Douglas Stewart Turnbull HBSc thesis abstract

Ductility contrasts between individual clasts and matrix and the affects of a single, non-coaxial, pure shear deformation has resulted in the heterogeneous and non-passive strain features observed on a two dimensional outcrop surface of the Seine Conglomerate in northwestern Ontario.

Two strain analysis techniques yielded different stain values for each clast lithology thus reflecting the relative competencies.

The bulk strain of the conglomerate outcrop is partitioned between the ductile matrix and a rigid framework of the more competent clasts.  The finite strain ratios of metavolcanic clast may represent the state of strain of the matrix due to the passive manner in which the two components have deformed.  The bulk strain of 72.5% shortening is intermediate between the value calculated for the metavolcanic clasts and the granitoid clasts.

Values of strain calculated for the porphyritic igneous clasts are close to the estimated bulk strain ratio for the entire outcrop.  Thus the popphyritic clasts are a small scale analogy of the conglomerate: porphyritic clasts have a rigid phenocryst versus ductile groundmass phase similarily, the conglomerate has a rigid clast versus a ductile matrix phase.