Jurassic corals as emersion indicators
Version of Record online: 2 JAN 2007
Volume 33, Issue 4, pages 341–344, December 2000
How to Cite
Habrant, N. and Lathuilière, B. (2000), Jurassic corals as emersion indicators. Lethaia, 33: 341–344. doi: 10.1080/002411600750053907
- Issue online: 2 JAN 2007
- Version of Record online: 2 JAN 2007
- 9th February, 2000; revised 27th June, 2000.
- sea level
In Recent coral reefs, emersion has resulted in the development of special growth forms of colonial corals which have been named microatolls. These colonies grow almost exclusively in a horizontal direction. In the upper part of the colony, subaerial exposure leads to the decay of the living body. The growth then stops and the skeleton is later colonized by various boring and encrusting organisms. Here we show the first record of a massive Mesozoic coral colony displaying the main features of emersion. The colony has been collected in perireefal Oxfordian (Jurassic) limestones from the Jura Mountains (France). It is situated exactly at the expected place in a shallowing-upward sequence between infralittoral buildups and supralittoral limestones. We suggest that such growth structures could be more common than previously thought in ancient coralliferous sediments and add some new details to discriminate between these colonies.