COALIFICATION USUALLY VEGETAL SUBSTANCES OR PLANT PIECES ACCUMULATE IN PROPER MARSH AREAS AND PRECIPITATE AND ARE BURIED UNDER GROUND WITH GEOLOGICAL FUNCTIONS.AFTER THESE ORGANIC MASSES ARE BURIED UNDER GROUND,THEY ARE EFFECTED FIRST BY THE PRESSURE CIRCUMTANCES, AND LATER BY THE ENVIRONMENTAL HEAT-CIRCUMTANCES.DUE TO THESE CIRCUMTANCES,SOME CHANGINGS HAPPEN IN THE STRUCTURES OF THE ORGANIC SUBTANCS.FIRSTLY,THESE ORGANIC SUBTANCES ,WHICH ARE CALLED ''PEAT'' AND KNOWN AS ANCESTORS OF THE COALS,HAVE DARKER COLORS AND MORE RIGID STRUCRURES IN TIME.IN THE RESULT OF HEAT AND PRESSURE EFFECT THESE MASSES ;IN ORDER,FIRST WATER AND STREAM ,CARBON DIOXIDE (CO2),OXIGEN (O2) (AT THE STAGE OF PEAT TO BITUMINOUS COAL ) AND THEN IN THE FURTHER STAGES , HYDROGEN (H2) LEAVE (ANTRASITE- STAGE ). AND SURELY IN THIS PERIOD , IDEAL CIRCUMTANCES AND HEAT CIRCUMTANCES OF THE ENVIROMENT SHOULD BE DOMINANT FOR A LONG TIME (THOUSAND YEARS ) INCREASING CONTINUALLY. THE HEAT OF THE GROUND IS INCREASED 10 C DEGREE AT EVERY 30 METERS DOWNWARD. THEREFORE CERTAINLY,THE HEAT-INCREASING IS NEEDED FOR IDEAL AND NORMAL CIRCUMTANCES. WHEN THE HEAT INCREASES CONTUNALLY,FIRST THE ORGANIC SUBSTANCE NAMED ''PEAT'' TURNS INTO LIGNITE;AND THEN INTO SUB-BITUMINOUS COAL,AND THEN INTO BITUMINOUS COAL AND ANTRASITE AND FINALLY INTO GRAPHITE (BLACK LEAD). THIS PROGRESSIVE MATURATION PERIOD IS CALLED ''COALIFICATION'' AND EACH LEVEL OF IT IS CALLED 'COALIFICATION DEGREE'' (RANK). What Is Coal? How It Occurs? The Importance Of Coal Coalification Case 05.09.2010 USA $ Purchase 1.4994 TL Selling 1.5066 TL EURO (€) Purchase 1.9241 TL Selling 1.9334 TL