American lower level jet follows presently. Maximumariditywas reached during MIS 2 with the deposition of loess deposits on the piedmont areas andmegafan surfaces, the continuous generation of aeolian dunes and a remarkable decrease in the fluvial activity. Cold air mass related to the polar advection (friagens or surazos) probably affected the area with more intensity and frequency. The Lateglacial was also arid but probably less extreme than the LGM. During a good part of the Holocene the climatic conditions were still arid to semiarid but became more similar to the present sub-humid climate since ~1.5 ka. During the Holocene, the megafans and aeolian systems didn\u27t reach Late Pleistocene size and level of activity

TL, OSL and C-14 dating results of the sediments and bricks from mummified nuns' grave

This paper presents the results of TL and OSL dating of soil and fragments of bricks from a grave, which was occupied by two mummified nuns, found at "Luz" Monastery, located in the state of São Paulo, Brazil. The TL and OSL ages were compared to C-14 dating ones obtained from bone collagens of the mummies. The majority of the ages is related to the eighteenth century. The gamma-ray spectroscopy was used to evaluate natural radioisotope concentrations in the samples, and by using these concentrations the annual dose rates, from 3.0 to 5.3 Gy/kyr, were obtained. Neutron activation analysis was performed and the radioisotope contents results are in agreement with those obtained by gamma-ray spectroscopy. The contents of U, Th and Ce elements were higher than those found in usual sediments.<br>Este artigo apresenta os resultados de datação por TL e OSL de solos, e fragmentos de tijolos de um túmulo, que foi ocupado por duas freiras mumificadas encontradas no Mosteiro da "Luz", localizado no Estado de São Paulo, Brasil. As idades encontradas por TL e OSL foram comparadas às obtidas a partir de C-14 dos colágenos contidos em amostras de osso das múmias. A maioria das idades obtidas são do século XVIII. A espectroscopia de radiação-gama foi utilizada para avaliar concentrações de radioisótopos naturais nas amostras e para calcular as taxas de dose anual que resultaram em 3,0 a 5,3 Gy/kano. As concentrações radioativas são próximas daquelas obtidas através de Análise por Ativação de Nêutrons. Os conteúdos de elementos U, Th e Ce são superiores aos encontrados na maioria dos sedimentos