DES PEOPLE

Head of Earth Sciences

Room 213 Steele Building
Tel:
+61 7 3365 3001 (office)
+61 7 3365 7454 (lab)
Fax: +61 7 3365 1277
Email: Paulo Vasconcelos

Principal research interests:
Supergene enrichment in ore deposits.
Isotopic dating of weathering processes.
Exploration geochemistry.
Palaeoclimatology and landscape evolution.
Application of K-Ar and ⁴⁰Ar/³⁹Ar and noble gas systematics to ore deposit genesis.
Origin and geochemistry of gem deposits.

Current Projects:
Weathering Geochronology, apatite fission track, and U-Th/He thermochronology: implications to Landscape Evolution in SE Brazil
Weathering Geochronology and ¹⁰Be and ²⁶Al erosion rate measurements: implications to Landscape Evolution in the Pilbara Craton
Weathering Geochronology and ¹⁰Be and ²⁶Al erosion rate measurements: implications to Landscape Evolution in the Mount Isa Region
Weathering Geochronology and Landscape Evolution in the Borborema Province, NE Brazil
Weathering Geochronology and Landscape Evolution in South China
Weathering Geochronology, Landscape Evolution, and Nickel Laterite Evolution in New Caledonia
Mechanisms and timing of silicification in Australia and the genesis of opal deposits
Cenozoic Magmatism in NE Brazil
Cenozoic Volcanism in SE Queensland
Mesozoic and Cenozoic Magmatism in SE Brazil
U-He, ⁴⁰Ar/³⁹Ar, and Re-Os as fingerprints of metal sources in orogenic gold deposits
U-Th/He dating of iron and manganese oxides
Cosmogenic ³He generation and retention in goethite and hematite
Hydrothermal vs. supergene origin of orebodies in banded iron formations in the Hamersley iron province
Hydrothermal vs. supergene origin of orebodies in banded iron formations in the Quadrilátero Ferrífero iron province
Hydrothermal vs. supergene origin of orebodies in banded iron formations in the Carajás iron province
Supergene Enrichment in the Kalahari Manganese Fields, South Africa
Timing of topaz and emerald mineralization in the Quadrilátero Ferrífero, Minas Gerais, Brazil
Timing and mechanisms of gold mineralization in the Borborema province, NE Brazil
⁴⁰Ar/³⁹Ar geocronological constraints on postulated hominid fossil sites in Cueva Victoria, Spain
Tracing possible sources for Chapada Diamantina diamonds and carbonados
Timing of Pb-Zn mineralization in the Chapada Diamantina
Timing and duration of gold mineralization under continental transtensional regime: ⁴⁰Ar/³⁹Ar constraints on the Jiaodong gold province, east China

Recent Publications:

2005
Vasconcelos P. 40Ar/39Ar Geochronology of Celadonite: Insights into the Weathering History of the Paraná Continental Flood Basalts. Geochim. Cosmochim. Acta, submitted.
Heim, J. Vasconcelos P., Farley K. and Shuster D. Dating palaeochannel iron ore by (U-Th)/He analysis of supergene goethite, Hamersley Province, Australia. Geology, submitted.
Zhou M.-F., Yan D.-P., Vasconcelos P.M., Li Y., Hu R.-Z. 40Ar/39Ar Geochronological constraints on the tectono-thermal evolution of the Danba domal terrane along the Eastern margin of the Tibetan plateau, Western China. GSA Bulletin, submitted.
Vinasco, C.J., Cordani, U.G., and Vasconcelos, P. Application of the 40Ar/39Ar methodology in the study of tectonic reactivations of shear zones: Romeral fault system in the Central Cordillera of Colombia. Journal of South America Earth Sciences,, submitted.
Carmo I.O. and Vasconcelos P. 40Ar/39Ar Geochronology Constraints on Late Miocene Weathering Rates in Minas Gerais, Brazil. Earth Planet. Sci. Lett, in press.
Spier C.A., Vasconcelos P., and Oliveira, S.M. 40Ar/39Ar Geochronology and the Evolution of Lateritic Iron Deposits in the Quadrilátero Ferrífero, Minas Gerais, Brazil. Chemical Geol., in press.
Araújo, M. N. C., Vasconcelos, P. M., Silva, F.C.A., Jardim de Sá, E.F., and Sá, J.M. 40Ar/39Ar Dating of Gold Mineralization in Brasiliano Strike-slip Shear Zones in the Borborema Province, NE Brazil. Journal of South American Earth Sciences,, in press.
Shuster, D. L., Vasconcelos, P.M., Heim, J.A., and Farley K.A. (2005) Weathering geochronology by (U-Th)/He dating of goethite. Geochimica Cosmochimica Acta, 69, 659-673.
Guedes, E., Heilbron, M., Vasconcelos, P.M., Valeriano, C.; Almeida, J.C.; Teixeira, W., Thomaz Filho, A. (2005) K-Ar and 40Ar/39Ar ages of dikes emplaced in the onshore basement of the Santos Basin, Resende area, SE Brazil: implications for the south Atlantic opening and Tertiary reactivation, Journal of South American Earth Sciences, 18(3-4): 371-382.

