Rare earth and other trace element mobility accompanying albitization in a Proterozoic granite, W. Bergslagen, Sweden

Abstract

AbstractZones of albitization 20 m wide are developed in the peraluminous, undeformed Proterozoic Bastfallshöjden granite, W. Bergslagen, central Sweden. During albitization Na, Si, Mg, Ni, Zn, and Ga are added, while Fe2+, Fe3+, Mn, K, Sc, Rb, Cs, Ba, Pb, U, and F are lost, together with the rare earth elements (REE) in decreasing amounts with increasing atomic number. Ti, Al, P, and Y were immobile. Trace element data for chlorites separated from hydrothermally altered country rocks and from a quartz-chlorite vein in the albitized granite show similar REE patterns indicating a common origin: the most altered granite has a similar REE pattern, probably resulting from interaction with the same hydrothermal fluid which produced the chlorites, in which seawater is thought to have been an important constituent.