The Acadian fold belt in the Meguma Terrane, Nova Scotia: Cross sections, fold mechanisms, and tecto

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The Acadian fold belt in the Meguma Terrane, Nova
Scotia Cross sections, fold mechanisms, and
tectonic implications

• Nicholas Culshaw and Sharon K. Y. Lee
• Department of Earth Sciences, Dalhousie
  University, Halifax, Nova Scotia, Canada
• TECTONICS, VOL. 25 published 20 May 2006

Margaret Parks, UCLA, 4 December 2006
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Regional Setting and History
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Region of Interest
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Questions

• What is the relationship of the Meguma Group to
  the Appalachian orogen?
• External foreland fold and thrust belt?
• Relationship to basement?
• Relationship to crustal tectonics?
• Why was the SMB emplaced?

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Methods

• Maps and cross sections derived from GIS-based
  compilation of digital geophysical (magnetic
  grid) and geological vector data
• Cross sections constructed using the kink method

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Regional Structural Geology
Histogram of map width of anticline and
Histogram of bedding dip for each structural
domain
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Cross Sections
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Undeformed Sections along B-B
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Crustal-Scale cross section showing structural
development of the Acadian fold belt
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Conclusions

• No thrust faulting- ductile shear zone instead
• Depth to detachment 11-13.5 km
• Folds are due to buckling from gravity
• Granite bodies emplaced by delamination
• Slight further deformation due to movement on the
  CCFS and erosion