So, grains of quartz are weathered out of the granite, eroded, and carried away to some low-lying area, maybe the continental shelf. The quartz grains settle and accumulate, becoming...
5.
Geologic Materials
Weathered
Continental Crust or
Volcanic Island Arc,
Deposited
Sediment
Sedimentary
Rock
Metamorphic
Rock
Granitic
Magma
Plutonic
Igneous Rock
(Granite)
Plutonic
Igneous Rock
(Gabbro)
Oceanic Crust
(Mainly Basalt)
Mantle
Rock
Basaltic
Magma