The oldest zircons from Australian sandstone were formed when the Earth formed it oldest continental crust and must have derived from what type of rock?

Question

Quizplus · Accepted Answer

Zircons can only form in rocks with high silica content and low amounts of other elements, such as iron and magnesium. Basalt and peridotite are both low in silica, while rhyolite is high in silica but was not present during the formation of the Earth's oldest continental crust. Granite, on the other hand, has a high silica content and was present during the formation of the Earth's oldest continental crust, making it the most likely candidate for the source of the zircons in Australian sandstone.

The Oldest Zircons from Australian Sandstone Were Formed When the Earth