Pre-Mesozoic Geology in the Alps

662 Pages·1993·50.84 MB·English

by  O. Adrian Pfiffner (auth.)

1. F. von Raumer F. Neubauer (Eds.)
Pre-Mesozoic
Geology
in the Alps
With 279 Figures and 32 Tables
Springer-Verlag
Berlin Heidelberg New York London Paris Tokyo
Hong Kong Barcelona Budapest
Prof. Dr. J. F. von RAUMER
Institut fOr Mineralogie und Petrographie
Universitat Perolles
CH- 1700 Fribourg
Switzerland
Prof. Dr. FRANZ NEUBAUER
Institut fur Geologie und Palaontologie
Karl-Franzens-Universitat
HeinrichstraBe 26
A-8010Graz
Austria
ISBN-13 :978-3-642-84642-7 e-ISBN-13 :978-3-642-84640-3
DOl: 10.1007/978-3-642-84640-3
Library of Congress Cataloging-in-Publication Data
Pre-Mesozoic geology in the Alps / l. Evon Raumer, E Neubauer (eds.). p. em. Includes bibliographical references
and index.
ISBN-13:978-3-642-84642-7 1. Geology, Stratigraphic-
Paleozoic. 2. Geology-Alps. I. Raumer, l. Evon (liirgen E), 1932- . II. Neubauer, Franz, 1951- . QE654.P745
1993' 551.7'2'094947-dc20
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Preface
The Alps are an arched mountain chain stretching 1500 km between Vienna and Graz
in Austria and Genova in Italy. They resulted from the collision of the African and
Laurasian plates during Mesozoic and Tertiary times. The high standard of knowledge
attained over the last 30 years by the working groups on "Alpine Metamorphism" is
well known and helped considerably to recognize pre-Mesozoic elements in the Alps.
In Part I of this book the subdivision of the major Alpine units and pre-Mesozoic pal
inspastic reconstructions are covered before discussion of the pre-Mesozoic geology
in Parts II, III and IV It is understood that the Mesozoic and later events overprinted
pre-existing structures veiling the earlier history and the nature of protoliths.
Although the Alpine overprint does not facilitate the recognition of older struc
tures, pre-Mesozoic basement units were recognized during the first beginnings of
geological observations in the Alps, about 200 years ago. Fifty percent of the Alpine
domain is underlain by basement units that have been unconformably covered since
Permian and Mesozoic times. This basement appears today in a complex pattern
among the Alpine structures. The history of their discovery and explanation, parallel
with a growing sophistication of research methods, are the subject of the introductory
chapter of Part II.
Stratigraphic work in the Alpine domains has been undertaken since the middle of
the last century by several geological schools. Detailed knowledge of fossil-bearing
Ordovician to Permian sedimentary sequences led to very early evolutionary models
for the timing of Variscan orogeny in the Alps. However, the relationships of wide
spread metamorphic units have been a matter of discussion up to the present. As Al
pine basement appears in most areas as high-grade metamorphic units, it was not in
cluded in the general interpretation of the Variscan framework in Europe. It was the
growing knowledge of Alpine metamorphic events and Alpine palaeogeographic
framework, and the application of lithostratigraphic comparative work in high-grade
metamorphic terrains, that allowed the possibility of comparing pre-Mesozoic struc
tures outside the Alps with those encountered in the Alps. Also, over the last 10 years,
the psychological barriers that impeded correlation among the main Variscan structu
res, including those in the Alps, have been reduced.
Since 1983, three meetings influenced considerably the actual knowledge on base
ment correlations in the Alps: the conference on "Variscan and Prevariscan elements
in the Swiss Alps" (contribution to IGCP No.5) held at Fribourg in 1983, the confer
ence on "Caledonian-Variscan structures of the Alps" (3rd meeting "Geodynamics
in the European Variscides") organized at Fribourg in 1987, and the lectures given
during the advanced short course "Comparision of Variscan and pre-Variscan structu
res inside and outside the Alps", organized at Fribourg, March 1990, and headed by
the "3e cycle Romand en Sciences de la Terre". During this last meeting, the lecturers
with topics concerning the Alps agreed to contribute their papers to this volume. En
couraged by the positive answers, the editors decided to organize this volume.
