Hostname: page-component-848d4c4894-5nwft Total loading time: 0 Render date: 2024-06-08T20:18:13.048Z Has data issue: false hasContentIssue false
  • English
  • Français

REE distribution in presentday and ancient surface environments of basaltic rocks (Central Portugal)

Published online by Cambridge University Press:  09 July 2018

M. I. Prudêncio ,
M. A. Gouveia  and
M. A. Sequeira Braga
M. I. Prudêncio
Affiliation:
Departamento de Quírnica, ITN, Estrada Nacional 10, 2685 Sacavém, Portugal
M. A. Gouveia
Affiliation:
Departamento de Quírnica, ITN, Estrada Nacional 10, 2685 Sacavém, Portugal
M. A. Sequeira Braga
Affiliation:
Universidade do Minho, Ciências da Terra, 4719 Braga codex, Portugal
Get access Rights & Permissions [Opens in a new window]

Abstract

Rare earth elements are mobilized, fractionated and precipitated during weathering processes of basaltic rocks of the Lisbon Volcanic Complex. In general there is an increase in the REE contents in the whole samples with increasing weathering and fractionation between LREE and HREE. Cerium is partially oxidized and Ce4+ is retained resulting in negative Ce anomalies in the whole samples of the base and middle profile zones. In the clay fraction there is an increase in the REE contents from the top to the bottom of the profiles, except for Ce, giving rise to positive Ce anomalies in the top and negative anomalies of this element in the middle and bottom of the profiles. Significant positive Ce anomalies occur in the finer fractions of palaeoweathered (Upper Cretaceous/ Lower Eocene) basalts associated with low REE contents relative to the whole samples indicating more intense leaching conditions in the Upper Cretaceous/Lower Eocene than at the present day. However, in both cases no positive Ce anomalies were found in the whole samples. There appears to be a negative correlation between the (La/Yb)ch ratio variation and the clay mineralogy/drainage conditions.

Type
Research Article
Information
Clay Minerals , Volume 30 , Issue 3 , September 1995 , pp. 239 - 248
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1995

