Hilt's Law
Encyclopedia
A geological term that states the deeper the coal
, the deeper its rank (grade). The law holds true if the thermal gradient is entirely vertical, but metamorphism may cause lateral changes of rank, irrespective of depth. Increasing depth of burial results in a decrease in the oxygen
content of the coals. The phenomenon was observed by professor Carl Hilt (1873).
Coal
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure...
, the deeper its rank (grade). The law holds true if the thermal gradient is entirely vertical, but metamorphism may cause lateral changes of rank, irrespective of depth. Increasing depth of burial results in a decrease in the oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
content of the coals. The phenomenon was observed by professor Carl Hilt (1873).