Tommy Clark HBSc thesis abstract

Thesis Title: 
An Investigation of the Hintikka Breccia Occurrence Related to the Greenwater-Shebandowan Assemblage Unconformity

The Hintikka breccia occurrence is hosted within the Shebandowan Greenstone Belt. The Hintikka breccia is classified based on the key characteristics, most likely as a volcanic breccia, which has been further brecciated by a local fault. The breccia occurrence is very close to the boundary between the Shebandowan intermediate volcanics and the Greenwater mafic volcanics, with a local fault interpreted to be related to the Mokomon fault. The northern and southern areas within the Hintikka property show two different composition breccias. The northern breccia shows characteristics of a mafic flow breccia. The southern breccia has an intermediate composition with randomly oriented felsic and jasper clasts present. It is proposed that the north and south breccias are volcanic flow breccias, which have been potentially further brecciated by the faulting event.

The supracrustal rocks of the Shebandowan Greenstone belt have been subdivided into three main assemblages that have differing ages and distinct lithologic associations. The breccia within the Hintikka property could be associated with either the Greenwater or the Shebandowan assemblage. The Shebandowan has large, unsorted massive volcanic breccias, and is associated with faulting from the D2 event, which likely explains the presence of the fault breccia and the intermediate breccia in the southern part of the property. The northern breccia with more mafic composition can also be associated with the massive unsorted breccia, but with more flow breccia characteristics, which were subsequently influenced by a faulting event. The felsic clasts may be related to the felsic intrusions (such as the Tower Mountain stock) associated with the Shebandowan assemblage. The Kashabowie assemblage cannot be entirely ruled out, as the entire extent of the assemblage is unknown, and it is interleaved with the Greenwater assemblage.