Frontispiece. A. Leg 179 operations area within the Indian Ocean, which included the Atlantis Bank along the Atlantis II Transform for hammer drilling (Sites 1104 and 1106) and contingency coring of gabbroic rocks (Site 1105) and the Ninetyeast Ridge (Site 1107) for the geophysical ocean-bottom observatory site. B. A QuickTime movie of the bathymetry of the Atlantis II Transform, which offsets the Southwest Indian Ridge (SWIR), showing the position of the Atlantis Bank. C. Close-up of the Atlantis Bank where gabbroic rocks were drilled using the hammer drill and the standard rotary core barrel drilling systems. D. Schematic view of the hammer drill-in casing system that was tested. E. Percussion bit deployed with the hammer drill-in casing system at Sites 1104 and 1106. F. Fully assembled SDS hammer drill-in casing system on the rig floor of the JOIDES Resolution. G. Schematic columns showing the differences between the ophiolite model of oceanic crust and upper mantle, identifying typical major lithologic units, vs. a geophysical model of slow-spreading oceanic crust, which predicts only small ephemeral magma chambers. These models will be tested with results of the sampling of the plutonic foundations of the oceanic crust from the contingency Hole 1105A. H. Igneous textured olivine gabbro from Hole 1105A. I. Highly deformed porphyroclastic mylonite textured metagabbro from Hole 1105A. J. Formation MicroScanner imaging of layered gabbroic rocks with lithologic and structural correlations in the core from Hole 1105A. K. Schematic diagram showing the geometry and structure of Site 1107 ready for deployment of a geophysical ocean-bottom observatory at the Ninetyeast Ridge.

Proceedings of the
Ocean Drilling Program

Volume 179
Initial Reports
Hammer Drilling and NERO

Covering Leg 179 of the cruises of the Drilling Vessel JOIDES Resolution
Atlantis Bank, Southwest Indian Ridge
Sites 1104–1107
9 April–7 June 1998

SHIPBOARD ENGINEERS/SCIENTISTS
Thomas J. Pettigrew, John F. Casey, D. Jay Miller,
Eiichiro Araki, Remi Boissonnas, Robert Busby, Florence Einaudi, Martin Gerdom, Zhong Ping Guo, Hartley Hoskins, Greg Myers, Dasari Gopala Rao, Tsugio Shibata, Peter Thy

SHIPBOARD STAFF SCIENTIST
D. Jay Miller

VOLUME EDITOR
John M. Scroggs

Citation

Reference to the whole or to part of this volume should be made as follows:

WWW volume citation:
Pettigrew, T.L., Casey, J.F., Miller, D.J., et al., 1999. Proc. ODP, Init. Repts., 179 [Online]. Available from World Wide Web: <http://www-odp.tamu.edu/publications/179_IR/179TOC.HTM>. [Cited YYYY-MM-DD]

WWW chapter citation (PDF):
Shipboard Scientific Party, 1999. Hammer Drill Site (1104 and 1106) and Site 1105. In Pettigrew, T.L., Casey, J.F., Miller, D.J., et al., Proc. ODP, Init. Repts., 179, 1-183 [Online].  Available from World Wide Web: <http://www-odp.tamu.edu/publications/179_IR/VOLUME/CHAPTERS/CHAP_04.PDF>. [Cited YYYY-MM-DD]

WWW chapter citation (HTML):
Shipboard Scientific Party, 1999. Hammer Drill Site (1104 and 1106) and Site 1105. In Pettigrew, T.L., Casey, J.F., Miller, D.J., et al., Proc. ODP, Init. Repts., 179 [Online].  Available from World Wide Web:
<http://www-odp.tamu.edu/publications/179_IR/chap_04/chap_04.htm>. [Cited YYYY-MM-DD]

Printed booklet citation for Chapter 1:

Shipboard Scientific Party, 1999. Leg 179 Summary. In Pettigrew, T.L., Casey, J.F., Miller, D.J., et al., Proc. ODP, Init. Repts., 179: College Station, TX (Ocean Drilling Program), 1–26.

