Life on Rocks

Question 1

When was water on Earth by?

Answer 1

By 4.2-4.3 BYA.

Question 2

What might be the oldest fossil?

Answer 2

Iron oxide tubes created by iron-oxidizing bacteria found at Nuvvuagittuq Gneiss.

Question 3

What are the two problems with the Iron oxide tubes created by iron-oxidizing bacteria found at Nuvvuagittuq Gneiss?

Answer 3

1. Age not clear. 2. The oxide tubes might not need biology.

Question 4

What percent of geologist think that the iron oxide tubes found at Nuvvuagittuq Gneiss are the oldest fossil?

Answer 4

30 percent.

Question 5

How old are the oldest fossils (Iron oxide tubes created by iron-oxidizing bacteria found at Nuvvuagittuq Gneiss believed by some to be)?

Answer 5

3.77-4.3 BYA.

Question 6

How old are the stromatolite found in Greenland proposed to be?

Answer 6

3.7 BYA.

Question 7

What percent of geologists believe the stromatolites in Greenland are 3.7 BYA?

Answer 7

70%.

Question 8

What is the problem with the stomatolite fossils found in Greenland?

Answer 8

They were only found in one location, so there is no paleoenvironmental context.

Question 9

When are the first microfossils proposed to have appeared on Earth?

Answer 9

By 3.4-3.5 BYA.

Question 10

What percent of geologists believe that microfossils appeared on Earth 3.4-3.5 BYA?

Answer 10

50%.

Question 11

When did stromatolites appear in the fossil record (not Greenland stormatolites).

Answer 11

By 3.4-3.5 BYA.

Question 12

What percent of geologist believe that stromatolites appear in the fossil record around 3.4-3.5 BYA? (Not Greenland).

Answer 12

99%.

Question 13

When did the first huge fossils appear in the fossil record?

Answer 13

3.2 BYA.

Question 14

How many geologists believe that huge fossils appear in the fossil record around 3.2 BYA?

Answer 14

50%.

Question 15

What were the two problems with the huge fossils proposed to be around 3.2 BY old? What could they be?

Answer 15

1. Not found in any other units. 2. Can not confirm original locality. 3. Possible eukaryotes.

Question 16

How old is the oldest rock on Earth?

Answer 16

3.96 BY old.

Question 17

Where was photosynthetic carbon found? How old is it proposed to be?

Answer 17

In Akilia Island, Greenland. Proposed to be 3.85 BY old.

Question 18

How many geologists believe the 3.85 BYO photosynthetic carbon found in Akilia Island, Greenland is true?

Answer 18

10%, because of the Steve Mojzsis controversy.

Question 19

Evidence for stromatolites without oxygen were proposed to be how old? Why do they think they were anoxygenic?

Answer 19

3.4-3.5 BYO. They used uranium and iron isotopes.

Question 20

How many geologists accept the evidence for stromatolites without oxygen? Why?

Answer 20

50%, because it is a new technique that needs to be verified.

Question 21

When is the first proposed evidence of oxygen in the ocean and where was it found?

Answer 21

3.2 BYO, in South Africa.

Question 22

How many geologists believe there is evidence of oxygen in the ocean by 3.2BYA? Why?

Answer 22

About 50% since they used uranium and iron isotopes, which is a new technique.

Question 23

How old are the molecular biomarkers indicating cyanobacteria and eukaryotes and where were they found?

Answer 23

Proposed to be 2.7 BYO. They were found when drilling in South Africa.

Question 24

How many geologists believe the molecular biomarkers indicating cyanobacteria and eukaryotes are 2.7 BYO?

Answer 24

Around 10% unless new drilling shows positive results.

Question 25

What is the problem with the earliest micro-fossils?

Answer 25

Found in the Schopf locality (where the geology doesn’t make sense).