Temagami Greenstone Belt shear throughout the Link Lake Deformation Zone. These dark compressed pyroclastics have been interpreted to be pumice. Some of the subsequence pyroclastic deposits contain fragments of pyrite and quartz, suggesting that discharged sulfide hydrothermal activity took place throughout the volcanic source area. Resedimented felsic, epiclastic and turbiditic sediments compose the Turtle Lake Formation. The base of this formation consists of a heterolithic, volcaniclastic, matrix-supported conglomerate unit that overlies felsic lava flows and pillowed, calc-alkaline basalts of the Link Lake Formation. Many rounded to subangular felsic and mafic volcanic fragments are known to occur in the unit, as well as rare
Ringing rocks that retained the olivine and pyroxene crystals (OPM) is extremely resistant to weathering and is the material which forms the tors. The altered rock (AM) conversely is very weak and readily breaks down to a coarse soil. The inner felsic core is a medium grained quartz monzonite that gradually grades into granite at the center. The transitional unit between the mafic zone and the felsic core units is completely obscured, and is represented by distinctive low-lying swales. A series of radial dikes punctured the mafic units, beginning in the felsic zone and terminating at the outer border of the intrusion.