CD-ROM volume citation:
Pettigrew, T.L., Casey, J.F., Miller, D.J., et al., Proc. ODP, Init. Repts., 179 [CD-ROM]. Available from: Ocean Drilling Program, Texas A&M University, College Station, TX 77845-9547, U.S.A.

CD-ROM chapter citation:
Shipboard Scientific Party, 1999. Hammer Drill Site (1104 and 1106) and Site 1105. In Pettigrew, T.L., Casey, J.F., Miller, D.J., et al., Proc. ODP, Init. Repts., 179, 1–183 [CD-ROM]. Available from: Ocean Drilling Program, Texas A&M University, College Station, TX 77845-9547, U.S.A.

ISSN
Printed booklet: 0884-5883; CD-ROM volume: 1096-2522; WWW volume: 1096-2158
Library of Congress 87-642-462

Effective publication dates of ODP Proceedings

According to the International Code of Zoological Nomenclature, the date of publication of a work and of a contained name or statement affecting nomenclature is the date on which the publication was mailed to subscribers, placed on sale, or when the whole edition is distributed free of charge, mailed to institutions and individuals to whom free copies are distributed. The mailing date, not the printing date, is the correct one.

The printing date of this volume: July 1999

The mailing dates of recent Proceedings of the Ocean Drilling Program:
Volume 175 (Initial Reports): November 1998
Volume 176 (Initial Reports): June 1999
Volume 177 (Initial Reports): May 1999
Volumes 159/159T (Scientific Results): October 1998
Volume 160 (Scientific Results): September 1998
Volume 161 (Scientific Results): February 1999

Copies of this publication may be obtained from Publications Distribution Center, Ocean Drilling Program, Texas A&M University, 1000 Discovery Drive, College Station, TX 77845-9547, U.S.A. See the ODP publication list at www-odp.tamu.edu/publications or contact ODP for prices and ordering information. Orders for copies require advance payment.

Publisher’s Notes

This publication was prepared by the Ocean Drilling Program, Texas A&M University, as an account of work performed under the international Ocean Drilling Program, which is managed by Joint Oceanographic Institutions, Inc., under contract with the National Science Foundation. Funding for the program was provided by the following agencies at the time of this cruise:

Australia/Canada/Chinese Taipei/Korea Consortium for Ocean Drilling: Department of Primary Industries and Energy (Australia), Natural Resources Canada (Canada), National Taiwan University in Taipei, and Korean Institute for Geology, Mining and Minerals

Deutsche Forschungsgemeinschaft (Federal Republic of Germany)

European Science Foundation Consortium for Ocean Drilling (Belgium, Denmark, Finland, Iceland, Italy, The Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, and Turkey)

Institut Français de Recherche pour l’Exploitation de la Mer (France)

National Science Foundation (United States)

Natural Environment Research Council (United Kingdom)

University of Tokyo, Ocean Research Institute (Japan)

Any opinions, findings, and conclusions or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the National Science Foundation, the participating agencies, Joint Oceanographic Institutions, Inc., Texas A&M University, or Texas A&M Research Foundation.

Abbreviations for names of organizations and publications in ODP reference lists follow the style given in Chemical Abstracts Service Source Index (published by American Chemical Society).

The bulk of the shipboard-collected data from this leg is available on the World Wide Web and is accessible at www-odp.tamu.edu/database. If you cannot access this site or need additional data, please contact the ODP Data Librarian, Ocean Drilling Program, Texas A&M University, College Station, TX 77845-9547, U.S.A. (e-mail: database@odpemail.tamu.edu).

Supplemental data on the volume CD-ROM were provided by the authors and may not conform to ODP publication formats.

A site map showing the drilling locations for this leg and maps showing the drilling locations of all Ocean Drilling Program (ODP) and Deep Sea Drilling Project (DSDP) drilling sites are available on the volume CD in PDF format.

Beginning with Initial Reports Volume 176 and Scientific Results Volume 169, all Proceedings volumes will be published on CD-ROM and the World Wide Web at www-odp.tamu.edu/publications.

