TheIA VCEI (International Association of Volcanology and Chemistry of the Earth's Interior)Commission on Large-Volume Basaltic Provinces

Number4

November 1994

Flows on Venus are highlighted in this issue, as are future plans for ·scientific ocean drilling of large igneous provinces (LIPs). A formal link
between our Commission and the Ocean Drilling Program (ODP) has been
established; we have been invited to provide scientific input to ODP. Plans
for the volume on LIPs are well developed, and all members should plan toattend our Commission's first symposium and field excursion(s) at the
1995 IUGG XXI General Assemqly in Boulder, Colorado. The Steering
Committee is nearing full quota and is actively guiding the Commission's
activities; please contact any of the members listed below for suggestions,contributions, comments, etc. As usual, we welcome your ideas, your input
to The LIP Reader, and your recruiting of interested scientists to join theCommission.

Commission News

LeaderMike Coffin
Institute for Geophysics
The University of Texas at Austin
8701 North Mopac Expressway
Austin, TX 78759-8397, USA.
Tel: 1.512.471.0429
fax: 1.512.471.8844
internet:mikec@coffin.ig.utexas.edu
Secretary
John Mahoney
Department of
Geology and Geophysics
School of Ocean and Earth Scienceand Technology
University of Hawaii
2525 Correa Rd.
Honolulu, HI 96822, USA.
Tel: 1.808.956.8705
fax: 1.808.956.2538
internet:
jmahoney@soest.hawaii.edu
Newsletter Production
Judith Haller and Toni Lee Mitchell

Steering Committee
Members of the Steering Committee include:
Hans Barsczus (Univ. of Montpellier, France)-barsczus@sajou.dstu.univmontp2.fr
Ian Campbell (Australian National Univ., Australia)ihc 1561@huxley.anu.edu.au
Mike Coffin (Univ. of Texas, USA)-mikec@coffin.ig.utexas.edu
Keith Cox (University of Oxford, UK)-trishm@earth.ox.ac.uk
Geoff Davies (Australian National Univ., Australia)-geoff@rses.anu.edu.au
Jean Goslin (Univ. of Brest, France)-goslin@univ-brest.fr
Chris Harris (Univ. of Cape Town, South Africa)-kv@geology.uct.ac.za
Chris Hawkesworth (Open Univ., UK)-j.l.dryden@open.ac.uk
Jim Head (Brown Univ., USA)-head@pggipl.geo.brown.edu
Jan Hertogen (University of Leuven, Belgium)-fgeea03@ccl.kuleuven.ac.beJohn Mahoney (Univ. of Hawaii, USA)-jmahoney@soest.hawaii.edu
Sverre Planke (Univ. of Oslo, Norway)-sverre.planke@geologi.uio.no
Jakob Skogseid (Univ. of Oslo, Norway)-jakob.skogseid@geologi.uio.no
Kensaku Tamaki (Univ. of Tokyo, Japan)-tamaki@ori.u-tokyo.ac.jp
Dominique Weis (Free Univ. of Brussels, Belgium)-dweis@resulb.ulb.ac.be
Dave Williams (Univ. of Alabama, USA)-dwillia3@ualix.ua.edu
Full addresses and contact numbers for the above are available over theinternet, on diskette, or as hard copy (see below) from Mike Coffin.

Volume on Large Igneous Provinces
The volume on Large Igneous Provinces iscoalescing. To date, reviews of the following
topics have been proposed Oead authors only arelisted): Ferrar Group (D. Elliot); Indochina/S
China Sea Neogene-Quaternary volcanism (M.
Flower); Columbia River (P. Hooper); Rajmahal
Traps and Cretaceous oceanic plateaus in theeastern Indian Ocean (R. Kent); CaribbeanColombian province (A. Kerr); North American
accreted terranes, including Wrangellia a.
Lassiter); Middle Jurassic silicic province ofPatagonia and Antarctica (P. Leat); Ontong Java
Plateau a. Mahoney); Karoo (G. Marsh); ParanaEtendeka (D. Peate); North Atlantic TertiaryIcelandic plume UP (A. Saunders); Emplacement
mechanisms of flood basalt lavas (S. Self); Madagascar province (M. Storey). Negotiations withprospective publishers are underway. Stilllacking are pledged manuscripts on several
major LIPs (e.g., Siberian, Ethiopian, and Deccan
Traps); potential authors are invited to contact
John Mahoney.
Field Excursions/Workshops/Short Courses/
Special Meetings
The 1995 IUGG XXI General Assembly in Boulder,
Colorado (see "Meetings Schedule" below), hasbeen targeted for the Commission's first field
excursion(s). Possibilities being investigated by
Nick Arndt and John Ludden include the Columbia River basalts, Wrangellia, and Yellowstone.
Please contact any member of the Steering
Committee if you would like to run or helporganize a special field excursion, workshop,
short course, or meeting relevant to LIPs.

