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Th or collective redistirbution or collective of this by of any article portion SPECIAL ISSUE FEATURE in published been has is article

LARGE IGNEOUS , Volume 4, a quarterly journal of Th 19, Number PROVINCES AND or other means reposting, is only photocopy machine, permitted SCIENTIFIC DRILLING STATUS QUO AND A LOOK AHEAD e Oceanography Society. Copyright 2006 by Th Society. e Oceanography

BY MILLARD F. COFFIN, ROBERT A. DUNCAN, OLAV ELDHOLM, J. GODFREY FITTON, FRED A. FREY, HANS CHRISTIAN LARSEN, JOHN J. MAHONEY, with the approval of Th of approval the with ANDREW D. SAUNDERS, ROLAND SCHLICH, AND PAUL J. WALLACE

A rich mosaic of disparate crustal types entifi c ocean drilling has signifi cantly Ocean, two to the Ontong Java Permission reserved. Society. All rights e Oceanography is gran characterizes the beneath the . advanced understanding of LIPs. Herein in the western equatorial Pacifi c Ocean, all correspondence to: Society. Send [email protected] e Oceanography or Th Although “normal” oceanic ap- we focus on signifi cant outcomes of ten and one to the Chagos-Maldive-Laccad- proximately 7-km thick is by far the LIP-dedicated expeditions between 1985 ive Ridge and in the most prevalent, abnormally thick oce- and 2000 and also highlight prospects (Table 1). Complementary anic-type crust of large igneous prov- for future drilling efforts. The ten ex- geophysical and/or onshore geological inces (LIPs) also forms a signifi cant peditions include three to the volcanic investigations have added signifi cant component of the marine realm (e.g., margins of the North Atlantic Tertiary value to all of these expeditions. Coffi n and Eldholm, 1994; Mahoney Igneous Province, four to the Kerguelen Terrestrial LIPs are massive and rapid and Coffi n, 1997; Saunders, 2005). Sci- Plateau/ LIP in the Indian crustal emplacements of predominantly mafi c (Fe- and Mg-rich) rock that did ted in teaching to and research. copy this for use Repu article Millard F. Coffi n (mcoffi [email protected]) is Professor, Ocean Research Institute, Th e not form by seafl oor spreading or sub- University of Tokyo, Tokyo, Japan. Robert A. Duncan is Professor, College of Oceanic and duction (Coffi n and Eldholm, 1994). Atmospheric Sciences, Oregon State University, Corvallis, OR, USA. Olav Eldholm is Profes- LIPs may be the dominant type of MD 20849-1931, USA. 1931, Rockville, Box PO Society, e Oceanography sor, Department of Earth Science, University of Bergen, Bergen, . J. Godfrey Fitton on other terrestrial plan- is Professor, School of Geosciences, University of Edinburgh, Edinburgh, UK. Fred A. Frey is ets and moons of the solar system (e.g., Professor, Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Insti- Head and Coffi n, 1997). On Earth, LIP tute of Technology, Cambridge, MA, USA. Hans Christian Larsen is Vice President, IODP rocks are readily distinguishable from Management International, Sapporo, Japan. John J. Mahoney is Professor, School of Ocean mid-ocean ridge and -re- and Earth Science and Technology, University of Hawaii, Honolulu, HI, USA. Andrew D. lated arc rocks on the basis of petrology, Saunders is Professor, Department of , University of Leicester, Leicester, UK. Roland geochemistry, geochronology, physical blication, systemmatic reproduction, Schlich is Professor, Institut de Physique du Globe de Strasbourg (CNRS/ULP), EOST, Stras- volcanology, and geophysical data. LIPs bourg, France. Paul J. Wallace is Associate Professor, Department of Geological Sciences, occur within continents and , and University of Oregon, Eugene, OR, USA. include continental fl ood in the