Initial Reports Scientific Results
Booklet format: ISSN 0884-5883 Book: ISSN 0884-5891
CD-ROM format: ISSN 1096-2522 CD-ROM format: ISSN 1096-2514
WWW format: ISSN 1096-2158 WWW format: ISSN 1096-7451

Cover photograph of the hammer drill and Chief Engineer Tom Pettigrew by ODP Photographer Roy Davis.

Foreword

By Joint Oceanographic Institutions, Inc.

This volume presents scientific and engineering results from the Ocean Drilling Program (ODP). These results address the scientific and technical goals of the program, which are focused on the study of the dynamics of Earth’s interior and environment.

ODP, an international partnership of scientists and research institutions from 22 countries, operates the drillship JOIDES Resolution. This state-of-the-art research vessel contains seven levels of laboratories and other scientific facilities required for carrying out the program’s objectives.

The management of ODP involves a partnership of scientists and governments. International oversight and coordination are provided by the ODP Council, which is made up of representatives from the member countries. Overall scientific and management guidance is provided by representatives from the Joint Oceanographic Institutions for Deep Earth Sampling (JOIDES).

Joint Oceanographic Institutions, Inc. (JOI), a nonprofit consortium of eleven U.S. oceanographic institutions, serves as the National Science Foundation’s prime contractor for ODP. JOI implements scientific objectives, plans, and recommendations of the JOIDES committees through major subcontracts to Texas A&M University (TAMU) for science operations and to Lamont-Doherty Earth Observatory (LDEO) of Columbia University for logging services.

JOI, TAMU, and LDEO have worked together successfully for many years to manage the Ocean Drilling Program. We look forward to many exciting discoveries and continued international collaboration as we further our scientific mission, especially the planning for the future of ocean drilling beyond 2003.

James D. Watkins
Admiral, U.S. Navy (Retired)
President, Joint Oceanographic Institutions, Inc., Washington, D.C.

Ocean Drilling Program*

*At time of publication. See Publisher’s Notes, for list of funding agencies at time of cruise. For an up-to-date list of current member organizations and office contact information, see the ODP Web site: www.oceandrilling.org.

National Science Foundation
4201 Wilson Boulevard
Arlington, VA 22230, U.S.A.
Tel: (703) 306-1581; Fax: (703) 306-0390
Web site: www.nsf.gov

Member Organizations of the Joint Oceanographic Institutions for Deep Earth Sampling (JOIDES)

University of California at San Diego, Scripps Institution of Oceanography

Columbia University, Lamont-Doherty Earth Observatory

University of Hawaii, School of Ocean and Earth Science and Technology

University of Miami, Rosenstiel School of Marine and Atmospheric Science

Oregon State University, College of Oceanic and Atmospheric Sciences

University of Rhode Island, Graduate School of Oceanography

Rutgers, The State University of New Jersey, Institute of Marine and Coastal Sciences

Texas A&M University, College of Geosciences

University of Texas at Austin, Institute for Geophysics

University of Washington, College of Ocean and Fishery Sciences

Woods Hole Oceanographic Institution

Australia/Canada/Chinese Taipei/Korea Consortium for Ocean Drilling: Department of Primary Industries and Energy (Australia), Department of Energy, Mines and Resources (Canada), National Taiwan University in Taipei, and Korean Institute for Geology, Mining and Minerals

European Science Foundation Consortium for Ocean Drilling (Belgium, Denmark, Finland, Iceland, Italy, The Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, and Turkey)

Federal Republic of Germany, Bundesanstalt für Geowissenschaften und Rohstoffe

France, Institut Français de Recherche pour l’Exploitation de la Mer

Japan, University of Tokyo, Ocean Research Institute

People’s Republic of China, Marine High-Technology Bureau of the State Science and Technology Commission of the People’s Republic of China

United Kingdom, Natural Environment Research Council

Ocean Drilling Program (ODP)
Web site: www.oceandrilling.org

Leg 179 Participants*

*Mailing addresses at time of cruise. Addresses may be updated. Send requests to pub_production@odpemail.tamu.edu.

Shipboard Scientific Party

 **Personnel roster corrected September 2001.

ODP Publications Staff^*

*At time of publication.
†Lead staff members for this volume.

