Many forms of rock alteration can be seen in the TGB.
Its overall structure has attained greenschist grade metamorphism, even though amphibolite grade metamorphism surrounds the Chambers-Strathy Batholith.
The metamorphism that creates greenschist is minimal in contrast to that which creates rocks such as gneiss.
Other rock alterations include small veins of quartz and epidote, vesicles filled with quartz, calcite and chlorite, extensive replacement of volcanic rock by silica or calcite, and calcite precipitation in extension fractures.

Outcrops of silicified mafic pillow lava are found along and west of the Ontario Northland Railway, east of the Big Dan Shear Zone and adjacent to Outlet Bay and Boot Bay of Net Lake.
This form of alteration occurs in deformation zones and is the product of low temperature seawater alteration.
Volcanic rock replaced by carbonate is commonly found in the Northeast Arm Deformation Zone, the Link Lake Shear Zone and in the Net Lake-Vermilion Lake Deformation Zone.
Within the high strain zones, carbonate is also manifest as 1 m (3.3 ft) wide veins that have been traced along strike for more than 100 m (330 ft).

Basalt has been replaced by calcite in a restricted area just north of the Temagami's former garbage dump.
Although developed adjacent to the Link Lake Shear Zone, rocks within and just outside the calcite alteration zone do not normally contain significant foliation.
Thus, if the calcite alteration zone was located within the Link Lake Shear Zone, it did not form inside the zone of the highest strain.
Many forms of rock alteration can be seen in the TGB. Its overall structure has attained greenschist grade metamorphism, even though amphibolite grade metamorphism surrounds the Chambers-Strathy Batholith. The metamorphism that creates greenschist is minimal in contrast to that which creates rocks such as gneiss. Other rock alterations include small veins of quartz and epidote, vesicles filled with quartz, calcite and chlorite, extensive replacement of volcanic rock by silica or calcite, and calcite precipitation in extension fractures.
Outcrops of silicified mafic pillow lava are found along and west of the Ontario Northland Railway, east of the Big Dan Shear Zone and adjacent to Outlet Bay and Boot Bay of Net Lake. This form of alteration occurs in deformation zones and is the product of low temperature seawater alteration. Volcanic rock replaced by carbonate is commonly found in the Northeast Arm Deformation Zone, the Link Lake Shear Zone and in the Net Lake-Vermilion Lake Deformation Zone. Within the high strain zones, carbonate is also manifest as 1 m (3.3 ft) wide veins that have been traced along strike for more than 100 m (330 ft).
Basalt has been replaced by calcite in a restricted area just north of the Temagami's former garbage dump. Although developed adjacent to the Link Lake Shear Zone, rocks within and just outside the calcite alteration zone do not normally contain significant foliation. Thus, if the calcite alteration zone was located within the Link Lake Shear Zone, it did not form inside the zone of the highest strain.
Temagami Greenstone Belt