J. G. Clark HBSc thesis astract

This thesis examines a small area of the Neohelikian Alkali Coldwell Complex.  The area is located on the west shore of the Coldwell Peninsula.  The Complex is composed of three intrusive events and is emplaced in an Archean metavolcanic belt.

The rocks of the thesis area, wholly contained in the second intrusive event, are divided into two types: biotite nepheline gabbro and alkali feldspar foid syenite.  The syenitic phase intrudes the gabbro and is either layered or massive.  The layered sections of the syenite contain numerous sedimentary-like structures (cross laminations, convoluted laminations, current troughs, flame structures, load pillows and slump structures).

Detailed mapping and petrologic examination lead to the hypothesis of surge-type density currents with minor gravity settling being the mode of formatin of the layers and sedimentary-like structures.