Recent Research Summary
Large-Scale Flow Fields on Venus: Comparisons

to Terrestrial Flood Basalts

A population of 208 large flow fields (areas>-50,000 km2, average -220,000 km2, maximum-1.6 x 106 km2) has been identified on Venus
from the global Magellan radar image data. The
population covers a total area of -4.0 x 107 km2,
9% of the surface area of this Earth-sized planet.
Sources for the majority of these flow fields arecoronae (features thought to be the surface
manifestations of mantle upwellings impinging
against the lithosphere), volcanic shields, andfractures or fissures within rifts and fracture
belts. Most flow fields are located within zones
of extension; emplacement largely post-dates theonset of extension. Controversy regarding theformation of flood basalts on Earth centers on
the relative importance of large-scale mantle
upwellings (or plume heads) and lithosphericextension to enhance decompression melting.
The association of large flow fields with rifts andfracture belts strongly indicates that lithosphericextension and thinning are necessary for theformation of most flood-scale lavas on Venus.
Association with large-scale mantle plumes isalso evident for the 15% of all flow fields ob-

served in clusters of coronae and volcanoes or in
the large regional rises of Venus. Thus, mantle
plumes may be linked to the origin of some of
the large flow fields on Venus, but are notnecessary for the formation of the vast majorityof such features. In addition to being strongly
associated with zones of extension, large flow
fields on Venus differ from terrestrial floodbasalts in their abundance (more numerous,
perhaps due to the slightly older average age ofVenus), and in their volumes (about an order ofmagnitude less than terrestrial flood basalts,
perhaps due to mantle temperature differences,
structure and duration of mantle anomalies).
Further interplanetary analysis of these characteristics can lead to a more complete understanding of LIPs in the geological record.
contributed by Kari Magee and Jim Head, Brown
University

Summaries of recent research programs areinvited-please send your contribution to Mike
Coffin or John Mahoney. For the sake of brevity,references are omitted; please contact thecontributors directly for more information.

Previous meetings
Mafic Magmatism through Time Workshop, St.
Malo, France, 9-13 May 1994.

