GEOCHRONOLOGY LABORATORY
University of Brasília
This facility is part of the Institute of Geosciences of the University of Brasília and is located in 400 m2 of the underground floor of the Science Central Institute building.
The lab was set up with PADCT funds and has been working in routine since 1997.
Hits since 29/11/2001
Sample Preparation
The geochronology laboratory of UnB is equipped with all necessary conventional equipment for sample preparation including two jaw crushers, one disc mill and one pan mill. Heavy mineral concentration is done in a DENSITESTâ table (Photo 1) and magnetic separation is carried out on a magnetic barrier-type Frantz isodynamic magnetic separator (Photo 2). The use of heavy liquids is kept to a minimum.
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Chemistry Rooms.
The laboratory has three clean rooms for U, Pb, Sm, Nd, Rb and Sr chemical extraction. One is used mainly for reagent purification, one is dedicated to Rb-Sr and Sm-Nd work and the third is exclusive to U-Pb analyses. Several class-100 clean air hoods and cleans boxes are available. Reagents are purified in quartz and PTFE stills. Typical Pb blanks for H2O, HCl, HNO3 and HF are between 2-3 pg/mL. Pb loading blanks are < 1 pg. Procedure blanks for Sr and Nd are typically below 50 pg.
Mass Spectrometer
The lab is equipped with a multi-collector (one central and six adjustable Faraday Cups) Finnigan MAT 262 with ion counting. The machine has negative ion capability which will allow Re-Os work in the future.
STAFF
Prof. Elton L. Dantas. – Dr. UNESP, São Paulo. Coordinator
Prof. Reinhardt A. Fuck – Dr. University of São Paulo. Researcher.
Simone Maria Costa Lima Gioia – MSc, chemist. Laboratory manager.
Sérgio Luiz Junges – MSc, geologist. Manager of sample preparation section.
Márcio Ferreira da Silva - Technician.
Francisco Jurandyr de Souza – Technician.
GRADUATE STUDENTS
Danielle Piuzana Fischel – Geochronology of the high-grade Anápolis Itaucu Complex.
Maria Helena B. M. de Holanda – Isotopic studies of subcontinental lithospheric mantle in the Borborema and Tocantins Provinces
Oswaldo Ordoñez Carmona – Geological evolution of the Colombian Central Cordillera
Simone Maria Costa Lima Gioia – Pb isotopes and environmental studies in the Federal District.
Jorge Henrique Laux – Geochronology of the Anicuns-Itaberaí suture zone.
RESEARCH PROJECTS
The geochronology laboratory is involved in several research projects in association with graduate students and fellows of the University of Brasília and other institutions in Brazil and abroad. Some examples are listed below:
1.Geochronology and isotopic studies (Sr, Nd and Pb) of the Goiás Neoproterozoic magmatic arc.
2.Geochronology of high grade metamorphic events in the Itauçu-Anápolis complex using Sm-Nd whole-rock and garnet and U-Pb SHRIMP systematics.
3.Isotopic study of the subcontinental lithospheric mantle in orogenic belts in Brazil: temporal variations and geodynamic implications.
4.Geochronology of gold provinces in Brazil.
5.Origin of the Meso-Cenozoic magmatism of the Colombian Central Andes Cordilleran.
6. Isotopic Investigation of the Indian Pre-Cambrian Carbonatite magmatism
7. Provenance studies of detrital sediments of Brasília and Paraguai Belts using the Sm-Nd method.
8. Archean nucleii in NE Brazil.
9. Isotopic evolution of different terranes in the Neoproterozoic Ribeira Belt, SE Brazil.
10. Crustal evolution of basement rocks of the Brasília Belt.
11. Petrology of Precambrian carbonatites in India.
12.Sr-Nd characteristics of Brazilian kimberlites and associated alkaline complexes.