Different factors contributed to the rather slow evolution of ideas concerning the
basement in the Alps. In the Western Alps, the data collection in the Alpine domain is
hindered by the climatic conditions at higher altitudes, the fieldwork seasons being of-
VI Preface
ten rather short. The advance of glaciers at the end of the last century (the "small gla
ciation") slowed down discoveries considerably. In addition to the climatic difficulties,
there are also those of accessibility. The steep morphology is the expression of the
recent uplift. Although the outcrop conditions are very often excellent, the mapping
takes, in consequence, about four times as long as in areas of the Central European
Variscan mountains. Also, sampling very often means backpacking heavy loads over
many kilometres and a thousand metres change in elevation.
Perhaps the greatest difficulty, however, results from the multiple Alpine over
print. Gathering data in the Alpine domain requires longer experience to enable
recognition of the, sometimes subtle, differences between rock units formed by the
different Alpine overprints. This holds especially true for the Penninic domain where
the general metamorphic overprint accompanied by a multitude of deformations cau
ses most rock units to appear simply to be greenschists! In addition, except for the
well-dated fossiliferous Palaeozoic units, most areas are underlain by polymetamor
phic lithologies. Keeping such difficulties in mind the reader may understand that
even 200 years of data collection may not be sufficient to answer all questions. Never
theless, the very long tradition of geological research in the Alps has led to a wealth of
data found in a vast literature, and presented here in two parts.
Part II, in addition to the introduction to the historical evolution of knowledge of
the basement, presents general palaeontological and geochronological data, compa
rative studies of ultramafic rocks and are deposits, and the Late Variscan evolution
through palaeomagnetic data, the wide evolution of Late Variscan granitoids, and the
Late Variscan-Early Mesozoic plate reorganization. These sections give a sound back
ground for the regional descriptions which follow.
In Part III, presentation of the regional data follows the classic separation into the
Helvetic, Penninic, Austro-Alpine and South-Alpine domains. The basic idea in plan
ning the book was to cover the entire Alpine basement through independent contribu
tions which can also stand alone. In the regional sections, each basement unit is pre
sented by the working team with personal experience in this area. All contributions
reflect specific interests of contributors and only give, therefore, minor importance to
other aspects of geology. All significant data, however, are included in the contribu
tions. As independent working groups share specific topics in their research, we inclu
ded data and interpretations from several groups to cover all recent work. This proce
dure implies some repetitions but yields more complete models. The same is true for
sections treating specific aspects from basically the same area, e. g. the Austro-Alpine
basement.
Finally, in the concluding sections of Part IV only do we try to coordinate all the
data and to deduce a general, pre-Mesozoic evolution of the Alpine domain, which
cannot be separated from the evolution of the Variscan geological framework in Cen
tral Europe.
We wish this book to serve as a source of data and as a guide to the corresponding li
terature. Papers concerning the basement are written in many different languages and
are often published in local journals, sometimes not easily obtained, even by people
working in the Alps. Although we tried to cover all basement areas of the Alps, we feel
that the density of data and discussion vary considerably when comparing the differ
ent papers. It becomes evident that the state of knowledge is not equal in the whole
area. This should initiate future research in very different domains. Sedimentological
records of Permian, Carboniferous and older sediments are needed for documenta
tion of basin dynamics, and more knowledge about regions being eroded. In spite of
the Alpine overprint, it should prove possible to gather much more P-T-data from
different units and crustal levels. Statistics on zircon morphology, geochemical and
geochronological data are still insufficient for many basement units (e. g. the pre
Variscan granites; metabasic rock series of very different ages). New geochemical cri
teria are needed to obtain better insight into the magmatic and sedimentological evo-
Preface VII
lution through time. And, it is necessary that true geological fieldwork has to be done,
to reinterprete well-known structures!
