GEOCHEMICAL MAPPING BASED ON REGULARLY SPACED COMPOSITE STREAM SEDIMENT SAMPLES PRODUCED FROM STORED ALIQUOTS - STATE OF PARANÁ PRE-CAMBRIAN SHIELD, BRAZIL
A collection of 6,587 active stream sediment samples covering about 4,800 km² in the Paraná Shield, southern Brazil was used to produce 75 composite samples each representing a 5’ x 5’ cell. The original samples were retrieved from the archives of the Geological Service of Paraná - MINEROPAR and the Geological Service of Brazil - SGB / CPRM. The composite samples were submitted to four analytical methods with the determination of 66 elements. Geochemical maps of the isolated elements along with bivariate correlation analysis showed six associations between elements, each representing specific lithologies and at least one area with high exploratory potential, which was previously unknown given the small amount of elements analyzed in the original samples. The geochemical maps were produced either by cell classification (pixel maps) or by the application of the minimum curvature interpolation method, considered as the best interpolator for the generation of the isograd maps (vector maps). The comparison between composite and original samples showed that, even with different analytical techniques, the element contents of the composite samples are similar to the average of the contents in the original samples on each cell. The results obtained allow us to recommend the adoption of this set of procedures in stream sediment sample collections covering large areas, with at least three advantages of: (a) eliminating field costs by retrieving already collected and archived samples, (b) reducing the amount of samples to be analyzed and (c) minimize any positioning errors of sampling sites collected before the advent of GPS equipment. The verification and detailing of the areas of interest evidenced by this procedure can be done easily with the analysis of the original samples still stored in the collections.
Copyright Transfer Statement
The copyright to this article is transferred to Sociedade Brasileira de Geoquímica effective if and when the article is accepted for publication. The author(s) warrant(s) that his/her/their contribution is original and that he/she/they has/have full power to make this grant. The author(s) sign(s) for and accept(s) responsibility for releasing this material The copyright transfer covers the exclusive right and license to reproduce, publish, distribute and archive the article in all forms and media of expression now known or developed in the future, including reprints, translations, photographic reproductions, electronic form (offline, online) or any other reproductions of similar nature.
Author(s) may self-archive an author-created version of his/her/their article on his/her/their own website and or in his/her/their institutional repository. He/she/they may also deposit this version on his/her/their funder’s or funder’s designated repository at the funder’s request or as a result of a legal obligation, provided it is not made publicly available until 12 months after official publication. Author(s) may not use the publisher’s PDF version, which is posted on www.geobrasiliensis.com.br, in repositories. Furthermore, the author(s) may only post his/her/their version provided acknowledgement is given to the original source of publication, assigning the link where it can be found. This link must be accompanied by the following text: “The final publication is available at www.geobrasiliensis.com.br”.
The author(s) retain(s) the right to use his/her/their article for his/her/their further scientific career by including the final article published by Geochimica Brasiliensis in other publications such as dissertations, theses and postdoctoral qualifications provided acknowledgement is given to the original source of publication.
After submission of the agreement signed by the corresponding author(s), changes of authorship or in the order of the authors listed will not be accepted by Sociedade Brasileira de Geoquímica.
Title of article:
Place and Date: