What was the likely composition of Earth's early crust (how did crustal composition evolve)?

Question

Was the first crust entirely mafic (oceanic) crust which was later distilled via volcanic arcs along subduction zones to make felsic rocks or did the earth start with bits of felsic crust?Are the ancient zircons most likely from felsic or mafic rocks?

Answer 1

Earth's early crust would have lacked oxygen as most of the planet's oxygen is produced as a by product of organic respiration.