Shale Messel

Table 3.3 5 C-values of separated individual hydrocarbons from the Messel shale (Freeman...

Kimble BJ, Maxwell JR, Philp RP, Eglinton G, Albrecht P, Ensminger A, Arpino P, Ourisson G, Tri- and tetraterpenoid hydrocarbons in the Messel oil shale, Geochim Cosmochim Acta 38 1165—1181, 1974. 

Schaeffer, P. Trendel, J.-M. Albrecht, P. (1995) Stmcture and origin of two triterpene-da ived aromatic hydrocarbons in Messel shale. J. Chan. Soc., Chem. Commun., 1275-6. 

Tetracyclic terpene from Eocene Messel shale (Germany) can be also synthesized by using the LBA-induced enantioselective cyclization of 3-homofarnesyltoluene as a key step (eq 16). 

Figure 14 shows the C27 and the C29-C32 terpane m/e 191 mass chromatographic profiles for the five coals. Their mass spectra match those of the hopane series found abundant in Messel shale (6). The C27 and C29-C30 hopanes were confirmed by coinjection with the authentic hopanes. Note the decrease in relative concentration with the maturity of the 17- H C27, C29, and C30 hopanes (7). This is further confirmation of the thought that the 17-y3H hopanes are thermodynamically less stable than the 17- H, 21- H series. The ratios of the 17-/3H series to the 17-aH series may be reliable indicators of the maturity of a deposit. This may be complicated by the chance that the relative intensities within a series may carry some information about environmental conditions at the time of formation of a deposit. 

Only one methyl-sterane, C nH, was identified. 4-Methyl-steranes have been identified earlier in the Messel shale (10) ... 

According to the identified tetraterpane, the Aleksinac shale is more like the Eocene Green River shale, which also contained perhydro-8-carotane (5,13), than like the Miocene Messel shale in which acyclic lycopane has been identified (10). These differences probably originate from different participation of various carotenoids in the biolipids whose remains were precipitated with the sediments. 

The content of humic acid and fulvic acid in these shales was extremely low (0.4% humic carbon/total carbon for the Green River shale and 6.1% for the Messel shale), and the ratio of fulvic acid to humic acid was 0.28 for the Messel sample. 

Table 5.9 Carbon isotopic composition of some compounds in the Eocene Messel Shale (data after Freeman et al. 1990)...

Abbott G.D., Bashir F.Z., Sugden M.A. (2001) Kerogen-bound and free hopanoic acids in the Messel oil shale kerogen. Chirality 13, 510—16. 

HayesJ.M.,Takigiku R., Ocampo R., Callot H.J., Albrecht P. (1987) Isotopic compositions and probable origins of organic molecules in the Eocene Messel shale. Nature 329, 48-53. 

Hopane and homohopane (180) have been identified in Messel oil shale. The structure of homohopane was confirmed by a partial synthesis from diplop-tene [hop-20(29)-ene]. It is suggested that homohopane arises by microbiological methylation and that a significant proportion of the triterpanes found in sediments and oils are of bacterial origin. Tetrahymanol (181) has been isolated from Green River Shale. 

Porphyrin Handbook Vol 1. Academic Press, San Diego, San Francisco, New York, Boston, London, Sydney, Toronto c) Ocampo R, Bander C, Callot HJ, Albrecht P (1992) Porphyrins from Messel oil shale. Geochimica et Cosmochimica Acta 56 745... 

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