Senin, 10 Desember 2012

Coal-forming material



Almost all of the coal-forming plants. The types of plants and coal-forming age by Diessel (1981) are as follows:
-Algae, from Pre-Cambrian Times to the Ordovician and single-celled. Very few coal deposit of this period.
-Silofita, from the Silurian Period to the Middle Devon, is derived from algae. Few coal deposit of this   
 period.
-Pteridofita, age of Upper Devonian to Upper Carboniferous. The main coal-forming material from Carbon  
 in Europe and North America. Plants without flowers and seeds, spores multiply and grow in warm 
 climates.
-Gimnospermae, a period ranging from Permian to Cretaceous Middle Ages. Heterosexual plants, seeds  
 encased in fruit, such as pine, contain high levels of sap (resin) high. Type Pteridospermae like  
 gangamopteris and Glossopteris is the main constituent Permian coal as in Australia, India and Africa.
-Angiosperms, from the Upper Cretaceous period until now. Modern plants, the fruit covering the seeds, the  
 male and female in one flower, less gummy than gimnospermae so that, in general, less well preserved.

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