Bali Workshop Announcement
blanchon at mar.icmyl.unam.mx
Mon Sep 25 14:31:28 EDT 2000
Invitation to attend and participate in:
A Virtual Reef-Core Workshop
9th International Coral Reef Symposium, Bali, Indonesia 23-27 Oct 2000
Evening of Tues 24th. Room TBA
Convenor: Paul Blanchon, UNAM.
Over the last decade the use of coral-reef sequences to study climate
variability during the Quaternary has increased significantly. In
some classic areas, like Barbados and the Huon Peninsula, rapid
neotectonic uplift has elevated reef sequences and allowed important
discoveries to be made about the link between the Earth's orbital
parameters and the timing of climate oscillations. But the very
process that makes these records accessible--uplift--also creates
uncertainty in determining the rate and magnitude of such changes,
especially in the case of sea level. As a consequence, many
investigators interested in climate change have now started to
examine reef sequences in more stable areas that are below sea-level.
The recovery of these submerged records commonly requires a major
drilling operation because alternations of coral, rubble and sand can
make downhole conditions difficult for portable rigs which can only
handle short, small-diameter cores. The problem with large rigs,
however, is that they restrict operations to accessible areas on the
reef crest, which makes it difficult to recover of a complete record
when a reef has undergone retro- or progradation during its
development. Once a complete record is recovered, however, the next
problem is obtaining an accurate description and interpretation of
the complex textures and fabrics found in reef facies. This
complexity can be severe. Even in outcrop, coral reef sequences are
an intricate mosaic of corals and sediment that have been encrusted
and bioeroded: they commonly bear little resemblance to the surface
zonations we find covering modern reefs. In core, such complexities
are magnified ten-fold and even distinguishing in-place coral from
biodetritus can be impossible in some cases.
This Virtual Reef-Core Workshop is a forum in which to discuss not
only new and improved drilling methods but also how to improve the
scientific description and analysis of reef deposits from core data.
Participants will be asked to bring high-resolution, full size images
of reef cores that have been assembled so as to represent a 'virtual'
core. (A good way to do this is to scan sliced pieces of core into an
illustration program and print on a photo-quality printer. Each core
section can then be taped together and fan-folded). By collectively
examining these virtual reef cores, we hope to:
1) familiarize ourselves with the often complex fabrics and textures
of reef facies and see how they compare/contrast with the modern
2) incite some constructive discussion on how to schematically
represent the biosedimentology of the cores in an efficient and
3) establish some possible ways of identifying (and even quantifying)
in-place framework from biodetrital deposits.
At regular intervals during the workshop, we will try to arrange
brief presentations on specific drilling methodologies, hopefully
including advances in technology and techniques.
Contributions to date
Dennis Hubbard (Oberlin College). Virtual Core from St. Croix
and/or Puerto Rico
Dennis Hubbard. Video/slide show on the SCARID underwater drilling system
Paul Blanchon (National Autonomous U. Mexico). Short cores from the
crest of an early Holocene relict reef discovered recently off the
east coast of Grand Cayman.
Paul Blanchon. Informal poster on classification of reef deposits.
Zelinda Leão (U. Federal da Bahia). Core from a reef flat in the
Abrolhos Region, Eastern Brazil (southernmost coral reefs in Western
Atlantic). Core is ~13 meters long and reaches Pleistocene basement.
This reef is surrounded by siliciclastic sediments and its major
reef-building corals are endemic forms from Brazil.
Keiichi Sasaki (Kanazawa U.). Cores from Kikai Island Reefs, Ryukyus.
Ian Macintyre (Smithsonian). Cores that show development of
pavement limestone. It forms when there is a hiatus in reef accretion
and is due to multicyclic boring and inflilling which tend to destroy
all evidence of the original skeletal framework.
David Blakeway (U. Western Australia). Core from Ningaloo Reef.
David Kennedy (U. Wollongong). Virtual cores from Middleton Reef,
Elizabeth Reef and fringing reefs in the Torres Strait.
Further contributions are welcome: for details email me at
blanchon at icmyl.unam.mx
Dr. Paul Blanchon | Investigador
Coral-Reef Systems Lab.
Unidad Academica Pto. Morelos
Inst. de Ciencias del Mar y Limnologia (ICML)
Universidad Nacional Autonoma de Mexico (UNAM)
Ap. Postal 1152, CP 77500 Cancún,
Q. Roo, MEXICO
Tel. (987) 10219, Fax: (987) 10138
Work E-mail: blanchon at icmyl.unam.mx
Home E-mail: blanchon_s at hotmail.com
National Autonomous University of Mexico, 1553-2000
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the Coral-list-old