Deep Earth Sampling Working Group Update 2007
(May 2007)
Benoit Ildefonse (CNRS/ISTEEM)
Working group members:
Wolfgang BACH - Bremen University, Bremen, Germany
Mathilde CANNAT - CNRS, Paris, France
Henry J.B. DICK - WHOI, Woods Hole, USA
Katrina EDWARDS - University of Southern California, USA
Kathryn GILLIS - University of Victoria, Victoria, Canada
Benoît ILDEFONSE (chair) - CNRS, Montpellier, France
Peter B. KELEMEN - Columbia University, Palisades, USA
Christopher J. MACLEOD - Cardiff University, Cardiff, UK
Jay MILLER - IODP-TAMU, College Station, USA
Yasuhiko OHARA - HODJ, Tokyo, Japan
Jan M. PETER - GSC, Canada
Damon TEAGLE - SOC, Southampton, UK
Douglas R. TOOMEY - University of Oregon, Eugene, USA
Susumu UMINO - University of Shizuoka, Shizuoka, Japan
Associated Scientists :
Natsue ABE - JAMSTEC, Yokosuka, Japan
Donna BLACKMAN - SCRIPPS, San Diego, USA
John CHEN - Beijing University, Beijing, China
David CHRISTIE - UFA, Fairbanks, USA
Nadine LE BRIS - Ifremer, Brest, France
Jim NATLAND - University of Miami, RSMAS, Miami, USA
Kyoko OKINO - ORI, Tokyo, Japan
Mission Moho:
Over the last year, most of the WG members were involved at various degrees with the "Mission Moho" project (missionmoho.org). This IODP mission proposal is an outcome of an international workshop, co-funded by IODP, JOI, Ridge 2000 and InterRidge, and co-chaired by B. Ildefonse and D. Christie, held in Portland, Oregon, on September 7-9, 2006. It has been submitted to IODP in April 2007. Mission Moho is an integrated campaign to understand the formation of the oceanic lithosphere with the ultimate goal of drilling a complete section through intact ocean crust, across the Moho and into peridotites of the upper mantle. It is the culmination of a four-decade quest by IODP and its predecessors (ODP, DSDP) to increase our understanding of the oceanic lithosphere through deep scientific drilling.
Active IODP proposals designed to drill at or close to mid-ocean ridges:
522-Full5 - D.A.H. Teagle - Superfast Spreading Crust - OTF
532-Full - B.E. Tucholke - Kane Megamullion - SSEP
535-Full5 - H.J.B. Dick - 735B Deep - SSEP
545-Full3 - A.T. Fisher - Juan de Fuca Flank Hydrogeology - OTF
547-Full4 - M. Fisk - Oceanic Subsurface Biosphere - SPC
551-Full - K.M. Gillis - Hess deep Plutonic Crust - SPC
584-Full2 - P.A. Rona - TAG II Hydrothermal System - SPC
640-Pre - Y. Ohara - Godzilla Mullion - SSEP
646-Full - B.J. Murton - Iceland Hotspot - SSEP
655-Pre - E.E. Davis - Juan de Fuca Observatories - SSEP
677-Full - K. Edwards - Mid-Atlantic Ridge Microbiology - OTF
719-MP - B. Ildefonse - Mission Moho - SSEP
Full: full proposal; Pre: pre-proposal; MP: Mission proposal
OTF: Operations Task Force (logistics being planned; expedition not yet scheduled)
SPC: Science Planning Committee (project is being ranked relative to other proposals)
SSEP: Science Steering & Evaluation Panel (under review or prior panel advise is being incorporated before revised version submitted)
Recent, forthcoming or proposed survey and test activities:
1) Test of a new 15m seabed rock drill.
The British Geological Survey spent 6 days testing "RD2", a new seabed rockdrill that allows drilling 15m long cores, in the hydrothermal areas of the Mid-Atlantic Ridge at ~15°N (water depths from 2980m to 3050 m).
Read the news item in : http://www.intoceansys.co.uk/cgi-bin/news.cgi?section=news.
2) Serpentinite-rich seafloor at the Mid-Atlantic Ridge
The beginning of 2007 was very active on the front of surveying serpentinite-rich seaflloor areas and related hydrothermal sites, with the french cruise "Serpentine" (http://www.ifremer.fr/serpentine/) and the british cruise "JC07" (http://www.noc.soton.ac.uk/gg/classroom@sea/JC007/). The effort continues this summer 2007 (June-July), with the MOMAR-DREAM Cruise (RV/Pourquoi Pas ?, ROV surveying and sampling), in the area of the serpentinite-hosted Rainbow hydrothermal field at 36°N.
3) Godzilla Mullion site survey, R/V Hakuho, Aug-Sep 2007.
Basic site survey at Godzilla Mullion (IODP pre-proposal 640-Pre) has already been completed (full-cover bathymetry, MCS, seismic refraction study using OBSs). The main objective of this cruise (PI : Y. Ohara) is to increase the number of dredge sites to map lithological variations along this ~ 120 km-long oceanic core complex. 3.5 KHz sub-bottom profiling and deep-towed magnetometer survey will also be conducted.
4) Hess Deep (JC20). RRS James Cook, Jan-Feb 2008.
This NERC funded cruise (MacLeod and Teagle) will survey the Hess Deep area (ROV surveying + Seabed rock drilling) to further constrain the seafloor geology and the location of future drill sites (Proposal 551-Full).
5) Proposal for 3D seismic imaging of the Atlantis Massif (Mid-Atlantic Ridge, 30°N).
Following the IODP Expeditions 304-305, a proposal for further integrated geophysical experiments at the Atlantis Massif has been recently submitted to NSF (Blackman et al.). The main component of the project is a 3D seismic survey of the massif. The new seismic results is intended to provide a framework to integrate existing and future geological results at Altantis Massif, including further deep drilling in IODP Hole U1309D.
