1887
PDF

Abstract

Summary

Hopanoids are among the most common biomarkers in fossil sediments and thus serve as a tool to reconstruct paleoenvironmental conditions. Despite their high abundance and compositional variability in sediments, coals and oils, their precursor organisms are often hard to distinguish. Although the diagenetic fate of hopanoids remains partially unresolved, their distributions and degrees of isomerization are widely applied in maturity assessment and palaeoenvironmental reconstruction. To investigate sources and diagenetic pathways of a variety of hopanoids co-occurring in a single sample, we analysed immature sediments from the Early Toarcian (∼183 Ma). Here, we present a suite of hopanoids forming a diagenetic continuum comprised of hopanoid species within a sedimentary succession of identical maturity. The diverse hopanoid inventory hosts aliphatic (neohop-13(18)-enes, hop-17(21)-enes, hopanes), aromatic (benzohopanes, diaromatic 8(14)-secohopanes, tri- and tetra-aromatic hopanes) functionalized (hop-17(21)-enoic acids, hopanoic acids) and thio-hopanoids (hop-17(21)-ene thiolanes, hopane thiolanes, hopane thiophenes), several of which have not been previously reported. Most of these hopanoids are present as A-ring methylated analogues. Here, for hopanoids occurring as 2-methyl hopanoids, the C33 homologues are especially abundant and yield high 2a-methyl/(2a-methyl + desmethyl) ratios, pointing to a common precursor biohopanoid, which may be especially abundant in cyanobacteria and/or nitrogen cycle affiliated a-proteobacteria.

© EAGE Publications BV
Loading

Article metrics loading...

/content/papers/10.3997/2214-4609.202533049
2025-09-07
2026-02-15

  • From This Site

    /content/papers/10.3997/2214-4609.202533049
    dcterms_title,dcterms_subject,pub_keyword
    -contentType:Journal -contentType:Contributor -contentType:Concept -contentType:Institution
    10
    5
Loading full text...

Full text loading...

/deliver/fulltext/2214-4609/2025/imog-2025/49.html?itemId=/content/papers/10.3997/2214-4609.202533049&mimeType=html&fmt=ahah

References

  1. Farrimond, P., Head, I., Innes, H., 2000. Environmental influence on the biohopanoid composition of recent sediments. Geochimica et Cosmochimica Acta64, 2985–2992.
     [Google Scholar]
  2. Köster, J., van Kaam-Peters, H.M., Koopmans, M.P., de Leeuw, J.W., Sinninghe Damste, J.S., 1997. Sulphurisation of homohopanoids: Effects on carbon number distribution, speciation, and epimer ratios. Geochimica et Cosmochimica Acta61, 2431–2452.
     [Google Scholar]
  3. Ourisson, G., Albrecht, P., Rohmer, M., 1979. The Hopanoids: palaeochemistry and biochemistry of a group of natural products. Pure and Applied Chemistry51, 709–729.
     [Google Scholar]
  4. Peters, K.E., Moldowan, J.M., Walters, C.C., 2005. The biomarker guide, 2. ed., repr. with corr., digitally print. version ed. Cambridge Univ. Pr, Cambridge.
     [Google Scholar]
  5. Schaeffer, P., Fache-Dany, F., Trendel, JM., Albrecht, P., 1993. Polar constituents of organic matter rich marls from evaporitic series of the Mulhouse basin. Organic Geochemistry20:1227–1236.
     [Google Scholar]
  6. Schaeffer, P., Adam, P., Philippe, E., Trendel, J.M., Schmid, J.-C., Behrens, A., Connan, J., Albrecht, P., 2006. The wide diversity of hopanoid sulfides evidenced by the structural identification of several novel hopanoid series. Organic Geochemistry37, 1590–1616.
     [Google Scholar]
  7. Seifert, W.K., Moldowan, J., 1980. The effect of thermal stress on source-rock quality as measured by hopane stereochemistry. Physics and Chemistry of the Earth12, 229–237.
     [Google Scholar]
  8. Sinninghe Damsté, J.S., Rijpstra, W.C., Leeuw, J.W. de, Schenck, P., 1989. The occurrence and identification of series of organic sulphur compounds in oils and sediment extracts: II. Their presence in samples from hypersaline and non-hypersaline palaeoenvironments and possible application as source, palaeoenvironmental and maturity indicators. Geochimica et Cosmochimica Acta53, 1323–1341.
     [Google Scholar]
/content/papers/10.3997/2214-4609.202533049
Loading

Most Cited This Month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error