The marked rise in oxygen in Earth's atmosphere coincides with the first appearance of _________ in the rock record.
A)banded iron formation
B)red beds
C)eukaryotic algae
D)both B and C

Question

Quizplus · Accepted Answer

The marked rise in oxygen in Earth's atmosphere, known as the Great Oxidation Event, coincides with the first appearance of both red beds (oxidized soils or sediments indicating increased atmospheric oxygen) and eukaryotic algae (organisms that contributed to oxygen production through photosynthesis) in the rock record.

The Marked Rise in Oxygen in Earth's Atmosphere Coincides with the First