At what time in Earth's history do some geologists speculate that Earth was completely covered in ice?
A)1)8 to 0.01 million years ago (Pleistocene)
B)300 to 250 million years ago (Pennsylvanian-Permian)
C)750 to 600 million years ago (late Proterozoic)
D)4)5 to 4.0 billion years ago (Hadean)

Question

Quizplus · Accepted Answer

The period 750 to 600 million years ago, known as the late Proterozoic, is when some geologists speculate that Earth experienced the "Snowball Earth" phenomenon, where it was completely or nearly completely covered in ice.

At What Time in Earth's History Do Some Geologists Speculate