Using Structural Analysis to Assess Possible Formation Mechanisms of the Gneiss Domes of the Harvey Cardiff Domain, Eastern Ontario

• Main Author: Sendek, Callie
• Format: Others
• Published: Scholarship @ Claremont 2012
• Subjects: gneiss domes; Grenville Orogeny; Harvey Cardiff Domain; Central Metasedimentary Belt; Tectonics and Structure
• Online Access: http://scholarship.claremont.edu/scripps_theses/84; http://scholarship.claremont.edu/cgi/viewcontent.cgi?article=1088&context=scripps_theses

Gneiss domes are structural features associated with orogens worldwide. This study provides a structural analysis of the domes of the Harvey Cardiff Domain, associated with the Grenville Orogeny. Structural data and oriented samples were collected during field work in the summer of 2012. These were used in combination with published and unpublished foliation and lineation data to analyze structural patterns and determine a mechanism of formation for the domes. The end member scenarios for dome formation were taken from the gneiss dome classification scheme devised by Yin (2004). Most of these mechanisms were eliminated based on a lack of necessary large scale geologic features in the region of the study area. An analysis of the foliation pattern of the Cheddar and Cardiff domes was most consistent with formation by diapirism. However, the foliation patterns of the domes differ from the expected diapiric pattern, and seems to represent a non-horizontal slice through a diapir, cutting through a diapir neck in the north and a diapir hat in the south. This pattern can also be explained by rotation of diapiric foliation due to strain induced by the main orogenic event. This hypothesis was tested using COMSOL, a finite elastic strain model, and found to be realistic. With the methods used in this study it is not possible to tell whether this rotation occurred after or during dome emplacement.