What are the two main sources of Earth’s internal heat? a.) radioactive decay and residual heat leftovers from Earth’s formation

b.) Earth’s magnetic field and turbidity currents

c.) isostasy and sublimation of iron in Earth’s core

d.) radioactive decay and isostasy

a.) radioactive decay and residual heat leftovers from Earth’s formation

I think-

not completely sure but i think it’s many moons, smaller in size and a ring system.

the precambrian aged rocks could be found in australia. australia is a region that has a lot of ancient civilization history from million years ago. in this region, there are a lot of recognizable fossils buried in its land which is considered a precambrian-aged rocks