Composition of resinites from the Eocene Geiseltal brown coal basin, Saxony-Anhalt, Germany and comparison to their possible botanical analogues. (February 2021)

• Record Type: Journal Article
• Authors: Simoneit, Bernd R.T.; Otto, Angelika; Menor-Sálvan, Cesar; Oros, Daniel R.; Wilde, Volker; Riegel, Walter
• Is Part Of: Organic geochemistry. Volume 152(2021)
• Publication Date: 2021-02
• Subjects: Geiseltal -- Terpenoid natural products -- Resinites -- Paleobiome biomarkers -- Chamaecydins -- Amber; Organic geochemistry -- Periodicals; Biogeochemistry -- Periodicals; Géochimie organique -- Périodiques; 553.205
• DOI: 10.1016/j.orggeochem.2020.104138
• Languages: English
• ISSNs: 0146-6380

Abstract

Highlights: The Geiseltal resinites are well-preserved, pre-amber fossil resins of 43–49 Ma age. Resins have conifer ( Taxodium ) and angiosperm (Burseraceae, Dipterocarpaceae) origins. Possible Taxodium resin is enriched in chamaecydins. Possible angiosperm resins are rich in triterpenediols, amyrins and ursolic acid. Species and diagenetic pathways from precursors to the products in resins are suggested. First structural confirmation of 12-hydroxysimonellite by proton NMR spectroscopy. Abstract: The former lignite pits of the Geiseltal in Saxony-Anhalt, Germany, were an important source of well-preserved Eocene animal and plant fossil remains, including resinites (fossil resins) from different botanical sources. We studied three different types of resinites with distinct morphological characteristics, collected at one of the Geiseltal pits, elucidated their molecular compositions and identified the main biomarker and natural product compounds present. The excellent preservation of molecular markers in the resinites, not yet consolidated to amber despite their middle Eocene age, allowed us to perform chemotaxonomic assignments by correlation with the natural product compositions of extant plant resins. The results showed that the main botanical contributors to the Geiseltal paleoenvironment were conifers of the Cupressaceae family, pointing to the genus Taxodium by the major presence of chamaecydin, ferruginol, 7α- p -cymenylferruginol and taxodione. The compositions found for two other Geiseltal resinite types suggested an angiosperm origin, compatible with the Burseraceae family and the genera Shorea or Hopea of the Dipterocarpaceae as botanical sources. The results support the theory that this Eocene paleobiome was a semitropical swamp and they provide new data for the diagenetic routes of terpenoid natural products.