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Banfield, L.F. & Eggleton, R. (1989) Apatite replacement and rare earth mobilization, fractionation and fixation during weathering. Clays Clay Miner. 37, 113–127.CrossRefGoogle Scholar
Buskovskiy, V.Z., Mineyev, D.A. & Kholodov, V.N. (1969) Accessory lanthanides in phosphorites. Geokhimiya, 11, 1348–1361.Google Scholar
Bonnot-Courtois, C. (1981) Géochimie des terres rares dans les principaux milieux de .formation et sédimentation des argiles. PhD thesis, Univ. de Paris-Sud, 217pp.Google Scholar
Bonnot-Courtois, C. & Flicoteaux, R. (1989) Distribution of rare-earth and some trace elements in Tertiary phosphorites from the Senegal Basin and their weathering products. Chem. Geol. 75, 311–328.CrossRefGoogle Scholar
Braun, J., Pagel, M., Muller, J., Bilong, P., Michard, A. & Guillet, B. (1990) Cerium anomalies in lateric profiles. Geochim. Cosmochim. Acta, 54, 781—795.CrossRefGoogle Scholar
Burkov, V.V. & Podporina, E.K. (1970) Some geo-chemical characteristics of rare (trace) elements in weathering crusts. Translated from Litoligiya i Poleznye lskopaemye, 4, 55—64.Google Scholar
Decarreau, A., Courtois, C. & Steinberg, M. (1979) Comportement des é1éments de la première série de transition et des lanthanides dans les altérations naturelles et expérimentales. Sci. Géol. 53, 29—34.Google Scholar
Duddy, I.R. (1980) Redistribution and fractionation of rare-earth and other elements in a weathering profile. Chem. Geol. 30, 363–381.CrossRefGoogle Scholar
Elliot, W.C. (1993) Origin of the Mg-smectite at the Cretaceous/Tertiary (K/T) boundary at Stevens Klint, Denmark. Clays Clay Miner. 41, 442–452.CrossRefGoogle Scholar
Fortin, P. (1989) Mobilisation, fractionnement et accumulation des terres rares lots de l’altération latéritique de sédiments argilo-sableux du Bassin de Curitiba (Brésil). PhD thése, Ecole des Mines de Paris, Mémories des Sciences de la Terre 10, 186.Google Scholar
Furon, R. (1950) Les problèmes de paléoclimatologie et de paléobiologie posés par la géologie de l'Arctide. C.R. strum. Séances Soc. Biogéogr. 230, 13—23.Google Scholar
Gouveia, M.A., Prudâncio, M.I., Morgado, I. & Cabral, J.M.P. (1992) New data on the GSJ reference rocks JB-la and JG-la by instrumental neutron activation analysis. J. Rad. Nuc. Chem. 158, 115–120.CrossRefGoogle Scholar
Haskin, L.A., Helmke, P.A., Paster, T.P. & Allen, R.O. (1971) Activation Analysis in Geochemistry and Cosmochemistry (Brunfelt, A.O. & Steinnes, E., editors), Universitetsforlaget, Oslo, pp.201–218.Google Scholar
Kholooov, V.N. (1972) Behaviour of the rare earths during weathering of the Karatau phosphorites. Geokhimiya 9, 1063–1070.Google Scholar
Kronberg, B.I., Tazaki, K. & Melh, A.J. (1987) Detailed geochemical studies of the initial stages of weathering of alkaline rocks: Ilha de S. Sebastião, Brazil. Chem. Geol. 60, 79–88.CrossRefGoogle Scholar
Malengreau, N. (1990) Comportement des terres rares et évolutions des compositions isotopiques du Sr et du Nd dans un perfil d’altération développé sur roches basiques. Repport du DEA Géosciences l'Énvironment, Université d'Aix-Marseille Ill.Google Scholar
Marsh, J.S. (1991) REE fractionation and Ce anomalies in weathered Karoo dolerite. Chem. Geol. 90, 184–194.Google Scholar
Melfi, A.J., Figueiredo, A.M., Kronberg, B.I., Dohert, W.D. & Marques, L.S. (1990) REEmobilities during incipient weathering of volcanic rocks of the Paraná basin, Brazil. Chem. GeoL 84, 375–376.CrossRefGoogle Scholar
Nesbitr, H.W. (1979) Mobility and fractionation of rare earth elements during weathering of a granodiorite. Nature 279, 206–210.CrossRefGoogle Scholar
Parrish, B. (1982) Causes and consequences of the relation between area and age of the ocean floor. J. Geophys. Res. 87, 289–302.Google Scholar
Prudâncio, M.I. (1993) Geoquímica de superfície em rochas basálticas continentais (Portugal). Compor-tamento das terras raras.Tese de doutoramento, Univ. Minho, Portugal.Google Scholar
Prudgncio, M.I., Gouveta, M.A. & Cabral, J.M.P. (1986) Instrumental neutron activation analysis of two French geochemical reference samples — basalt BR and biotite Mica-Fe. Geostand. Newsl. X, 29–31.CrossRefGoogle Scholar
Prudiâncio, M.I., Sequeira Braga, M.A.S. & Cabral, J.M.P. (1990) Geoquímica de superfície das tetras raras em rochas basàlticas do Complexo Vulcânico de Lisboa. VIII Semana de Geoqu[mica, Lisboa, Portugal. Google Scholar
Prudtâncio, M.I., Sequeira Braga, M.A.S. & Gouveia, M.A. (1993) REEmobilization, fractionation and precipitation during weathering of basalts. Chem. Geol. 107, 251–254.CrossRefGoogle Scholar
Prudiâncio, M.I., Gouveia, M.A., Sequeira Braga, M.A.S. & Figueiredo, M.O. (1994). REEdistribution as an indicator of the origin of carbonates and silicates in basaltic rocks. VM Goldschimdt Con-ference, Edinburgh, 1994, Mineral. Mag. 58A, 744–745.Google Scholar
Schieber, J. (1988) Redistribution of rare earth elements during diagenesis of carbonate rocks from the mid-Protrozoic Newland Formation. Chem. Geol. 69, 111–126.CrossRefGoogle Scholar
Schmitz, B., Anderson, P. & Dahl, J. (1988) Iridium, sulfur isotopes and rare earth elements in the Cretaceous/Tertiary boundary clay at Stevens Klint, Denmark. Geochim. Cosmochim. Acta 52, 229—236.CrossRefGoogle Scholar
Steinberg, M. & Courtois, C. (1976) Le comportement des terres rares au cours de l’altération et ses consOquences. Bull. Soc. Géol. France 1, 13—20.Google Scholar
Serralheiro, A. (1978) Contribuição para a actualiza-ção do conhecimento do complexo vulcânico de Lisboa. Univ. Lisboa, Portugal.Google Scholar
Tardy, Y. (1986) Le cycle de l'eau. Climats, paléo-climats et géochimie global. Masson, 338 pp.Google Scholar
Topp, S.E., Salbu, B., Roaldset, E. & Jørgensen, P. (1985) Vertical distribution of trace elements in laterite soil (Suriname). Chem. Geol. 47, 159–174.CrossRefGoogle Scholar