2004
Carmo I. O. and Vasconcelos P. (2004) Geochronological evidence for pervasive Miocene weathering, Minas Gerais, Brazil. Earth Surface Processes and Landforms, 29(11): 1303-1320.

2003
Li, J. W., Vasconcelos P. M., and Zhang J., Zhou M, Zhang X. (2003) Timing and duration of gold mineralization under continental transtension regime: 40Ar/39Ar constraints on the Jiaodong gold province, east China. J. of Geology, 111, 741-751.
Araújo, M. N. C., Silva, F. C. A., Sa, E. F. J., Holcombe, R. J., and Vasconcelos, P.M. (2003) Microstructural evolution of the Serido Belt, NE-Brazil: the effect of two tectonic events on development of c-axis preferred orientation in quartz. Journal of Structural Geology, 25 (12), 2089-2107.
Vasconcelos, P. and Conroy, M. (2003) Geochronology of weathering and landscape evolution, Dugald River, NW Queensland, Australia. Geochimica et Cosmochimica Acta, 67 (13), 1-42.

2002
Li, J. W., Vasconcelos, P. M., and Zhang, J. (2002) Behaviour of argon gas release from manganese oxide minerals as revealed by Ar-40/Ar-39 laser incremental heating analysis. Chinese Science Bulletin, 47(18), 1502-1510.
Li, J.W. and Vasconcelos, P. (2002) Cenozoic continental weathering and its implications for paleoclimatic: evidence from 40Ar/39Ar geochronology of supergene K-Mn oxides in Mt. Tabor, central Queensland, Australia. Earth and Planetary Science Letters, 200: 223-239.
Rizotto, G.J., Bettencourt, J.S., Teixeira, Pacca, I.I.G., D'Agrella Filho, M.S., Vasconcelos, P., Basei, A.S., Onoe, A.T., and Passarelli, C.R. (2002) Geologia e Geocronologia da suite metamorfica Colorado e suas encaixantes, SE de Rondonia: implicacoes para a evolucao mesoproterozoica do SW do Craton Amazônico. Revista do Instituto de Geociências - USP, 2:41-55.
Vasconcelos, P.M., Onoe, A.T., Kawashita, K., Soares, A.J. and Teixeira, W. (2002) 40Ar/39Ar geochronology at the Instituto de Geociências, USP: instrumentation, analytical procedures, and calibration. An. Acad. Bras. Ciênc., 74(2): 297-342.

2001
Feng, Y.X. and Vasconcelos, P.M. (2001) Quaternary Continental Weathering Geochronology by Laser-Heating 40Ar/39Ar Analysis of Supergene Cryptomelane. Geology, 29(7):635-638.

2000
Cranfield, L., Horton, D., and Vasconcelos, P. (2000) New Western Queensland opal field maps. Queensland Government Mining Journal, May, 42-45.

1999
Vasconcelos P.M. (1999) K-Ar and 40Ar/39Ar Geochronology of Weathering Processes. Annu. Rev. Earth Planet. Sci. 27:183-229.
Vasconcelos P.M. (1999) 40Ar/39Ar Geochronology of Supergene Processes in Ore Deposits. Reviews in Economic Geology. 12, 73-113.

1998
Vasconcelos, P.M. (1998) Geochronology of weathering in the Mt Isa and Charters Towers regions, northern Queensland. Restricted Report 68R/E&M Rep. 452R, Perth, Australia, CRC LEME.