Simon C. Pollard HBSc thesis abstract

Thesis Title: 
A Petrogenetic Study of the "Agglomerate Unit", Pamour One Mine, Timmins, Ontario
Simon C.

The "Agglomerate Unit" at the Pamour One Mine in Timmins, Ontario has been the source of some confusion since its discover.  The unit appears to be composed entirely of volcanic fragments, but its mode of deposition has never been adequately identified.  When the unit was first identified, it was designated the "Agglomerate Unit", as it closely resembled an eruptive, agglomeratic unit under macroscopic examination.  Several examinations of the unit over the last three decades have suggested that the unit was probably a sedimentary rock formed from fragmented volcanic materials.  However, the unit is relatively economically unimportant at the Pamour One Mine, and little work was devoted to the resolution of this problem.  The unit is not regionally extensive, only having been identified at the Pamour One Mine and the Hallnor Mine which lies to the west, adjacent to the Pamour One Mine.  At the Pamour One Mine the unit occupies paleotopographic lows in the surface of unconformity above the Keewatin volcanic rocks.  The unit is conformably overlain by a greywacke turbidite sequence.  Mineralogical and textural examinations of the unit suggest that the unit is derived from the Keewatin volcanics.  The lack of welding within the matrix material indicates that this was not a hot deposit.  The unit displays sedimentary bedding, though this is often hard to discern, and this bedding is conformable with the bedding of the greywacke turbidites.  Macroscopic and microscopic examinations of the clasts and matrix materials indicate that the unit is in fact an immature sediment, which has undergone little transport.  The presence of isolated beds of greywacke within the unit indicate that this unit was deposited in a transitional sedimentary environment and that the unit was deposited continuously over time and not in one rapid pulse.  There is no evidence of localized unit thickening or increases in the density of larger clasts to suggest the presence of a central vent for an agglomeratic eruption.  Indeed the unit is relatively homogeneous under large scale observation.  Consideration of this evidence indicates that the unit is not an agglomerate but that it is an immature basal conglomerate belonging to the Timiskaming sediments.  The unit was not formed as part of a submarine fan sequence as were the sedimentary rocks that lie directly above it.  For these reasons, the unit should be elevated to formation status and renamed the basal volcanic conglomerate formation.