%0 Journal Article
%T U-Pb dating by zircon dissolution method using chemical abrasion
%A Takehara
%A Lucy
%A Chemale J¨²nior
%A Farid
%A Hartmann
%A L¨¦o A.
%A Dussin
%A Ivo A.
%A Kawashita
%A Koji
%J Anais da Academia Brasileira de Ci¨ºncias
%D 2012
%I Academia Brasileira de Ci¨ºncias
%R 10.1590/S0001-37652012000200011
%X chemical abrasion was carried out on zircons grains of the temora ii standard for u-pb dating prior to analyses using in situ laser ablation-multicollector ion coupled plasma mass spectrometer (la-icpms) followed by the isotope dissolution thermal ionization mass spectrometer (id-tims) method. the proposed methodology was herein applied in order to reduce primarily the effects of secondary pb loss, the presence of common lead and/or silicate impurities. nine temora ii zircon grains were analyzed by the laser ablation method yielding an age of 418.3¡À4.3 ma. zircon grains of a same population were separated for chemical abrasion before dissolution and mass spectrometry analyses. six fractions of them were separated for isotope dissolution using 235u-205pb mixed spike after we have checked and assured the laboratory conditions of low blank values for total pb of less than 2 pg/g. the obtained u-pb zircon age by the id-tims method was 415.7¡À1.8 ma (error 0.43 %) based on four successful determinations. the results are consistent with the published ages for the temora diorite (temora i a?¡° 416.75¡À1.3 ma; temora ii a?¡° 416.78¡À0.33 ma) and established as 416¡À0.33 ma. the technique is thus recommended for high precision u-pb zircon analyses (error < 1 %), mainly for high resolution stratigraphic studies of phanerozoic sequences.
%K chemical abrasion
%K id-tims
%K la-mc-icpms
%K u-pb dating
%K zircon dissolution.
%U http://www.scielo.br/scielo.php?script=sci_abstract&pid=S0001-37652012000200011&lng=en&nrm=iso&tlng=en