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Table of Contents - Special Paper 335:

Tectonosomes and Olistostromes in the Argille Scagliose of the northern Apennines, Italy


Abstract 1
Introduction 1

Structural setting of the Ligurian units in the Northern Apennines

3
  Major units and structures 6
  Ligurian nappe 7
  Epiligurian successions 7
  Other structural units 7
  Compressional history 8

Controversy regarding the argille scagliose and olistostromes

8

Criteria for field- to map-scale distinction of tectonosomes and olistostromes in the argille scagliose of the Bologna Apennines


10
  Mesoscopic characteristics 11
  Tectonosomes 11
  Olistostromes 12
  Microscopic to mesoscopic characteristics 14
  Mappable characteristics, original stratigraphy, present stratigraphy 14
  Tectonosomes 14
  Olistostromes 16
  Etymology and usage of the terms 16
  Tectonosomes 16
  Olistostromes 19

Stratigraphy and setting of tectonosomes, olistostromes, and related Epiligurian deposits in the Bologna Apennines


19
  Stratigraphy of tectonosomes and Ligurian olistostromes 19
  LC units of tectonosomes 19
  UCE units of tectonosomes 20
  Tectonosomes as a tectono-stratigraphic unit from a single Ligurian sequence 20
  Ligurian olistostromes 20
  Stratigraphy of the Epiligurian deposits 20
  Stratigraphy of the Epiligurian olistostromes 21
  Normal stratigraphic units associated with the olistostromes 21
  Structural setting of the Bologna Apennines 21
  External structural belt 21
  Internal structural belt 21

Tectonosomes

23
  Stratal disruption in UCE units 23
  UCE2 Unit 23
  UCE1 Unit 23
  Mechanisms of mesoscopically ductile deformation 25
  Stratal disruption in LC units 28
  Macroscale to mesoscale observations 29
  Mesoscale observations 29
  Microscale observations: The scaly fabric of the matrix 34
  Interpretation of microscale to mesoscale structures in the LC units 37
  Relationships between the microscale to mesoscale and the mesoscale to macroscale structures in the LC units 42
  Structural interaction among the tectonosome units 43
  Structural evolution of the tectonosomes 43
  LC units 43
  UCE units 45
  Relationships of UCE and LC 45
  Regional meaning of the tectonosome structures 45
  Lozenge shape in tectonosomes: Shear lenses from macroscale to microscale 46

Olistostromes

46
  Epiligurian olistostromes (EO) 49
  Texture 49
  Composition and origin of the clasts 50
  Disposition 51
  Ligurian olistostromes 52
  Texture 52
  Composition 52
  Disposition and setting 52
  Romagna-Umbria olistostromes 53
  Visignano-Bordignano olistostrome 53
  Ca Nova Pagliarizzo and Castello di Fiagnano olistostromes 53
  Olistostromes: General characters 54
  Genesis of the olistostromes 54
  Mixing of different lithotypes: Present-day and ancient models 55
  Depositional mechanism 58
  Interpretation of the studied olistostromes 58

Summary of depositional and deformational history and setting of tectonosomes and olistostromes


61
  Pre-late Eocene (Eoalpine-Mesoalpine tectonics) 61
  Late Eocene-recent (Neoalpine tectonics) 62

Acknowledgments

63
References cited 64