Petrology and geochemistry of alkaline rocks

• Grant number: 97/01210-4
• Support Opportunities: Research Projects - Thematic Grants
• Start date: July 01, 1997
• End date: December 31, 2001
• Field of knowledge: Physical Sciences and Mathematics - Geosciences
• Principal Investigator: Celso de Barros Gomes
• Grantee: Celso de Barros Gomes
• Host Institution: Instituto de Geociências (IGC). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Pesquisadores principais: Excelso Ruberti ; Marcia Ernesto ; Wilson Teixeira

Abstract

The present project, with the participation of teachers from the Institute of Geosciences of the University of São Paulo and from other national institutions, in addition to a large number of researchers from abroad, notably from Italian universities, represents the continuity of the research program long established in the Department of Mineralogy and Petrology of that institution, and geared to the investigation of alkaline rocks in their most varied aspects, namely, mineralogical, petrological, geochemical, geochronological and paleomagnetic. The project is characteristically of direct support for research activities, with a small part of the resources aimed at the consolidation of the infrastructure of the Electronic Microprobe Laboratory of the IG-USP. In the first case, the objective is principally to enable field expeditions (covering costs of food and lodging, as well as those connected with the displacement of members of the team), having the most diverse locations as goals of interest, whether in Brazilian or in Paraguayan territory. Equally it is concerned with guaranteeing the continuity of the laboratorial programs (basically, paying the expenses relating to the acquisition of indispensable consumables for the carrying out of analytical works). In the second place, the greatest concern consists of creating operational conditions so that the microprobe can better carry out its functions. To this end, two lines of action are envisaged: a) to guarantee conditions for an effective maintenance work, to be achieved by means of constant evaluation, acquisition and replacement of parts displaying or capable of displaying malfunction problems; b) invest the equipment with the most efficient and agile system of visualization of the samples in the analysis phase. From the scientific point of view, the project will be concerned with the systematic study, both of the different aspects outlined above, of the great number of occurrences of alkaline rocks found in the eastern and western sides of the Paraná Basin, respectively in Brazilian and Paraguayan territory. Additionally to the general program, it is intended also to develop more specific activities focusing on two themes: a) isotopic fractioning (C, O) of carbonatites common to the Brazilian and Paraguayan Mesozoic alkaline provinces and b) tectonic conditioning of the alkaline bodies present in the interior of the Assunção-Sapucai 'rift', in Eastern Paraguay. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

VELAZQUEZ, VICTOR FERNANDEZ; GIANNINI, PAULO CESAR FONSECA; RICCOMINI, CLAUDIO; SALLUN, ALETHEA ERNANDES MARTINS; HACHIRO, JORGE; GOMES, CELSO DE BARROS. Columnar joints in the Patino Formation sandstones, Eastern Paraguay: a dynamic interaction between dyke intrusion, quartz dissolution and cooling-induced fractures. EPISODES, v. 31, n. 3, p. 302-308, SEP 2008. (97/01210-4, 01/10714-3)

ANTONINI‚ P.; COMIN-CHIARAMONTI‚ P.; GOMES‚ CB; CENSI‚ P.; RIFFEL‚ BF; YAMAMOTO‚ E.. The Early Proterozoic carbonatite complex of Angico dos Dias‚ Bahia State‚ Brazil: geochemical and Sr-Nd isotopic evidence for an enriched mantle origin. MINERALOGICAL MAGAZINE, v. 67, n. 5, p. 1039-1057, 2003. (97/01210-4)

GIANBOSCO TRAVERSA; CELSO B. GOMES; PIERO BROTZU; NICOLETTA BURAGLINI; LUCIO MORBIDELLI; MARIA SPERANZA PRINCIPATO; SARA RONCA; EXCELSO RUBERTI. Petrography and mineral chemistry of carbonatites and mica-rich rocks from the Araxá complex (Alto Paranaíba Province, Brazil). Anais da Academia Brasileira de Ciências, v. 73, n. 1, p. 71-98, 2001-03-00. (97/01210-4)