Answer:
2.compare a layer at one location to layers at other locations
Explanation:
Comparing rock layers in distant places can be a challenge for geologists since these layers may have different environmental factors that caused different transformations in them.
Therefore, when it is necessary to establish a comparison between layers of rocks in different ligands, geologists must establish steps to make an efficient comparison and have results consistent with reality. To do this, they must first compare a layer in one location with layers in other locations, assign relative age to a layer in one location, and identify index fossils in one or more layers in one location.
Answer:
Examples of microorganisms include bacteria, archaea, algae, protozoa, and microscopic animals such as the dust mite.
Explanation:
Answer: changed by molecular oxygen
Explanation:
Biologically induced molecular oxygen (dioxygen, O2) started to accumulate in Earth's atmosphere and changed Earth's atmosphere from a weakly reducing atmosphere to an oxidizing atmosphere.
