Inference of minerals at Redondão kimberlite crater, Parnaíba Basin, Brazil, based on interpretation of airborne gamma-ray spectrometry and ASTER data
Article Sidebar
Main Article Content
Abstract
This work reports how minerals at Redondão kimberlite pipe may be inferred through integrated interpretation of airborne gamma-ray spectrometry data and multispectral images derived from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER). Using several processing techniques (e.g. K, eTh, and eU concentration maps, K/eTh, K/eU, and eU/eTh ratio maps, K image inverse map, profile analysis for radiometric data and; spectral indexes and mineral distribution and abundance maps for ASTER data), it was observed that K concentrations within Redondão kimberlite intrusion are high enough to be distinct from the surroundings and at least three spectral signatures of endmembers extracted from ASTER images suggest that chlorite, diopside, and phlogopite minerals may be present within Redondão kimberlite crater and the near surroundings. Although the sources of K concentrations are unclear, it probably is composed of different minerals and phlogopite may be one of them. The spectral signatures of chlorite, diopside, phlogopite may be derived from clastic materials and products derived from ultramafic mineral weathered, but new studies are recommended to improve distribution and abundance maps of these minerals. These new studies may include hyperspectral sensor images and rock-spectra data. The results reported here be useful for further research whose goal is to map kimberlites using remotely sensed images not only in the study area, but also in other locations with similar geologic context.
Article Details
This work is licensed under a Creative Commons Attribution 4.0 International License.
The papers are published in the open access format, being freely available to any user, under a CC-BY Creative Commons license.
By submitting this manuscript for evaluation, the authors are aware of the CC-BY Creative Commons license. In the case of manuscript approval, the author responsible for the manuscript (corresponding author), hereinafter referred to as CEDENTE (ASSIGNOR), hereby assigns and transfers to CPRM-Serviço Geológico do Brasil, holder of the JGSB, free of charge, on his behalf and on behalf from all co-authors, the right of the first publication. This includes the rights of editing, publication, translation into another language and reproduction by any process, worldwide, today and in the future.
After the first publication by the JGSB, authors hold the copyright without restrictions and are allowed to disclose and distribute their work through personal website pages and institutional repositories.
At the same time, the ASSIGNOR declares that the content of the manuscript is of sole responsibility of the authors and that this content does not infringe the copyrights and/or other property rights of third parties, that is, that any contents of the manuscript and its attachments, if taken from other publications, are duly referenced and, when necessary, the permissions for publications of such contents were requested by the authors from the copyright holders; that the disclosure of images (if any) has been authorized and that it assumes full moral and/or patrimonial responsibility, due to its content, before third parties.