In contrast to the Proterozoic, Archean rocks are often heavily metamorphized deep-water sediments, such as graywackes, mudstones, volcanic sediments and banded iron formations. Greenstone belts are typical Archean formations, consisting of alternating high- and low-grade metamorphic rocks. The high-grade rocks were derived from volcanic island arcs, while the low-grade metamorphic rocks represent deep-sea sediments eroded from the neighboring island frogs and deposited in a forearc basin. In short, greenstone belts represent sutured protocontinents.
What type of formation is indicated by low and high grade metamorphic rocks?
Greenstone
Greenstone belts are typical Archean formations, consisting of alternating high- and low-grade metamorphic rocks.
Greenstone belts are typical Archean formations, consisting of alternating high- and low-grade metamorphic rocks.
What type of formation is indicated by low and high grade metamorphic rocks?