Acknowledgments

The Leg 179 Shipboard Scientific Party thanks Captain Tom Ribbens and the officers and crew of the JOIDES Resolution. We also thank the Ocean Drilling Program (ODP) staff who helped make it possible for the rather small shipboard scientific party to respond to a very successful contingency Hole 1105A drilled along the Atlantis II Transform. We recovered far more gabbroic material than anticipated in the prospectus. The staff provided the support necessary to describe, analyze, and sample 143 m of gabbroic core drilled in six days. Put into perspective, this recovery exceeded the total recovery of gabbro during Legs 147 and 153, which were devoted to drilling the plutonic foundations of the oceanic crust. We also thank Schlumberger Engineer Steve Kittredge and the Lamont-Doherty Earth Observatory Logging Services staff members, who expertly and thoughtfully logged Hole 1105A and provided us with the first high-quality Formation MicroScanner images of a hole drilled into oceanic gabbros.

We also greatly appreciated the efforts of Dr. Henry Dick and the captain, staff, and crew of the James Clark Ross, who effected a transfer of site survey bathymetry and sample location data at sea. This data collected over the Atlantis Bank allowed us to select the unanticipated contingency Site 1105. Dr. Dick has also been a tireless champion of drilling along the Southwest Indian Ridge and largely provided the background data necessary for selection of the hammer test site.

We express our gratitude to those who helped us on the rig floor to conduct the first tests of the hammer drill and complete the leg's primary objectives, literally in the nick of time. The entire Sedco crew was very helpful and instrumental in accomplishing the difficult task of testing the hammer drill. Invaluable input was provided by Rig Superintendent Bob Caldow, Tool Pusher Scott Pederson, and Core Technicians Bill Lee and Tim McCown. We would also like to thank SDS Digger Tools, Ltd., for providing the water hammers and bits. Special thanks go to SDS Engineers Taras Olijnyk and Paul Speight and ODP Special Tools Engineer Leon Holloway, who spent long hours on the rig floor looking after the hammers and coaching the drillers on hammer drill operational techniques. The entire rig floor crew expertly adapted to the hammer drill tests, suffered through intense vibrations on the rig floor during the hammer drilling, and drilled with magnificent efficiency to complete Hole 1105A on the Atlantis Bank and Hole 1107A on the Ninetyeast Ridge in difficult sea states. Together with Drill Pipe Operator John Powell, they also expertly reentered hard-rock Hole 1105A under both difficult sea-state and bottom conditions. This ultimately allowed us to deepen the hole significantly. Lastly, their diligent efforts and expertise are largely responsible for successfully completing the Ninetyeast Ridge Observatory (NERO) hole just before the scheduled departure time. The hole will house the first downhole geophysical observatory in a remote part of the Indian Plate and should fill one of six major gaps in worldwide seismic coverage. We also thank Drs. John Orcutt, Jean-Paul Montagner, and Susan Humphris for their helpful comments during the leg regarding requirements for the NERO Hole.

We thank the Sedco crew members for their long and tireless efforts in repairing the JOIDES Resolution's guidehorn, damaged during a previous leg, without which we would have been more seriously delayed in Capetown. We likewise thank the captain, crew, and ODP staff for their perseverance on a cruise made difficult because of delays in leaving port, errant supply shipments, long transits, and nearly continuous high sea states throughout the leg. They willingly responded in a positive way to a two-day leg extension resulting from these difficulties. This extension caused considerable inconvenience for many on the leg who had to rearrange previous commitments. Even with the extension, the significant amount of time lost during the leg resulted in cancellation of certain ancillary programs. The most difficult and complex of these was a proposed two-ship seismic experiment with the German research vessel Sonne, which was involved in seismic experiments near the NERO Site. Although scheduled for the last two days at the NERO site, the experiments would have interfered with the primary objective of completing the NERO hole, which was completed only hours before our scheduled departure. We particularly thank Dr. Ernst Fleuh and the scientific staff of the Sonne, as well as others whose experiments were affected, for their understanding of the unanticipated logistical and operational difficulties incurred during the leg.

Finally, we wish to thank the ODP Publication Services staff members, who helped us to complete this volume and present World Wide Web-based data in a more innovative manner.