Greenstone Abstract
Water-bathed greenstone makes for a somewhat artsy, abstract photo. The rock is exposed at the base of a small cliff along the shore of Lake Superior in Presque Isle Park, Marquette, Michigan. (The moving water does not allow great sharpness, but I thought it made a nice natural abstract.)
Greenstone is a low-grade regional metamorphic rock that was most likely basalt originally. The green color comes from the ferrous-iron in the minerals chlorite, actinolite and epidote. The rock is spheroidally-altered to secondary rust-colored minerals around the core of greenstone. The white veins are quartz. The rock is Precambrian in age.
PKF10213 c2
Greenstone Abstract
Water-bathed greenstone makes for a somewhat artsy, abstract photo. The rock is exposed at the base of a small cliff along the shore of Lake Superior in Presque Isle Park, Marquette, Michigan. (The moving water does not allow great sharpness, but I thought it made a nice natural abstract.)
Greenstone is a low-grade regional metamorphic rock that was most likely basalt originally. The green color comes from the ferrous-iron in the minerals chlorite, actinolite and epidote. The rock is spheroidally-altered to secondary rust-colored minerals around the core of greenstone. The white veins are quartz. The rock is Precambrian in age.
PKF10213 c2