~ LIPs were the subject of a lively session at this2

workshop. Close to 100 petrologists, geochemists, and geophysicists soon became accustomed
to good French food and wine, and to the splendid ocean views from the conference center, asthey settled down to compare and contrast
modern and ancient volcanism and to discuss
how any important differences may have arose.
The LIP session started with talks on oceanic
plateau s in the Pacific. The opening presentation, by M. Coffin, was a general overview of thep etrological and geophysical features of LIPs. He
reiterated his conclusions about the vast size ofthese mainly basaltic eruptions and his startlinginferen ces about the enormous volumes ofmantle involved in their formation. L. Kroenke
continued with a presentation of the geophysicaldata that constrain the relationship between theformation of plateaus and the distribution ofplates. He emphasized that "plumology" wasnot a unique interpretation and that a complex
interplay of triple junctions and plate motion
changes can also help account for the generationof plateau s. j . Mahoney continued with anaccount of the Ontong java Plateau, emphasizing
the geochemical and isotopic homogeneity of theprovince, the world's largest. In con trast, M.
Pringle discu ssed Cretaceous OIBs from a
relatively restricted area of the west Pacific(SOPITA) which exhibits evidence for just about
every postulated mantle reservoir. G. Marriner,
returning from las t winter's "field" season,emphasized the importance of picrites andkomatiites in the Caribbean plateau and theColumbian cordillera, where a section throughoceanic plateau crust reveals an abundance of
picrites in the lower levels. G. Fitton and A.
Saunders presented geochemical results fromnew ODP drill cores on the East Greenland rifted
margin, and F. Frey and D. Weis presented asynthesis of geochemical data from the Kerguelen volcanic province. A comment by G.
Czamanske introduced a discussion of continental flood basalts, but lack of time prevented afull discu ssion of these rocks. A presentation by
R. Kent of his inversion modeling of Kerguelenrelated Indian Ocean basalts provoked a spirited
attack by F. Albarede on the technique. D.
McKenzie had barely time to start his defense
before the session had to be closed for lunch.
LIPs also featured during the last two days of themeeting when experimental and chemical data
were presented and petrogenetic theory was
discussed. Notable interventions were K.
Gallagher's gallant defense of melting in a wet
lithosphere, and M. Cheadle and H. Iwamori's
modeling of melt generation and segregation inplumes.
Several important issues emerged from thediscussions:
The probability that many ancient greenstones
may be fragments of oceanic plateau s and theneed to better characterize modern LIPs in termsof volcanic morphology, sedimentology, struc-ture, and geochemistry. Early continental crust
may have been largely derived from accreted
plateaus, and originally mafic-ultramafic incomposition.
The nature of hydrothermal alteration in oceanic
plateaus, and whether the type of alteration
preserved in basalts of Archean greenstone belts
can help establish whether they formed at a midocean ridge or at a plateau.
The overall composition of oceanic and continental plateaus, and the nature of the primarymagmas. While it was recognized that the basalts
that constitute the bulk of such sequences had
undergone low-pressure fractional crystallization,
opinions differed on the extent of fractionationand the degree of interaction with lithosphericwall rocks. As anticipated, the thorny questionsof crustal contamination of flood basalts raised its
head, and as expected, the proponents of alternative interpretations repeated their arguments andstuck to their guns.
New and interesting data concerned the traceelement and isotopic compositions of the older
plateau basalts from Kerguelen. Weis, Frey, andMahoney confirmed results first presented at
lAVCEI Canberra which showed that certain
basalts in the older plateau sequences had negative Nb-Ta anomalies, high B7SrjB6Sr and low tNdvalues of the type normally associated with acontinental or island arc setting. Although an
attempt was m ade at the meeting to attributethese characteristics to the "lithosphere" (thecustomary repository of all unexplained chemicalsignatures), the question deserves more serious
discussion.
Our limited understanding of modern LIPs proveda handicap in understanding their evolution
through time. That LIPs may represent analogs ofancient greenstone belts in probable. Komatiite
magmas in the Caribbean province indicate thatthe ancient geological record can provide asimportant a constraint on the modern Earth asmodern volcanic environments provide in theancient record.
contributed by Nick Arndt and j ohn Ludden

The Icelandic Plume and its Influence on theOpening of the NE Atlantic, Reykjavik, Iceland, 48 july 1994.
The second Arthur Holmes European Research
Meeting was held at a time of heightened interestin the causes and effects of the Icelandic Plume.
The level of interest in the topic is manifested byseveral major ongoing geological initiatives,
including the Ocean Drilling Program (Leg 152
drilled Early Tertiary basalts on the East3

Greenland margin), the British Mid-Ocean Ridge
Programme (which includes the Reykjanes Ridgeas one of its key research areas) and imminent
geophysical experim ents (ICE and FIRE), which
will investigate the nature of the crust of Iceland
and adjacent areas. The meeting attracted agroup of some 50 geoscientists, including bothinternationally-respected authorities and postgraduate research s tudents. Delegates traveledfrom Britain, Ireland, Denmark, Norway, France,
Germany, and the USA, joining a major andinfluential group from the Icelandic geologicalcommunity. The presentations covered six main
themes: melt generation; the relative importanceof plume, MORB, and other magma sources;
breakup processes and effects on marginalbasins; timing and expression of volcanic and .
tectonic events; and geochemical and geophysicalmanifestations of the plume through time andspace. The location of the meeting in Reykjavik
was vital to the success of the meeting, allowing
the delegates to discuss these key topics withdirect references to the present-day effects of theplume, both through papers given during thetechnical sessions and during the conference field
trips.

