Messel Oil Shale Research Articles

New aspects on the formation of hydrocarbon source rocks

Episodic volcanism favors, as shown by examples from Europe, the USA, and Brazil, the formation of organic-rich sediments (hydrocarbon source rocks). The examples examined from Europe comprise the Lower Carboniferous Oil-Shale Group, Scotland; Upper Carboniferous Coal Measures, western Germany; Upper Jurassic Kimmeridge Shale, North Sea area; Lower Cretaceous Blattertonstein, northwest Germany; and Eocene Messel Oil Shale, Rheingraben. Examples from the USA are Devonian/Mississippian Gas Shales, Permian Phosphoria Shale, Middle Cretaceous Mowry Shale, Eocene Green River Shale, and Miocene Monterey Shale. Examples from Brazil are Permian Irati Oil Shale and Oligocene Paraiba-Valley Oil Shale. Volcanism is reflected during sedimentation (1) by exhalation of SO2 and/or CO2, (2) volcanic ashfalls, (3) by generation of anoxia and preservation of organic matter, and (4) by halmyrolytic alteration of volcanic ashes into highly surface-active clay minerals (montmorillonite).

Identification of polar porphyrins in oil shale

Several porphyrin acids [(1)–(6); C30–C33] have been isolated from the Messel oil shale and identified by nuclear Overhauser effect studied and synthesis; they imply the existence of several diagenetic pathways leading from the chlorophylls to the alkylpetroporphyrins.

A novel chlorophyll c related petroporphyrin in oil shale

A novel C 31 nickel petroporphyrin skeleton, 15,17-(15 2-methyl)ethano-3,8-diethyl-2,7,12,18-tetramethylporphyrin 3, related to chlorophyll c, has been isolated from the Messel oil shale, and it structure determined by selective decoupling and nuclear Overhauser effect studies.

In situ metal-staining of biological membranes in sediments

Decomposition of organic matter in sediments is principally mediated by bacteria and burrowing organisms. During this process, organic matter undergoes a series of structural chances in which heavy metals and minerals actively participate1–4. Metal–organic complexes arise which are instrumental in crystal seed formation and growth of authigenic minerals such as sulphides, phosphates, oxides and carbonates. By means of transmission electron microscopy, modern organic-rich sediments from the Black Sea and Lake Tanganyka and samples from Eocene Messel oil shale in Germany were studied for the presence of heavy metal stained biological membranes. We report here that during early diagenesis heavy metals seem to supplant hydrogen, alkali and alkaline-earth ions placed at the surfaces of membranes in living organisms. The resulting patterns are the same as those found in organic tissues which before electron microscopy were stained with lead, uranium and osmium salts. In sediments, naturally stained membranes can further act as templates for mineral deposition and may—in certain environmental conditions—lead to strata-bound ore deposits.

Molecular fossils of Archaebacteria as selective degradation products of kerogen

A mixture of alkanes is obtained by treatment of the kerogen from the lacustrine Messel oil shale (Eocene) with boron tribromide, followed by the reduction of the released bromides with lithium aluminum hydride (or deuteride). The n-alkanes (C28C34) show a high even predominance. They correspond to long-chain diols from higher plants, which are linked to the kerogen as diethers or diesters. The branched and cyclic alkanes show a relatively simple pattern, between C15 and C40, corresponding to long-chain, slightly branched and isoprenoid hydrocarbons. Anteisopentadecane, C15H32, 8, isopentadecane, C15H32, 7, and its dimer, 13,16-dimethyloctacosane, C30H62, 9, as well as phytane, C20H42, 5, its dimer bis-phytanyl, C40H82, 2 and another isoprenoid compound, C40H80, 3, with 1 5-membered ring, have been idenified as major components by comparison with standards. The C15 and C30 compounds are attached to the kerogen as alcohols and diols implied in ether or ester linkages. The structural identity of the C20 and C40 compounds with those obtained recently by a similar sequence from Archaebacteria, clearly suggests that molecular entities of these micro-organisms, especially of methanogens, are incorporated in the kerogen as mono- and α,ω-diethers. It could also mean that the cell membranes of these bacteria are an integral part of the kerogen.

