25th International Meeting on Organic Geochemistry IMOG 2011

P-281
The significance of novel A-norsteranes and perylene in
Devonian reefs and crude oils
Svenja Tulipani 1 , Kliti Grice 1 , Paul Greenwood 1,2 , Robert Lockhart 1 , Muhammad Asif 3 ,
Kenneth Williford 1 , Arndt Schimmelmann 4
1 WA Organic and Isotope Geochemistry Centre, Applied Chemistry, Curtin University of Technology, Perth,
Australia, 2 University of Western Australia, Perth, Australia, 3 Chemistry Department, University of
Engineering and Technology, Lahore, Pakistan, 4 Department of Geological Sciences, Indiana University,
Bloomington, United States of America (corresponding author:s.tulipani@curtin.edu.au)
Distributions of unusual compounds including a series
of putative C19 A-norsteranes - potential novel sponge
biomarkers originating from stromatoporoids - have
been detected in Devonian sediments and crude oils
[Canning Basin, Western Australia and Western
Canada Sedimentary Basin (WCSB)]. A similar series
of low-molecular-weight A-norsteranes was also
generated from an extant sclerosponge by catalytic
hydropyrolysis (Hypy).
The samples from the Canning Basin are of Givetian
and Late Devonian age and were presumably
deposited in a shallow marine setting. The sediments
from the WCSB originate from the Frasnian Duverney
Formation which was mainly deposited in palaeowater
depths >100m. The dominant reef-building
organisms throughout the Devonian until the
Frasnian-Famennian mass extinction were
stromatoporoids. The oldest fossil remains of these
organisms date to the early Cambrian.
Stromataporoids were particularly abundant from the
Middle Ordovician to Late Devonian and from the
Jurassic to the Cretaceous [1]. It is now commonly
accepted that stromatoporoids are members of the
phylum porifera [1, 2]. Their closest living relatives are
presumably found amongst the sclerosponges since
both types of organisms show similar growth forms
and structural elements [1, 2]. Whereas various
studies have revealed a great diversity of sterol
structures within the class Demospongea [3], the
sterol compositions of sclerosponges have not been
robustly investigated. In this work we extracted a
sclerosponge collected from the Jamaican coast and
conducted Hypy on the residue. The pyrolysate was
further fractionated by silica gel column
chromatography. A series of C19 A-norsteranes was
tentatively identified in the Devonian stromatoporoidrich
sediments and crude oils as well as in the
aliphatic fraction of the pyrolysate of the extant
sclerosponge. We therefore propose that the putative
C19 A-norsteranes are novel biomarkers for
stromatoporoids and sclerosponges. This also
supports the theory of a close relationship between
extant sclerosponges and stromatoporoids. A
Precambrian oil from the South Oman Salt Basin [4]
was used as a reference to identify the putative Anorsteranes.
Furthermore, the polyaromatic hydrocarbon perylene
and aromatic compounds bearing the perylene
backbone - potential precursor fragments in the
sedimentary formation pathway to perylene - have
been detected in the Givetian sediments from the
Canning Basin. Perylene has been frequently
reported in Mesozoic and Cenozoic sediments, but it
has only occasionally been found in Paleozoic
samples [5]. Perylenequinone pigments present in a
variety of extant organisms including wood-degrading
fungi and crinoids have been suggested as potential
precursors on the basis of structural similarities [5, 6].
The sedimentary abundance of perylene has also
been linked with the activity of wood degrading fungi
[5]. Potential sources of perylene which might explain
its unusual appearance in these presumably marine
samples include perylenequinones in crionoids or
marine fungi. Furthermore, the perylene might
originate from terrestrial input and fungal lignin
degradation of early trees or from the organism
prototaxites, a giant terrestrial fungus abundant from
the Late Silurian until the Late Devonian.
In future studies we hope to examine the biomarker
composition – with special regard to the potential
novel sponge biomarkers - of additional samples from
the Canning Basin (Western Australia) to span the
Givetian-Frasnian boundary.
References
[1] Stearn, C.W., et al., Acta Palaeontologica
Polonica, 1999. 44(1): p. 1-70.
[2] Stearn, C.W., Lethaia, 1972. 5: p. 369-388.
[3] Bergquist, P.R., et al., Biochemical Systematics
and Ecology, 1991. 19(1): p. 17-24.
[4] Grosjean, E., et al., Organic Geochemistry, 2009.
40(1): p. 87-110.
[5] Grice, K., et al., Geochimica et Cosmochimica
Acta, 2009. 73(21): p. 6531-6543.
[6] Jiang, C., et al., Organic Geochemistry, 2000.
31(12): p. 1545.
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