The Brodie Mountain ridge is located in the towns of northern hardwood species; its geology is Ordovician phyllite.
22.
The fault separated graphitic phyllite in the east from metasiltstone, argillite, quartz sandstone conglomerate on the west.
23.
The two units meet as a saddle between the twin peaks of meta-argillite / phyllite and granite.
24.
Most of the bedrock underlying the township is Cambrian-era slate, schist, phyllite, greywacke and quartzite.
25.
The park's underlying geology consists of Precambrian shale phyllite, quartz, quartzite, schist, and granite.
26.
The quarry wall has an inclined fault where Brisbane tuff meets phyllite, which is significant as a geological rarity.
27.
The phyllite at the granite contact formed a weak horizon, which assisted the decollement process after the batholith was emplaced.
28.
The bedrock is the Lower Cambrian Sugarloaf Mountain Quartzite, a massive white quartzite interbedded with softer sericitic quartzite, slate, and phyllite.
29.
Mount Yonaha is formed from schist, phyllite, and sandstone, and dates from the Tertiary period to the mid-Mesozoic era.
30.
The protolith ( or parent rock ) for phyllite is shale or pelite, or slate, which in turn came from a shale protolith.
