Context: 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.

Question: What are Archean rocks composed of, in general?
Answer: metamorphized deep-water sediments

Question: What type of formation is indicated by low and high grade metamorphic rocks?
Answer: Greenstone

Question: From where did high grade Archean rocks originate?
Answer: volcanic island arcs

Question: Low grade metamorphic rocks are composed of what, generally?
Answer: deep-sea sediments

Question: What is a greenstone belt?
Answer: sutured protocontinents

Question: What kind od sediments where Proterozoic rocks made from?
Answer: Unanswerable

Question: What kind od belts often formed during the Proterozoic period?
Answer: Unanswerable

Question: What single type of rock formed Greenstone belts?
Answer: Unanswerable

Question: What kind of volcanic rock formed low-density metamorphic rock?
Answer: Unanswerable

Question: What kind of sediment formed high-density metamorphic rock?
Answer: Unanswerable