Datation par thermoluminescence d'un niveau de Tephra du volcan "TOYA"

Abstract To what extent does the medium, that is to say inscription way and also the dynamics of " reading ", play a significative role to regards the context it takes on in the process of advertising aesthetic behaviours ? Here is the question raised repeatealy in the debate and statements about the theme of digital arts. The characteristics of this new vector, imperative logic, bivalent algebra, langage, electronic flux, affect the arts and stimulate the emergency of new ones. But this influence occurs in the area of meaning and therefore we have to start investigating again first into the meaning of traditional techniques affected by the mutation so as to undestand the compatibility of the format of existing arts is with that of digital art as a medium and as an original form of art. A few assomptions concerning visual arts will be found in this article, where hypothesis of the cognitive impact of art is taken from previous texts and dealt with the light of new facts. A criticism of digital arts reveals the tremendous complexity prevailing in this domain. From the simulation of traditional techniques to the ethical consequences of a bio-symbolical " iconosphère " made real thanks to exhibition, crossing the phenomenal dressing of idealities of the sensitive structure, we are far from reading there the simple theoretical solutions suggested by the software ideology and the supposedly naive denominational binarism

Single grains dating of volcanic quartz from pyroclastic flows using Red TL

The potential benefit of red thermoluminescence (RTL) dating of quartz is related to the signal's stability over time scales of 100 ka to 1 Ma. RTL dating has been tested on volcanic quartz grains in a late Pleistocene pyroclastic flow which erupted from the Toya caldera in Hokkaido, Japan. New TL equipment installed with a small X-ray irradiator facilitated using the regenerative dose method for single grain (or aliquot) for RTL dating. A suitable combination of filters and photomultiplier gave effective RTL readouts while eliminating the black body emission of the heating device. Preliminary examination of the output showed that the new equipment provided RTL signals even from single quartz grains. The RTL signal did not show any sensitivity changes after 10 cycles of reproducibility, making it suitable for a construction of a regenerative dose curve for each grain and aliquot, with no correction for sensitivity changes. The ages resulting from the regenerative dose method are in good agreement with that of a multiple aliquot slide method and approximately concordant with ages estimates based on previous geological evidence