Sessions were open to all disciplines to promote
cross-fertilization of ideas. Oral presentations
were relatively short (1 5 minutes) with 5 minutes
for questions and comments. Each presentation
was accompanied by a poster to promote further
discussion during the morning, lunch, andafternoon breaks. The result was a forum inwhich new data and ideas were discussed openly
and vigorously by all the participants. Contributors have been offered the opportunity to
publish short papers ("specials") in a thematicset, as part of the Journal of the GeologicalSociety. In the context of the topic of thismeeting, it was not felt that the opportunity to
publish inhibited individual contributors frompresenting n ew data or innovative ideas. It was
widely felt that the meeting was very successful,with many delegates commenting favorably on
its format.
contributed by A ndy Morton

Synopses of recent meetings are welcomedplease send your -200 word review to Mike
Coffin or John Mahoney.

H f§ftf!**¥£¥ Ji.: %*&fih k t &!WkM*ii.§ F+-ti@t&i"Mi!Wi¥2 aewt't!

UPs and ODP
The Ocean Drilling Program has recently estab lished formal links with major international
geoscientific organizations, including lAVCEI's
Commission on Large-Volume Basaltic Provinces.
This reflects both the broadening of ODP's
scientific interests and ODP's increasing internationalization. In September, ODP requested that
our Commission assist ODP in revising its Long
Range Plan (draft text is available to Commission
members-see "Commission Products andServices" below), to which the Steering Committee
has responded initially. This commences anongoing dialogue between ODP and our Commission, to which Commission members are encouraged to contribute. Mike Coffin represents our
Commission within the ODP advisory structure,
as a member of the Lithosphere Panel, andwelcomes input from Commission members.
In December of each year, the Planning Commit-

tee of JOIDES Uoint Oceanographic Institutions
for Deep Earth Sampling) determines the scientific program for the JOIDES Resolution one year
in advance, i.e., in December 1994, the programfor 1996 will be planned. The scientific programis based primarily on input from the four thematic panels of JOIDES- Lithosphere, Tectonics,
Ocean History, and Sedimentary & Geochemical
Processes-which evaluate drilling proposals
twice each year. LIPs fared extremely well in twoof the panels' Fall (northern hemisphere) 1994
rankings: the Lithosphere Panel ranked the
Caribbean flood b asalt province #1, and theTectonics Panel ranked the Southeast Greenland
volcanic margin #2. Next month the JOIDES
Planning Committee will decide if and whenthese two provinces will be drilled-contact Mike
Coffin for d etails.
The Ocean Drilling Program is proposal-driven,and anyone may submit a drilling proposal.
Guidelines for writing and submitting proposals
may be obtained from Rob Kidd or Julie Harris,
JOIDES Office, Dept. of Earth Sciences, Universityof Wales, Cardiff, PO Box 914, Cardiff CF1 3YE,
UK. Telephone 44.222.874.541. Facsimile
44.222.874.943. Internet: joides@cf.ac.uk.
Information on ODP's long-range thematic plans
may be obtained from the same address.

Upcoming Meetings
1994
5-9 December:
American Geophysical Union Fall Meeting, San Francisco, California, USA. Information:
AGU-Meetings Dept., 2000 Florida Ave., N.W., Washington, D.C. 20009, USA. Telephone:
1.202.462.6900. Facsimile: 1.202.328.0566. Internet: sbell@kosmos.agu.org

