Precambrian Research, 45 (1989) 353-354 353 Elsevier Science Publishers B.V., Amsterdam - - Printed in The Netherlands

CONTENTS

Volume 45, Nos. 1-3, 1989 Special Issue: Proterozoic Geochemistry

Contents, special issue .................................................................................................................................................................... vii Editorial Preface .............................................................................................................................................................................. ix Research Papers Geochemistry of the Trans-Labrador granitoid belt, Canada. A qualitative comparative study of a Proterozoic

batholith and possible Phanerozoic counterparts A Kerr (Newfoundland, Canada) ........................................................................................................................................... 1

Early Proterozoic crust-mantle interaction at a continental margin in northern Sweden T. SkiSld (Stockholm, Sweden) and B. (3hlander (Lule~, Sweden) ................................................................................... 19

U-Pb zircon ages and Rb-Sr whole-rock isotope studies of early Proterozoic volcanic and plutonic rocks near Tampere, southern Finland Y. KiihkSnen (Helsinki, Finland), H. Huhma (Espoo, Finland) and K. Aro (Helsinki, Finland) ................................. 27

Age, tectonic setting and provenance of Ostfold-Marstrand Belt Supracrustals: westward crustal growth of the Baltic Shield at 1760 Ma K.I./~h~ill (GSteborg, Sweden) and J.S. Daly (Dublin, Ireland) ......................................................................................... 45

Pechenga ferropicrites and other early Proterozoic picrites in the eastern part of the Baltic Shield E.J. Hanski (Rovaniemi, Finland) and V.F. Smolkin (Apati~, U.S.S.R.) ....................................................................... 63

Hybridisation in middle Proterozoic high-level ring complexes, Aland, SW Finland N.P. Branigan (Dundee, Gt. Britain) ..................................................................................................................................... 83

Formation of granitic magmas during repeated orogenic events; an example from the Baltic Shield A. Lindh and K. Holme (Lund, Sweden) ............................................................................................................................... 97

Monzonorites from Rogaland (Southwest Norway): a series of rocks coeval but not comagmatic with massif-type anorthosites J.C. Duchesne and E. Wilmart (Sart Tilman, Belgium), D. Demaiffe (Bruxelles, Belgium) and J. Hertogen (Leuven, Belgium) ................................................................................................................................................................... 111

Two geochemically different types of precambrian crust in the Anabar Shield, North Siberia O.M. Rosen (Moscow U.S.S.R.) ............................................................................................................................................. 129

Elemental mobilities produced by low-grade metamorphic events. A case study from the Proterozoic supracrustals of southern Norway T.S. Brewer and B.P. Atkin (Nottingham, Gt. Britain) ...................................................................................................... 143

Isotope and geochemical constraints on Proterozoic crustal evolution in south-easteru Africa B.M. Eglington and R.E. Harmer (Pretoria, South Africa) and A. Kerr (Durban, South Africa) .................................. 159

Isotopic evolution of the Middle to Late Proterozoic Awasib Mountain Terrain in southern Namibia B.G. Hoal (Windhoek, Namibia), R.E. Harmer and B.M. Eglington (Pretoria, South Africa) ...................................... 175

Tectonic setting discrimination in clastic sequences: an example from the Late Proterozoic Erris Group, NW Ireland J.A. Winchester (Keele, Gt. Britain) and M.D. Max (Washington D.C., U.S.A.) ............................................................ 191

Geochemistry and tectonic setting of Lewisian clastic metasediments from the Early Proterozoic Loch Maree Group of Gairloch, NW Scotland P.A. Floyd, J.A. Winchester and R.G. Park (Keele, Gt. Britain) ........................................................................................ '203

Contrasting geochemistry of two pegnmtite fields in Manitoba: products of juvenile Aphebian crust and polycyclic Archean evolution P. Cern~ (Manitoba, Canada) ................................................................................................................................................. 215

The granitoids of the Moravian Zone of northeast Austria: Products of a Cadomian active continental margin? F. Finger, G. Frasl, V. H~ick and H.P. Steyrer (Salzburg, Austria) ..................................................................................... 235

Geochemistry and geotectonic interpretation of the Penthievre crystalline massif, northern Brittany, France M.M. Shufflebotham (Aberystwyth, Gt. Britain) ................................................................................................................. 247

354

Volume 45 No.4

Research Papers Crustal domains in the northern Kaapvaal craton as defined by magnetic lineaments

E.H. Stettler, J.H. de Beer and M.P. Biota (Pretoria, South Africa) ............................................................................................. 263 Metamorphism and geochronology of gtanulites and migmatitic granulites from the Magondi Mobile Belt, Zimbabwe

P.J. Treloar (London, Gt. Britain) and J.D. Kramers (Harare, Zimbabwe) ................................................................................ 277 Interstitial and peloid microfossils from the 2.0 Ga Gunflint Formation: implications for the paleoecology of the Gunflint

Stromatolites W.P. Lanier (Emporia, KS, U.S.A.} .................................................................................................................................................. 291

Tectonic evolution of the Sergipano Fold Belt, NE Brazil, during the Brasiliano orogeny I. Davison {Surrey, Gt. Britain) and R.A. Santos (Bahia, Brazil) ................................................................................................. 319

Short Note L'eclogite de Farateiho (Madagascar): un cas exceptionnel de m~tamorphisme de haute-P-basse-T au Prot~rozo'ique

sup~rieur C. Nicollet (Clermont-Ferrand, France) ........................................................................................................................................... 343

Erratum ....................................................................................................................................................................................................... 355