Aromatic hydrocarbons from geological sources—I : New naturally occurring phenanthrene and chrysene derivatives

The phenanthrene and chrysene derivatives 1 and 2 have been identified in the Messel oil shale by comparison with synthesized reference compounds. These molecules have most probably been formed by progressive geochemical aromatization of triterpene precursors of the hopane series which is widespread in the geological environment.

Tri- and tetraterpenoid hydrocarbons in the Messel oil shale

The high molecular weight constituents of the branched and cyclic hydrocarbon fraction of the Messel oil shale (Eocene) have been examined by high resolution gas chromatography and combined gas chromatography-mass spectrometry. The following compounds are present: perhydrolycopene (1; lycopane), together with one or more unsaturated analogues with the same skeleton; a series of 4-methylsteranes (2c) in higher abundance than their 4-desmethyl analogues; two series of pentacyclic triterpanes, one series (C 27-C 32) based on the hopane structure (3a-e), and the other (C 27-C 31) based on the 17α-H hopane structure (3a-d, 17αH); and an intact triterpene hop-17 (21)-ene [3c, Δ 17(21)]. Only two additional triterpanes were detected in minor concentrations, viz. 30-normoretane (3b, 21αH) and a C 31 triterpane based on the hopane/lupane-type skeleton. The presence of these compounds suggests a significant microbial contribution to the forming sediment. Comparison of the tri- and tetraterpenoid hydrocarbons with those of the Green River Shale indicates differences in the organisms contributing to the two sediments.

Polycyclic Hydrocarbons in Oil Shale--Origin and Geochemical Fate: ABSTRACT

A series of pentacyclic triterpenes of the hopane type is present as the main components of the polycyclic hydrocarbon fraction of the Messel oil shale, a terrestrial sediment of Eocene age, from near Darmstadt, Germany. The series ranges from C27 to C32, and the members differ only by the length of the side chain on the 5-membered ring. The C27, C31, C32 compounds, which have never been detected in nature, probably arise from geomicrobiological degradation and alkylation reactions of a C30 precursor taking place in the first stages of sedimentation. Pentacyclic triterpenes usually have been considered as paleoecologic makers indicating a higher plant origin of part of the organic matter of sediments and pe roleum. Recent studies, however, on the chemistry of bacteria and blue-green algae have shown that these sources do contain pentacyclic triterpenes, commonly in significant amounts, and that these triterpenes are of the hopane type. These results, combined with analysis of the olefinic and oxygenated polycyclic fractions of the shale, seem to indicate a prokaryotic origin of the triterpenes isolated from the Messel oil shale. Moreover, analysis of the polycyclic hydrocarbons isolated from several recent and ancient sediments, as well as from crude oils, shows that triterpenes of the hopane type are widely present in these sources, and suggests that a significant proportion of the triterpenes found in sediments and oil in general could be of prokaryotic origin. End_of_Article - Last_Page 766------------

Homohopane in messel oil shale : First identification of a C 31 pentacyclic triterpane in nature Bacterial origin of some triterpanes in ancient sediments?

Homohopane in messel oil shale : First identification of a C 31 pentacyclic triterpane in nature Bacterial origin of some triterpanes in ancient sediments?

Triterpene Alcohol Isolation from Oil Shale

Isoarborinol, an intact pentacyclic unsaturated alcohol, was isolated from the Messel oil shale (about 50 x 106 years old). Complex organic substances, even those very sensitive to oxidation, reduction, or acidic conditions, can thus survive without alteration for long periods.

Zur Tektonik des Ölschiefervorkommens von Messel bei Darmstadt

Zur Tektonik des Ölschiefervorkommens von Messel bei Darmstadt