Mineralogy and Petrology (1998) 63:223-241
Mineralogy
Rna
Petrology
© Springer-Verlag 1998
Printed in Austria
Sphalerite remobilization during multistage
hydrothermal mineralization events-
examples from siderite-Pb-Zn-Cu-Sb veins,
Rheinisches Schiefergebirge, Germany
T. Wagner and N. J. Cook*
Mineralogisches Institut, Universit~it Wtirzburg, Federal Republic of Germany
With 7 Figures
Received February 9, 1998;
revised version accepted June 25, 1998
Summary
A widespread feature of Variscan siderite-Pb-Zn-Cu vein deposits in the Rheinisches
Schiefergebirge, Germany, is an overprinting brought about by late-Variscan Sb-rich
fluids which exploited the existing vein geometry. In a number of cases, this later event
led to considerable textural modification of the primary sulphide assemblage. Sphalerite
is a major component of the primary mineralization in the Stahlberg (Mtisen), Sch6ne
Freundschaft (Obersdorf) and Silberwiese (Oberlahr) deposits, Siegerland-Wied district
and the Silbersand (Mayen) and Saarsegen (Altenahr) deposits in the Eastern Eifel.
Primary sphalerite (sphalerite I) displays corrosion, replacement by a range of Pb-Sb-
sulphosalts, partial dissolution and, ultimately, remobilization as a result of the
overprinting event. Remobilized sphalerite has recrystallized (Sphalerite II) directly
from the overprinting fluid. A comparable textural evolution is also noted in samples
from the D6rnberg-Aurora (Ramsbeck) mine, although, in this case, several distinct
stages of textural modification and remobilization are recognised, resulting from a yet
more complex sequence of vein emplacement.
Microanalysis of sphalerite representing distinct stages of textural evolution in each
of the deposits reveals extensive removal of Fe by diffusion ahead of the reactive
replacement front. Second generation sphalerite contains only low contents of Fe. The
data are consistent with theoretical predictions and experimental observations of
interdiffusion of Fe and Zn in sphalerite in contact with a low Fe/Zn fluid. Interaction
with the Sb-rich fluids was sufficiently prolonged to permit substantial textural and
compositional modification of the primary sphalerite, particularly in the case of smaller
* Present address: Geological Survey of Norway, Boks 3006 Lade, N-7040 Trondheim,
Norway