1995
4-7 January 1995:
Venus 11-Geology, Geophysics, Atmosphere, and Solar Wind Environment, Tucson,
Arizona, USA. Abstract deadline: 4 November 1994. Information: A. Schumann, Lunarand Planetary Laboratory, University of Arizona, Tucson, Arizona 85721, USA. Telephone 1.602.621.2902. Facsimile: 1.602.621.4933. Internet: amys@lpl.arizona.edu
3-7 April1995:
European Geophysical Society, Hamburg, Germany. Abstract deadline: 15 November
1994. Information: Philippe Charvis, ORSTOM, O.O.V., BP48, 06230, Villefranche-surmer, France. Note Symposium SE 18. "Geodynamic Processes at Ocean Ridges and Hot
Spots," convened by P. Charvis. Telephone 33.93.76.38.83. Facsimile: 33.93.76.37.68.
Internet: charvis@ccrv.obs-vlfr.fr
9-13 April1995:
European Union of Geosciences, Strasbourg, France. Abstract deadline: 30 November
1994. Information: EUG 8 Office @E.O.P.G., 5, rue Rene Descartes, Strasbourg Cedex
67084, France. Note Symposium XI-5, "Magmatism Associated with Active Plumes,"convened by M. Rabinowicz and N. Rogers. Telephone 33.88.41.63.93. Facsimile
33.88.41.17.66. Internet: eug@eopg.u-strasbg.fr
2-14 July 1995:
International Union of Geodesy and Geophysics XXI General Assembly, Boulder,
Colorado, USA. Abstract deadline: 1 February 1995. Information: IUGG XXI General
Assembly, c/ o American Geophysical Union, 2000 Florida Ave., NW, Washington, DC
20009, USA. Note IAVCEI Symposium V1, "Origin of Large Igneous Provinces," convened by M. Coffin, N. Arndt, and J. Ludden, scheduled for 6 July. Also note IAVCEI
Symposium V4, " Evolution of Large Volcanic Systems," convened by J. Pallister, K. Hon,and J. Cole, scheduled for 4 July; and Joint Symposia J$4, "Geochemical and Geqphysical Signatures of Mantle Plumes," convened.by W. White, L. Fleitout, B. Hager, and L.
Kellogg, scheduled for 11 July. Potential relevant field excursions include the ColumbiaRiver basalts, Yellowstone, and Wrangellia.
16-21 July 1995:
PLUME 2 - Conference, SchloB Ringberg, Tegernsee, Germany. Preregistration deadline:
15 November 1994. Information: Kerstin Lehnert, Max-Planck-Institut fur Chemie,
Postfach 3060, D-55020 Mainz, Germany. Telephone 49.6131.305260. Facsimile
49.6131.3 71051. Internet: kerstin@geobar.mpch-mainz.mpg.de
4-8 September 1995:
Third International Dyke Conference, Jerusalem, Israel. Paper deadline: 31 December
1994; abstract deadline: 31 May 1995. Information: Organizing Committee IDC-3 (Dr.
A. Heimann), Geological Survey of Israel, 30 Malkhe Yisrael St., jerusalem 95501, Israel.
Facsimile: 972.2.380688. Internet: dikeconf@vms.gsi.gov.il~

5Commission Products and Services
LIPs on Internet

Anonymous FfP

LIPs have an internet presence, accessible via
standard internet tools. The Commission's LIPbibliography of -1500 references, directory of-200 members, and digital database of LIP areas(Figure 1 of Coffin & Eldholm, Reviews of Geophysics, 1994) are available, as well as thecalendar of events, text versions of The LIP
Reader, and the September 1994 draft of the ODPLong Range Plan.
The internet site is currently set up as a Gopher
directory which allows users to log in with ·anonymous ftp or World Wide Web (WWW) tools, ·such as NCSA Mosaic. ·The directory is in theprocess of being relocated to a workstation at theInstitute for Geophysics. When the Institute's
Web server is installed, the LIPs directory will beenhanced for WWW browsers. Ideas on how thesite could be improved are most welcome. For
copies of materials on Macintosh diskette, please
send a blank 3.5 inch diskette to Mike.

With ftp, open ftp.cc.utexas.edu, use the loginname anonymous and your internet address as a
password. Then change directory to / pub/lips.
When the changeover is complete, use the sameprocedure to ftp to gopher.ig.utexas.edu and cd to/research/lips.

The

LIP Reader
Suite 300, Third Floor
8701 North Mopac Expressway
Austin, Texas 78759-8397 USA

GopherUsing your Gopher client software, open
gopher.ig.utexas.edu. Navigate to UTIG Research/
LIPS. The old gopher address will continue to work
for a few more months.

World Wide Web
The Universal Resource Locator (URL) will b egopher://gopher.ig.utexas.edu: 70/ 11/ research/lips.