From Reef Encounter 20, March 1997, page 14-15.
(Reef Encounter is the Newsletter of the International Society for Reef Studies)
The German Research Foundation 's Priority Programme entitled 'Global and Regional Controls of Biogenic Sedimentation - Reef Evolution and Cretaceous Sedimentation' held its closing colloquium at the University of Göttingen, 8-12 October 1996. The results of six years of joint reef research carried out under the umbrella programme were presented. There was also a poster session, review talks by invited speakers, an excursion to Permian reefs in Germany, and a presentation on the German International Year of the Reef Initiative (see p.xx).
The Priority Programme comprised a Reef Group and a Cretceous Group, which worked together collaboratively. The Reef Group, coordinated by Erik Flügel, concentrated on the biogenic and abiogenic factors controlling modern and ancient reef growth. The results from the work of this group were presented at the colloquium in several process oriented thematic talks, going beyond the confines of individual projects. Over the last six years the reef programme has focused mainly on the following:
1. Interdisciplinary research by biologists, geologists, paleontologists, bio/geochemists and oceanographers on factors controlling Holocene reef growth and carbonate production. Key targets were quantiutive assessments of growth rates and bioerosion, carbonate budgets, the role of nutrients in productivity, the influence of non-preservable or under-studied organisms on reef growth (e.g. soft corals, grazing fishes, bryozoans), microbial control of reef growth (calcification of biofilms, automicrite formation), microborers, ocean water chemistry, sea-level control, and comparisons with temperate and polar carbonate factories.
2. The use of these modern reef examples and controlling processes as partial keys to the past, for example the use of microborers as paleobathymetric indicators, environmental demands of modern siliceous sponges as a model for Ancient counterparts, biofilm calcification and automicrite formation in fossil mudmounds, soda lake chemistry as a partial analogue for Ancient oceans, distribution of Ancient cold water carbonates as mirrors for paleocurrent systems.
3. Anactualistic reefs: it became even more obvious during the Priority Program that many Ancient reef examples do not have modern counterparts. This holds true not only for sponge mudmounds, rudist or richthofenid reefs, but also for many types of microbolite reefs and even coral reefs, which include a great variety of subtypes. The analysis of the controlling mechanisms of these reefs was consequently based on a comparative analysis of reef associations, functional morphology of reef organisms, embedding of reefs in their structural, sedimentological, paleoceanographic and paleoclimatic framework, and control of reef occurrence, composition and distribution through sea level fluctuations. Fossil reefs (in the broad sense) that were studied spanned the Devonian to the Pleistocene. Most work groups focused on reefs and carbonate platforms from the Devonian (mounds and stromatoporoid reefs from central Europe, stromatolite reefs from Australia), Permian (differentiation of youngest Capitan reef types, Oman and northern Africa sponge and coral reefs, German stromatolite reefs, Richthofenia reefs for the first time studied in detail), Triassic (Alpine, Oman, Iran; evolution of Triassic reefs through time), Jurassic (all major occurrences, particularly on the Northern Tethys seas and in the Lusitanian Basin: comparative ecology of coral, siliceous sponge and microbolite reef) and Cretaceous (rudist reefs from Europe and Oman, comparison with coral reefs, development of the coral-coralline-reef type). Comparative analysis of mudmounds through time was another key topic, and this revealed the imporunce of ultraconservative microbial-sponge associations for the growth of this type.
4. Reefs as paleomonitors: Once studied in detail and calibrated with the regional setting, fossil reefs often turn out to represent good paleo-indicators for Ancient shelf structure, climate, current and nutrient systems, and sea level development (e.g. the Triassic, Jurassic and Cretaceous examples). This approach was accompanied and refined by reef modelling, the production of global paleoreef maps, and the analysis of differences and similarities with modern examples from comparable environmental and structural settings. Some of the results from the fossil examples might even allow a better understanding of modern reef growth (e.g. structural control of reef growth, importance of microbial activity for reef growth, temporal dynamics of reefs).
5. Reefs through time: In order to better understand the evolution of reefs through time, focus was put on the Frasnian-Fammenian, Permian/Triassic and Cretaceous/ Tertiary boundaries as well as on more continuous temporal changes in faunal composition, frequency and distribution from Triassic to Cretaceous reefs.
The success of the programme was largely due to its interdisciplinary approach, its strong focus on both biological paleontological and geological dau, and to the comparative analyses of
In a final discussion on future research needs, the following topics emerged:
A report has been published containing 65 overview papers by 118 authors and a bibliography of all published Priority Programme papers: Global and Regional Controls on Biogenic Sedimentation. 1. Reef Evolution (ed. by Reitner, J., Neuweiler, F & Gunkel, F). - Göttinger Arbeiten zur Geologie und Paläontologie, Sb 2, 428 pp, Göttingen (ISSN 0534-0403).
Available from: Institut und Museum für Geologie und Paläontologie (c/o Fritz Neuweiler), Universität Göttingen, Goldschmidt-Str. 3, D-37077 Göttingen, Germany.
Other results will be published in a book on the Evolution of Reefs being prepared by the reef group as well as in forthcoming papers.
Further information from: Reinhold Leinfelder, Institut für Geologie und Paläontologie, Universität Stuttgart Herdweg 51, D 70174 Stuttgart. Fax +49-71 1-121 1341, e-mail: r.leinfelder@lrz.uni-muenchen.de
or from Erik Flügel, Institut fiur Paläontologie, Universität Erlangen-Nümberg, Loewenichstr. 28 D-91054 Erlangen, Germany, Fax +49-9131-852690
Reefgroup Stuttgart (modern and Ancient Reefs): hnp://www.uni-stuttgart.de/UNluser/igps/reefgroup
Jurassic Reef Park: educational article giving an overview of modern reefs and reef organisms and comparison with fossil examples: http://www.uni-stuttgart.de/UNluser/igps/Jurassic_Reef_Park
This can also be accessed through the reef group pages.
Institut für Paläontologie, Erlangen: http://xray.geol.uni-erlangen.de/pal
Article submitted by Reinhold Leinfelder and Eric Flügel, edited by Sue Wells.
copyright Reef Encounter (ed. Sue Wells). IYOR-Germany thanks Sue Wells for permission to include this article to the Webpages of IYOR-Germany.
html-code: Reinhold Leinfelder, 2. May 1997
See also report on international IYOR activities, with special focus on Germany, from the same Reef Encounter issue.
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