Palaeozoic and mesozoic palaeomagnetism of South America [Elektronische Ressource] : results from Peru, Bolivia, Argentina, and Brazil / vorgelegt von Nicolas A. Rakotosolofo

Rakotosolofo Nicolas

Sujets

• Physik

Informations

• Publié par: ludwig-maximilians-universitat_munchen
• Publié le: 01 janvier 2004
• Nombre de lectures: 14
• Langue: English
• Poids de l'ouvrage: 21 Mo

Extrait

Palaeozoic and Mesozoic Palaeomagnetism of
South America: Results from Peru, Bolivia,
Argentina, and Brazil.









Inaugural–Dissertation
zur Erlangung des Doktorgrades
an der Fakultät für Geowissenschaften der
Ludwig-Maximilians-Universität München










Vorgelegt von
Nicolas A. Rakotosolofo
Mai 2004



1. Berichterstatter: PD Dr. Jennifer Tait
2. Berichterstatter: Prof. Dr. Valerian Bachtadse




Tag der mündlichen Prüfung: 1. Juli 2004



















Acknowledgement

I thank Dr. Jennifer Tait for supervising this thesis and for her
advise and supports. Thank you to my co-advisor Dr. Valerian
Bachtadse for his enthusiastic help.
I also thank Dr. Christoph Heunemann and Dr. Kari Anderson
for the constructive comments on the early version of this thesis.
I thank Prof. Peter Isaacson and Dr. George Grader (University
of Idaho, USA), Dr. Victor Carlotto and Dr. Jose Cárdenas
(Universidad Nacional San Antonio Abad del Cusco, Peru), Dr.
Udo Zimmermann (Universidad Nacional de Catamarca,
Argentina), Dr. Virgínio Neumann (Universidade Federal de
Pernambuco, Brazil), Mr. Oscar Peréz (Bolivia) and all who help
me throughout my field works for their valuable suggestions and
their generous assistance.
Thank you to all members of the “sektion geophysik” (LMU) for
their support and friendship.
Funding of this project provided by the Volkswagen-Stiftung is
gratefully acknowledged.
Table of contents

List of Figures.................................................................................................................4
List of Tables ..................................................................................................................7
Glossary ........................................................................................................................ 8
Abstract.. 9
Zusammenfassung ........................................................................................................ 13

Chapter 1 Introduction
1.1 Gondwana and Pangaea Supercontinents.................................................... 17
1.2 Palaeomagnetic data from Gondwana......................................................... 18
1.3 Palaeomagnetic data from South America.................................................. 21

Chapter 2 Geological setting of the sampling regions
2.1 The Parnaíba Basin ...................................................................................... 23
2.2hwestern margin of South America ....................................................... 25
2.3 The Central Andes ....................................................................................... 26
2.3.1 Pre-Andean evolution of the Central Andes ............................................... 27
2.3.2 The Peruvian Andes..................................................................................... 29
2.3.3hBolivian Andes30
2.3.4 The Andes of northwestern Argentina ........................................................ 31

Chapter 3 Palaeomagnetic sampling and techniques
3.1 Sampling regions.........................................................................................35
3.2 Sampling methods........................................................................................ 36
3.3 Palaeomagnetic measurement.....................................................................37

Chapter 4 A new Cretaceous palaeomagnetic pole from NE Brazil
4.1 Introduction.................................................................................................. 41
4.2 Sardinha Formation (Early Cretaceous)...................................................... 43
4.2.1 Sampling details........................................................................................... 43
4.2.2 Rock magnetic properties ............................................................................ 45
4.2.3 Palaeomagnetic results................................................................................. 45
4.3 Santana Group (Early Cretaceous).............................................................. 51
4.3.1 Sampling details 51
4.3.2 Palaeomagnetic results and interpretations ................................................. 53
4.4 Gramame Formation (Late Cretaceous)...................................................... 54
4.5 Conclusion...................................................................................................56
1 Chapter 5 Remagnetisation of the Palaeozoic rock units within the Parnaíba
Basin, NE Brazil
5.1 Sampling details........................................................................................... 57
5.2 Palaeomagnetic results and interpretation................................................... 59
5.2.1 Pedra de Fogo Formation (Early Permian) ................................................. 59
5.2.2 Piauí Formation (Late Carboniferous) ........................................................ 62
5.2.3 Pimenteiras Formation. (Early Devonian) 64
5.2.4 Itaim Formation (Early Devonian).............................................................. 68
5.2.5 Tianguá Formation (Early Silurian) ............................................................ 71
5.3 Summary and conclusion............................................................................. 74

Chapter 6 Permian-Triassic palaeomagnetic data from southern Peru:
implication for Pangaea palaeogeography
6.1 Introduction.................................................................................................. 76
6.2 Mitu Group (Early Triassic; Altiplano)....................................................... 77
6.2.1 Sampling......................................................................................................77
6.2.2 Results..........................................................................................................79
6.2.3 Interpretation................................................................................................ 84
6.3 Copacabana Group (Early Permian; Subandean Zone) .............................. 86
6.3.1 Sampling86
6.3.2 Palaeomagnetic results and interpretations ................................................. 87
6.3.3 Rock magnetic properties ............................................................................ 93
6.4 Discussion....................................................................................................96
6.5 Conclusion.................................................................................................102

Chapter 7 Early Ordovician palaeomagnetic data from the Altiplano, Southern
Peru
7. 1 Sampling 104
7.2 Palaeomagnetic results and interpretation................................................. 104
7.3 Discussion and conclusion......................................................................... 106

Chapter 8 Palaeomagnetic results from Ordovician to Carboniferous sediments
of the Subandean Zone and the Eastern Cordillera
8.1 Introduction................................................................................................ 109
8.1.1 Taiguati Formation (Early Carboniferous)................................................ 111
8.1.2 Iquiri-Los Monos Formation ( Early Carboniferous; Bolivia) ................. 111
8.1.3 Huamampampa Formation (Middle Devonian; Bolivia).......................... 118
8.1.4 Other Palaeozoic rock units....................................................................... 120
8.2 Conclusion.................................................................................................122


2 Chapter 9 Palaeomagnetism of the Permian-Carboniferous rocks of the
PampeanRanges and the Paganzo Basin, NW Argentina
9.1 Introduction................................................................................................ 124
9.2 Pampean Ranges........................................................................................125
9.2.1 La Antigua Formation (Early Permian) .................................................... 125
9.3 Paganzo Basin............................................................................................129
9.3.1 Malanzán Formation (Namurian-Westphalian) ........................................ 129
9.3.2 Solca Formation (Stephanian) ................................................................... 132
9.4 Summary and conclusion........................................................................... 134

Chapter 10 Palaeomagnetic results from the Argentine Precordillera and the
Famatina Ranges, NW Argentina
10.1 Introduction................................................................................................ 137
10.2 Palaeomagnetism of the Argentine Precordillera ..................................... 140
10.2.1 Patquia Formation (Late Permian) ............................................................ 140
10.2.2 Guandacol Form