150 Oceanography Vol. 19, No. 4, Dec. 2006 Table 1. Large Igneous Provinces, ODP Legs, and References

Large Igneous Province ODP Leg References 104 Eldholm, Thiede, Taylor, et al., 1987, 1989 Larsen, Saunders, Clift, et al., 1994; 152 North Atlantic Tertiary Saunders, Larsen, and Wise, 1998 Duncan, Larsen, Allan, et al., 1996; 163 Larsen, Duncan, Allan, and Brooks, 1999 119 Barron, Larsen, et al., 1989, 1991 Schlich, Wise, et al., 1989; 120 Wise, Schlich, et al., 1992 / Peirce, Weissel, et al., 1989; 121 Broken Ridge Weissel, Peirce, Taylor, Alt, et al., 1991 Coffi n, Frey, Wallace, et al., 2000; 183 Wallace, Frey, Weis, and Coffi n, 2002; Frey, Coffi n, Wallace, and Quilty, 2003 Kroenke, Berger, Janecek, et al., 1991; 130 Berger, Kroenke, Mayer, et al., 1993 Mahoney, Fitton, Wallace, et al., 2001; 192 Fitton, Mahoney, Wallace, and Saunders, 2004a, 2004b Chagos-Maldive-Laccadive Ridge/ Backman, Duncan, et al., 1988; 115 Mascarene Plateau Duncan, Backman, Peterson, et al., 1990

former, and volcanic passive margins, centers (e.g., Eldholm and Coffi n, 2000). marine fl ows. Individual fl ows can ex- oceanic , submarine ridges, and LIP observations therefore suggest that tend for hundreds of kilometers, be tens ocean-basin fl ood basalts in the latter dynamic, non-steady-state circulation to hundreds of meters thick, and may (Figures 1 and 2). Transient LIPs and within Earth’s mantle has been impor- have volumes of more than 103 km3 (e.g., associated persistent, age-progressive tant for at least the last 250 million years Tolan et al., 1989). In addition to mafi c volcanic chains (“hot-spot tracks”) are and probably much longer, and there is a rock, silica-rich rock occurs in LIPs as commonly attributed to decompression strong potential for LIP emplacements to , intrusive rocks, and pyroclastic de- melting of hot, buoyant mantle ascend- contribute to, and perhaps even instigate, posits, and is mostly associated with the ing from Earth’s interior (e.g., Morgan, major environmental changes. initial and late stages of LIP magmatic 1971) and thus provide a window into activity (e.g., Bryan et al., 2002). Relative mantle processes. Magmatism associ- COMPOSITION, PHYSICAL to mid-ocean ridge basalts, LIP basalts ated with LIPs currently represents VOLCANOLOGY, CRUSTAL are compositionally more diverse (e.g., ~ 10 percent of the mass and energy fl ux STRUCTURE, & MANTLE ROOTS Kerr et al., 2000), and LIP rocks form in from Earth’s deep interior to its surface The uppermost crust of LIPs is domi- both subaerial and submarine settings. (e.g., Sleep, 1992). This fl ux shows dis- nantly mafi c extrusive rock similar to The maximum crustal thickness, in- tinct episodicity over geological time, originating at mid-ocean ridge cluding an extrusive upper crust, an in- in contrast to the relatively steady-state spreading centers; it most typically is trusive middle crust, and a lower crustal crustal at seafl oor spreading found as gently dipping subaerial or sub- body, of an oceanic LIP can be as great

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Figure 1. global LIP distribution, with transient (“plume head”) and persistent (“plume tail”) LIPs indi- cated in red and blue, respectively. LIPs are better preserved in the oceans where they are not subject to terrestrial erosional processes, off ering a prime target for scientifi c ocean drilling. Modifi ed from Coffi n and Eldholm (1994).