We hope that this book will not only be used by specialists, but that it may serve as
an introduction to one aspect of the complex and fascinating Alpine geology for those
not familiar with the Alps. We are aware that it is not easy to fulfill this last objective.
Only the good will and interest of all participating authors and the patient work of the
reviewers has made such an enterprise possible. Our warmest thanks go, therefore, to
all authors who participated in this venture, and we point out the special merit of those
who, late in the day, were willing to cover subjects that otherwise would not have been
included. During the period of publication we lost a very good friend, Georg Troll
(Munchen, University) who agreed to collaborate as an author at an early stage.
Besides the reviews presented by the authors of this book, we appreciate those of
M.Brown (College Park, Maryland), C.Chopin (Paris), M.Delaloye (Geneva),
I.Dostal (Halifax), A.Escher (Lausanne), W.Franke (Giessen), H.Fritz (Graz),
B. Hansen (Gattingen), R. D. Hatcher (Knoxville, Tennessee), C. Hawkesworth (Mil
ton Keynes), R. Hall (Munich), H. L. Holzer (Graz), A. Krill (Trondheim), B. Lamme
rer (Munich), H.Laubscher (Basel), I.P.Lefort (Rennes), E.Marton (Budapest),
R. Mason (London), P. Matte (Montpellier), B. Messiga (Pavia), R. D. Nance (Athens,
Ohio), O.Oncken (Potsdam), EParis (Rennes), G.Pestal (Vienna), G.B.Piccardo
(Genoa), W. Pitcher (Liverpool), D. Robinson (Bristol), P. Robinson (Amherst, Mas
sachusetts), I. Rodgers (New Haven, Connecticut), W. Schubert (Wurzburg), I. Schu
macher (Kiel), I. W. Skehan (Weston, Massachusetts) E. Stein (Darmstadt), B. Stack
hert (Bochum), D. H. Tarling (Newcastle), E. Wallbrecher (Graz), W. Wildi ( Geneva).
We thank also Massimo Chiaradia (Fribourg) who compiled the subject index and
prepared the figures at the beginning of Parts I-IV. Finally, we would like to express
our special thanks to Springer-Verlag and the Geosciences Editorial for their pleasant
and fruitful cooperation.
Fribourg/Graz, Mai 1993 I.E VON RAUMER
ENEUBAUER
Contents
Part I: Pre-Mesozoic Basement and Alpine Structures
Map with indication ofthe discussed areas and index of contributions. . . . . . . . . . 1
The Structure of the Alps: An Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
O. A. PFIFFNER
Basement -Cover Relationship in the Western Alps. Constraints for
the Pre-Triassic Reconstructions .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
P. C. DE GRACIANSKY
Palinspastic Reconstruction of the Pre-Triassic Basement Units in the Alps:
The Central Alps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
O. A. PFIFFNER
Palinspastic Reconstruction of the Pre-Triassic Basement Units in the Alps:
The Eastern Alps. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
L. RATSCHBACHER, W. FRISCH
Part II: Pre-Mesozoic Basement of the Alps
Index of contributions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
History of Geological Investigations in the Pre-Triassic Basement of the Alps. .. 55
J. F. VON RAUMER, F. NEUBAUER
Stratigraphy, Biogeography and Climatic Relationships
ofthe Alpine Palaeozoic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
H. P. SCHONLAUB
The Pre-Alpine Evolution of the Continental Crust of the Central Alps-
An Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
D.GEBAuER
Ultramafic Rocks in the Pre-Mesozoic Basement of the Central and External
Western Alps ........................................................ 119
H. R. PFEIFER, G. BUNO, R. P. MENOT, P. STILLE
Pre-Alpidic Ore Deposits in the Central, Eastern and Southern Alps. . . . . . . . .. 145
V. KOPPEL, F. NEUBAUER, E. SCHROLL
Palaeomagnetic Data from the Palaeozoic Basement of the Alps. . . . . . . . . . . . .. 163
H. J. MAURITSCH
Late Variscan Magmatic Evolution of the Alpine Basement. . . . . . . . . . . . . . . . .. 171
B. BONIN (Coord.), P. BRANDLEIN, F. Bussy, J. DESMONS, U. EGGENBERGER,
F. FINGER, K. GRAF, CH. MARRO, I. MERCOLLI, R. OBERHANSLI, A. PLOQUIN,
A. VON QUADT,J.F. VON RAUMER, U.SCHALTEGGER,H.P.STEYRER,D. VISONA,
G.VIVIER
X Contents
Late Palaeozoic - Early Mesozoic Plate Reorganization: Evolution and Demise
ofthe Variscan Fold Belt. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 203
P. A. ZIEGLER
Part III: Specific Descriptions of Pre-Alpine Basement
Chapter 1: The Helvetic Realm
Map with indication ofthe discussed areas and index of contributions. . . . . . . . .. 219
The Pre-Alpine Evolution of the External Massifs .......................... 221
1. F. VON RAUMER, R. P. MENoT, 1. ABRECHT, G. BIINO
Geodynamic Significance of Basic and Bimodal Magmatism
in the External Domain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 241
R. P.MENoT, 1. L. PAQUETTE
Chapter 2: Penninic Realm
Map with indication of the discussed areas and index of contributions. . . . . . . . .. 255
Elements of the Palaeozoic History of the Ligurian Alps. . . . . . . . . . . . . . . . . . . .. 257
L. CORTESOGNO, G. D ALLAGIOVANNA, L. GAGGERO, M. VANOSSI
Passing Through the Brian~on Zone (Brian~onnais, France) . . . . . . . . . . . . . . . .. 279
1. DESMONS, D. MERCIER
The Pre-Alpine Basement ofthe Brian~onnais (Wallis, Switzerland) .......... 297
P. THELIN, M. SARTORI, M. BURRI, Y. GOUFFON, R. CHESSEX
The Dora - Maira Massif. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 317
R. SANDRONE, P. CADOPPI, R. SACCHI, P. VIALON
Evolution of Austro-Alpine and Upper Penninic Basement in the Northwestern
Alps from Variscan Convergence to Post-Variscan Extension . . . . . . . . . . . . . . .. 327
G. Y. DAL PIAZ
The Lepontine Area, a Geochronological Summary. . . . . . . . . . . . . . . . . . . . . . .. 345
Y.KoPPEL
Evolution ofthe Penninic Basement ofthe Eastern Alps . . . . . . . . . . . . . . . . . . .. 349
W. FRISCH, G. VAVRA, M. WINKLER
The Habach-Formation and the Zentralgneis - A Key in Understanding
the Palaeozoic Evolution ofthe Tauern Window (Eastern Alps) . . . . . . . . . . . . .. 361
V. HOCK
The Zentralgneise of the Tauern Window (Eastern Alps): Insight into
an Intra-Alpine Variscan Batholith. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 375
F. FINGER, G. FRAsL, B. HAUNSCHMID, H. LETTNER, A. VON QUADT, A. SCHERMAIER,
A.O. SCHINDLMAYR, H. P. STEYRER
Chapter 3: Austro-Alpine Realm
Map with indication ofthe discussed areas and index of contributions. . . . . . . . .. 393
The Classic Fossiliferous Palaeozoic Units of the Eastern and Southern Alps . .. 395
H. P. SCHONLAUB, H. HEINISCH
