%0 Journal Article
%T Correla£¿£¿o gamaespectrom¨¦trica de afloramentos e po£¿os: estudo de caso na Forma£¿£¿o Ponta Grossa (Bacia do Paran¨¢, Brasil)
%A Ferreira
%A Francisco Jos¨¦ Fonseca
%A Candido
%A Ary Gustavo
%A Rostirolla
%A Sidnei Pires
%J Revista Brasileira de Geof¨ªsica
%D 2010
%I Scientific Electronic Library Online
%R 10.1590/S0102-261X2010000300005
%X in analogue modeling, ground gamma-ray spectrometric data of the devonian jaguaria¨ªva, tibagi, and s£¿o domingos members of the ponta grossa formation (paran¨¢ basin) allowed for a better understanding of the spatial distribution of lithotypes. correlations based on gamma-ray values obtained from deep well logging could be improved. ground values, spaced 50 cm in sandstones and 100 cm in shales, were taken along four sections: arapoti, tibagi, jaguaria¨ªva, and ponta grossa. the sections were 30, 250, 12, and 16 meters thickness, respectively. the results show that both ground and deep values reflect the gradual clay enrichment trend noticed along the arapoti section (transition beds between furnas and ponta grossa formations). along the tibagi section (jaguaria¨ªva member), total organic carbon values are in direct relation to ground and deep gamma-ray values, and good gamma-ray spectrometric and granulometric correspondence is observed between both deep and ground data along 250 meters of ponta grossa formation outcrops. along the jaguaria¨ªva section, clear decrease of intensity is observed in sandy layers, with abruptly lower values at the contacts with basal sandstones of the itarar¨¦ group. along the ponta grossa section, the tibagi member, with its notably higher sand-fraction content, shows a gamma-ray signature compatible with the coarsening upward observed in well data. the s£¿o domingos member, a massive clayey interval of the ponta grossa formation, is characterized by high gamma-ray values in both investigation levels. ground gamma-ray spectrometry combined with detailed outcropdescriptions and deep source data proved to be useful in the establishment of analogue models for the ponta grossa formation in the paran¨¢ basin.
%K ground gamma-ray
%K gamma-ray well logging
%K analogue models
%K ponta grossa formation
%K paran¨¢ basin.
%U http://www.scielo.br/scielo.php?script=sci_abstract&pid=S0102-261X2010000300005&lng=en&nrm=iso&tlng=en