Black Earth: World of Coal

Question 1

How does coal form

Answer 1

Coal starts off as peat which gets buried as a sediment

Question 2

When did the carboniferous period occur

Answer 2

360 to 300 million years ago

Question 3

The carboniferous period was when what occured?

Answer 3

most coal formed
The coal-bearing rocks are Upper carboniferous

Question 4

What did the contients and climate look like during the Carboniferous

Answer 4

Gondwana and Laurussian land masses formed the supercontient Pangea
There was a very wide tropical belt

Question 5

What is the significance of the Carboniferous period
Hint’ coal

Answer 5

Coal has deposited in all geological periods since Carboniferous, but most was deposited in the Carboniferous
The question is why?

Question 6

All land plants stem from

Answer 6

Green Algae
The Charophyceae, fresh water green algae, are closest relatives of land plants
They live in water so don’t need specilised fluid/gas transport system
Around 540Mya

Question 7

What is a Vascular plant

Answer 7

One which has evolved a system to transport and conduct water
Early land plants (mosses, liverworts + hornworts) had waxy cuticle to prevent drying out, they lacked true vascular tissue to carry water. Instead water was captured as it ran over the plant’s surface

Question 8

What is special about plants evolutionary tree

Answer 8

Plants are very evolutionary conservative: most major plant groups live and evolve on till today (bar two)

Question 9

A Liverwort plant is an example of Bryophyte group and is one of the most primitive
What is special about this plant

Answer 9

Liverworts have pores of their surface but lack stomata

Question 10

What is the Oldest extant group of Vascular plants and their link to the Carboniferous

Answer 10

Lycophytes are the oldest extant group of vascular plants
In the Carboniferous, some were forest-forming trees

Question 11

What are Gymnosperms and their link to the Carboniferous

Answer 11

Gymnosperms coexisted early with brophytes, ferns and other seedless plants which took off in the carboniferous
Literal translation - naked seed

Question 12

One of the last groups to come into existance was the Angiosperms
These were

Answer 12

Flowering plants which close their seeds in fruit
They radiated during the Mesozoic (dinosaur time)

Question 13

What plants where highly preserved from the carboniferous and why

Answer 13

Fossil plants of Sphenopsides (found streamside), Lycopsids (found in water) and Ferns (found in disturbed environments) were mostly preserved
Preservation is highest on swampy ground, because waterlogging inhibits decay and the other environments are often erosional

Question 14

Why did Lycopsids fossilise well

Answer 14

Carboniferous lycopsids kept upright by very thick bark
They were waterproof, decay-resistant, bug resistant bark, which was very thick allowing it to become fossilised through the inside then filling up with sediment

Question 15

How does fossilisation occur in classic coastal swamp cyclothem

Answer 15

• Sea level rises, which drows the swamps and hence plants there die due to salt water
• Sand also gets washed in, rising land out of water and plants can grow again
• This changing sea level was due to the wax and wane of Glacial ice melting

Question 16

So what is the reason the Carboniferous produced so much coal
What is the issue with this idea tho

Answer 16

Tropical swamps extensive in the Carboniferous, which lasted a long time, so lots of organic deposits
But swamps are common at many other times in history

Question 17

What are Detritivores

Answer 17

Chop up and digest dead matter, and what is not broken down, is left to decomposers
Mostly found in litter and soil
In the Carboniferous there was no wood-eating beetles, termites, flies, ants etc, so the diversite of detritivores was far less than it is now

Question 18

We can analyse different peats from now and back in the Carboniferous, to look at decomposition
What is the differences seen

Answer 18

More big bits relative to small bits in Carboniferous peats
Suggesting slower decomposition
And more leaves relative to roots in Carbonferous peats, also suggesting slower decomposition. This is due to many detritivores being above ground

Question 19

We can look at the size of borings (holes in wood) between the carboniferous and now to look at the rate of decomposition
What does it show

Answer 19

There has been a large increase in the size of borings in woods between the carboniferou and now
Suggesting slower decomposition in the carboniferous

Question 20

Decomposition leads to carbon being returned into the atmosphere
If rates of decompsition are lower in the carbonferous, what affect does this have

Answer 20

Lots of Carbon was buried but hadn’t come back to the suface to be oxidised as CO₂, which came from lignin in plants
The phosphorus from Lignin fueled productivitiy from the soil, which lead to increased carbon burial in a feedback cycle

Question 21

If lots of carbon is being buried, what its expected to happen to O₂ levels

Answer 21

Oxygen concentration in atmosphere should rise
As other O₂ sinks are full

Question 22

The current % of oxygen in the atmosphere is around 21%
What effect would there be, if this was to rise like it did in the Carboniferous

Answer 22

This would increase susceptibility to spontaneous burning
The Carboniferous marks increases in forest fires due to high levels of oxygen in the atmopshere - negative feedback cycle
This causes coal to increase