Nova Terra 52

Chapter 4. Contrasting isotopic sources (Sm-Nd) of Late Ediacaran series in the Iberian Massif: Implications for the Central Iberian-Ossa Morena boundary ...............................................23 Chapter 5. Geochemistry and Sm–Nd isotopic sources of Late Ediacaran siliciclastic series in the Ossa–Morena Complex: Iberian–Bohemian correlations .........................................................41 Chapter 6. Tectonostratigraphy of the Mérida Massif reveals a new Cadomian suture zone exposure in Gondwana (SW Iberia) ....................................................................................65 Chapter 7. U-Pb geochronology and isotopic geochemistry of adakites and related magmas in the Ediacaran arc section of the SW Iberian Massif: The role of subduction erosion cycles in peri-Gondwanan arcs ..............................................................89 Chapter 8. Opening and closure of Cadomian peri-Gondwanan oceans: age and evolution of the Mérida Ophiolite (SW Iberia) ...................................117 Chapter 9. Malcocinado Formation. Ending of the Cadomian arc cycle in the SW Iberian Massif ..................................................153 9.1 Introduction..........................................................................................................155 9.2 Geological setting.................................................................................................156 9.2.1 Reference section of the Malcocinado Formation..........................................157 9.3 Sample selection and methodology......................................................................159 9.3.1 Sample selection.............................................................................................159 9.3.2 whole-rock major and trace element...............................................................159 9.3.3 Whole-rock Sr-Nd isotopic analysis...............................................................159 9.4 Results..................................................................................................................159 9.4.1 Petrographic features......................................................................................159 9.4.2 Whole rock geochemistry................................................................................161 9.4.3 Sr-Nd isotopic geochemistry...........................................................................163 9.5 Discussion............................................................................................................164 9.5.1 Geochemistry and isotopic sources during Ediacaran-Cambrian transition.........................................................................165 9.5.2 Tectonic setting: An incipient geodynamic switching....................................167