| Popis: |
Tasmanian tasmanite, an organic-rich rock of Permian age, is made up of silt and compressed discs of Tasmanites , a unicellular organism with close biological affinity to the present day marine organisms of the genus Pachysphaera . The investigation of the oarboxylic acids extracted from tasmanite and of carboxylic acids derived from the oxidative degradation of the fossil spore walls has been carried out by gas chromatography, high and low resolution mass spectrometry and gas ohromatography-mass spectrometry. Exhaustive extraction yielded mainly normal acids ( C n H 2 n O 2 , n = 5–31) and polycyolic acids, possibly derived from sterol diagenesis. Acids isolated in low concentration after demineralization had essentially the same distribution pattern as the acids derived after saponification, namely normal ( C n H 2 n O 2 , n = 8–22), dicarboxylic ( C n H 2 n -2 O 4 , n = 9–17) and polycyolic acids. The acids produced by stepwise (six steps) oxidation of the kerogen concentrate were quite varied. The major products obtained from the early oxidations consisted of normal ( C n H 2 n O 2 , n = 8–30), dicarboxylic ( C n H 2 n -2 O 4 , n = 10–24), polycyclic and aromatic acids, and from the later oxidations mainly smaller and more polar acids: normal ( C n H 2 n O 2 , n = 9–12), dicarboxylic ( C n H 2 n -2 O 4 , n = 8–12), benzene dicarboxylic ( C n H 2 n -10 O 4 , n = 8–10), benzene tricarboxylic ( C n H 2 n -12 O 6 , n = 9,10) acids. The major findings of these studies are: 1. (1) tasmanite kerogen is constituted mainly of a random, saturated hydrocarbon polymer, probably derived from saturated and olefinic lipids and sterols 2. (2) the isoprenoid acids are absent in both the extracts and oxidation products. |
