What is not true about the archean eon?
a. oldest fossil is found from this time period
b. formation of earliest solid rock
c. oxygen begins to appear in the atmosphere
d. spanned from about 3.8 billion to about 2.5 billion years ago

D. Spanned from about 3.8 billion to about 2.5 billion year ago

Explanation:

The Archean eon expanded from 4 billion years ago, until 2.5 billion years ago, being predeceased by the Hadean eon, and being followed by the Proterozoic eon. During this eon there were numerous very important things that happened. The first solid rocks were formed, thus the basis for the first continents arrived on the scene. The oldest fossils of living organisms are also dated to this eon, and they were the ones that started to slowly change the atmosphere by introducing free oxygen molecules to it.

events in order:

1.       vishnu schist

2. zoroaster granite

3. bass limestone

4. hakatar   shale

5. igneous intrusion

6. shinumo quartzite

7. dox sandstone

8. tapeats limestone

9. bright angel shale

10. muav limestone

11. temple butte limestone

12. redwall limestone  

nonconformity

answer: the unkar group shows angular unconformity because the layers are turned at angle.

unconformity

answer: specifically the angular unconformity occurs between the cambrian and precambrian rocks. the dox sandstone, shinumo quartzite, hakatar shale, and bass limestone have been filled. an angular unconformity occurs between the cambrian and precambrian rocks. the dox sandstone, shinumo quartzite, hakatar shale, and bass limestone have been filled.

disconformity

answer: the disconformities aremarked irregular lines between the sedimentaryrocks layers.