Neil Ross Burns
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B. Sc. (Advanced Major) Thesis
(PDF - 2.7 Mb)
The purpose of this study is to recognize and evaluate structural features that may be related to the emplacement of the South Mountain Batholith. The Acadian orogeny produced folds within the Meguma Terrane with a north-east trend. The South Mountain Batholith (SMB) later intruded the terrane, but its emplacement mechanism is not completely understood. The emplacement may have had a diapiric, doming, and/or ballooning effect in some areas, and all are processes that would have deformed the surrounding country rock. In the Bedford Basin area, the Meguma Group shows several features that suggest deformation related to emplacement. An air-photo interpretation reveals a basin-shaped feature around the Bedford Syncline with a center in the area of Magazine Hill, suggestive of cross folding of regional N-E folds by pluton-related transverse folds with N-W hinges. A cross-section along the axial trace of the Bedford Syncline across the basin reveals an increasing dip toward the granite contact. This change in dip could be the result of a vertical heterogeneous simple shear imposed by the intruding pluton. Analysis of the cross-section indicates that the dipping bedding planes reflect an increase in shear strain toward the contact. These structural features show a strong correlation to deformation expected from an active pluton emplacement; however, strain in a horizontal plane, perpendicular to the pluton boundary, is minor relative to roof-lifting suggested by the cross-section.
Keywords: Meguma Group, South Mountain Batholith, emplacement, deformation, shear
strain, extension, granitoid, cross-section
Pages: 54
Supervisor: Nicholas Culshaw