Geology Reference
In-Depth Information
50
40
Petroleum
30
Hydroelectric
power
Natural gas
20
Coal
Nuclear
electric
power
10
Wood
0
1650
1675
1700
1725
1750
1775
1800
1825
1850
1875
1900
1925
1950
1975
2000
Figure 1.1.2. Energy consumption from 1635 to 2006. From EIA 2006, Figure 5
.
In the early Carboniferous, coal swamps were found primarily in the low-latitude areas. In the later Carboniferous,
a belt of coal swamps extended from the mid-western United States through Europe to Africa. Another coal belt
extended from the Donets Basin of Russia to Morocco. In China and Mongolia, coals and interbedded marine
sediments are related to the mid-Carboniferous transgression and regression of a broad seaway (Tatsch, 1980).
Terrestrial plants had been developing for 100 million years, and by the Carboniferous, plants adapted to
semiaquatic or marshy areas were abundant. The majority of coal-forming plants were fern-like pteridophytes,
such as the calamites (Figure 1.1.3), smaller plants, 4.5
12m high that formed dense jungles, similar to canebrakes.
The lycopodia or club mosses, lepidodendra and sigillaria, grew to over 30m and had diameters in excess of 1.2m.
Spermatophytes of the period included cordaties, a tall slender tree that may have been an upland plant whose
leaves were carried by streams into the peat swamp (Edmunds, 2002; Janssen, 1939; Kummel, 1961).
-
Lepidodendron
Cordaites
Sigillaria
Calamites
Figure 1.1.3. Carboniferous coal-forming plants. From Edmunds 2002, with permission.
