Isotopenvariationen des Stickstoffs humoser und bituminöser natürlicher organischer Substanzen

gd¹⁵N-values and nitrogen contents of a series of humic and bituminous organic sediments of different ranks were determined. The change of the isotopic abundance of nitrogen was investigated during heating in model experiments, using a gas flame coal.In the case of humic carbon coals the relative nitrogen contents vary from 0.8 to 1.4% and the δ¹⁵N-values from +3.5 to +6.3%. increasing from the brown coal to anthracite ranks. During the coalification process both the δ¹⁵N-values and the relative nitrogen contents do not vary continuously with the rank, but pass through maxima and minima. Model experiments using a gas flame coal show the same trend. Nitrogen with δ¹⁵N-values of +2.8 or ?7%. was released in pyrolysis experiments, applying a gas flame coal and a steam coal at temperatures of 650 and 1000°C, respectively.The investigated bitmuinous sediments yielded relative amounts of 0.1 to 0.8% with δ¹⁵N-values of + 4.2 to + 10.7%.The obtained results are discussed with respect to the elucidation of nitrogen genesis in natural gas deposits.