The Austro-Alpine Quartzphyllites and Related Palaeozoic Formations. . . . . .. 423
F. NEUBAUER. F. P. SASSI
Contents XI
Palaeozoic Volcanism of the Eastern Alps and its Palaeotectonic Significance. .. 441
J. LOESCHKE, H. HEINISCH
The Pre-Alpine Basement of the Lower Austro-Alpine Nappes in the Bernina
Massif (Grisons, Switzerland; Valtellina, Italy). . . . . . . . . . . . . . . . . . . . . . . . . . . .. 457
P. SPILLMANN, H. BucHI
Evolution ofthe Silvretta Nappe .... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 469
M. MAGGETTI, M. FLISCH
Evolution of the btztal-Stubai, Searl-Campo and Ulten Basement Units. . . . . .. 485
G. HOINKES, M. THONI
Austro-Alpine Basement Complex to the South of the Tauern Window. . . . . . .. 495
B. SCHULZ, G. NOLLAU, H. HEINISCH, G. GODIZART
The Austro-Alpine Metamorphic Basement East ofthe Tauern Window. . . . . .. 515
F. NEUBAUER, W. FRISCH
Late-and Post-Variscan Sediments ofthe Eastern and Southern Alps. . . . . . . . .. 537
K.KRAINER
Chapter 4: Southern Alps
Map with indication ofthe discussed areas and index of contributions. . . . . . . . .. 565
Ivrea Zone and Adjacent Southern Alpine Basement. . . . . . . . . . . . . . . . . . . . . .. 567
S.M.SCHMID
Pre-Alpine Structural and Metamorphic Histories in the Orobic Southern Alps,
Italy ................................................................ 585
G. B. SILETTO, M.1. SPALLA, A. TUNESI, J. M. LARDEAux, A. COLOMBO
The South-Alpine Metamorphic Basement in the Eastern Alps. . . . . . . . . . . . . .. 599
F. P. SASSI, R. SPIESS
The Pre-Alpine Basement in the Alpi Apuane (Northern Apennines, Italy) . . .. 609
P. CONTI, A. DI PISA, M. GATTIGLIO, M. MECCHERI
Part IV: Conclusions
Index of contributions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 623
Late Precambrian and Palaeozoic Evolution of the Alpine Basement-
An Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 625
J. F. VON RAUMER, F. NEUBAUER
The Alpine Basement - Linkage Between Variscides and East-Mediterranean
Mountain Belts ....................................................... 641
F. NEUBAUER, J. F. VON RAUMER
Subject Index. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 665
Contributors
ABRECHT,J.
GEOTEST, Birkenstr. IS
CH-30S2 Zollikofen, Switzerland
BIINO,G.
Institut fUr Mineralogie und Petrographie, Balzerstr. 1
CH-3012 Bern, Switzerland
BONIN,B.
Dept. de Petrologie - Volcanologie, Biitiment S04, Universite de Paris Sud
F-9140S Orsay Cedex, France
BRANDLEIN, P.
Institut fUr Geologie und Mineralogie Universitat Erlangen, Schlossgarten 5
D-8520 Erlangen, Germany
BUCHI,H.
Institut fUr Mineralogie und Petrographie, ETH Zentrum
CH-8092 Zurich, Switzerland
BURRI,M.
Institut de Geologie, Universite de Lausanne BFSH2
CH-I015 Lausanne, Switzerland
Bussy, F.
Institut de Mineralogie, UNIL BFSH2
CH-I015 Lausanne, Switzerland
CADOPPI,P.
Dip. di Scienze della Terra, Via Accademia delle Scienze, S
1-10123 Torino, Italy
CHESSEX,R.
Dept. de Mineralogie, Rue des Maraichers 13
CH-1211 Geneve, Switzerland
COLOMBO,A.
Dip. di Scienze della Terra, Sezione Mineralogia, Via Botticelli, 23
1-20133 Milano, Italy
CONTI,P.
Institut fUr Geologie, Bernoullistr. 32
CH-40S6 Basel, Switzerland
CORTESOGNO, L.
Dip. di Scienze della Terra sez. Petrografia, Corso Europa, 30
1-16132 Genova, Italy