as ~ 40 km, determined from seismic Seismic wave velocities suggest that the beneath these three LIPs apparently re- and gravity studies of (Fig- middle crust is most likely gabbroic, and fl ect residual effects, primarily chemi- ure 1) (Darbyshire et al., 2000). Nearly that the lower crust is mafi c to ultra- cal and perhaps secondarily thermal, all of our knowledge of LIPs, however, mafi c, and perhaps metamorphic (e.g., of mantle (Gomer and Okal, is derived from the most accessible la- Eldholm and Coffi n, 2000). 2003). If proven to be common, roots vas forming the uppermost portions of Low-velocity zones have been ob- extending well into the mantle beneath crust. This extrusive upper crust may served by seismic imaging of the mantle oceanic LIPs would suggest that such exceed 10 km in thickness (e.g., Cof- beneath the oceanic Ontong Java Plateau LIPs contribute to continental initiation fi n and Eldholm, 1994). On the basis of (e.g., Richardson et al., 2000), as well as well as continental growth. Instead geophysical, predominantly seismic, data as under the continental of being subducted like normal oce- from LIPs, and from comparisons with (Kennett and Widiyantoro, 1999) and anic , LIPS may be accreted normal , it is believed that Paraná fl ood basalts (Vandecar et al., to the edges of continents, for example, the extrusive upper crust is underlain by 1995) (Figure 1). Interpreted as litho- obduction of Ontong Java Plateau ba- an intrusive middle crust, which in turn spheric roots or keels, the zones can salts onto the Solomon Island arc (e.g., is underlain by lower crust (“lower crust- extend to at least 500–600 km into the Hughes and Turner, 1977), and al body”) characterized by compressional mantle. In contrast to high-velocity roots accretion of Wrangellia (e.g., Richards seismic wave velocities of 7.0–7.6 km s-1 beneath most continental areas, and the et al., 1991) and Caribbean (e.g., Kerr (Figure 2). Dikes and sills are probably absence of lithospheric keels in most et al., 1997) LIPs to North and South common in the upper and middle crust. oceanic areas, the low-velocity zones America, respectively.

152 Oceanography Vol. 19, No. 4, Dec. 2006 DISTRIBUTION, TECTONIC a) SETTING, AND TYPES off-axis LIPs occur throughout the global ocean in purely intraplate settings and along present and former plate boundaries (Figure 1), although the tectonic set- ting of formation for many features on-axis (e.g., Kerguelen Plateau/Broken Ridge and Ontong Java Plateau) is unknown. If a LIP forms at a seafl oor-spreading axis, the entire crustal section may be LIP crust (Figure 2a, lower). Conversely, b) OCEAN BASIN if one forms in an intraplate setting or at a locus of continental breakup, pre- existing crust must be intruded and 7 km sandwiched by LIP , albeit to an extent not easily resolvable by cur- rent geological or geophysical techniques c) CONTINENTAL FLOOD BASALT (Figure 2a, upper, 2c). Volcanic passive margins form by excessive magmatism during continental breakup along the Continental trailing, rifted edges of continents (e.g., Crust Figure 2d; White and McKenzie, 1989). Continental breakup may be accom- panied (e.g., North Atlantic), preceded (e.g., Central Atlantic), followed (e.g., Kerguelen Plateau), or unaccompanied d) VOLCANIC MARGIN by LIP emplacement; passive continental Zone Post-opening sediment margins span a continuum from mag- ma-poor to volcanic. The deep ocean basins contain three morphologic types of transient LIPs. (1) Oceanic plateaus, Continental commonly isolated from major conti- Crust nents, are broad, typically fl at-topped features generally lying 2000 m or more LIP CRUST above the surrounding seafl oor. They can form at triple junctions (e.g., Shatsky Oceanic Crust Intrusives Rise), mid-ocean ridges (e.g., Iceland), or in intraplate settings (e.g., northern Figure 2. Schematic LIP plate tectonic settings and gross crustal structure. LIPs are em- Kerguelen Plateau). (2) Submarine ridg- placed in a variety of plate tectonic settings, yet are characterized by a common three- es are elongated, steep-sided elevations layer crustal structure, although crustal thickness varies considerably. LIP crustal com- ponents are: extrusive upper crust (X), middle crust (MC), and lower crustal body (LCB). of the seafl oor. Some may form along Normal oceanic crust, 7-km thick, is gray. Horizontal scale varies from a few hundred to transform plate boundaries (e.g., parts of more than a thousand kilometers. Modifi ed from Eldholm and Coffi n (2000).

Oceanography Vol. 19, No. 4, Dec. 2006 153 the Ninetyeast Ridge, Chagos-Maldive- nevertheless the 40Ar/39Ar incremental- nearly all or only part of Earth’s mantle; Laccadive Ridge, Mascarene Plateau). heating radiometric technique is having persistent magmatism has been consid- Oceanic plateaus and submarine ridges a particularly strong impact on stud- ered to result from steady-state mantle are the most enigmatic with respect ies of LIP volcanism. Geochronologi- plume “tails” penetrating the lithosphere, to the tectonic setting in which they cal studies of continental fl ood basalts which is moving relative to the plume formed. (3) Ocean-basin fl ood basalts (e.g., Siberian, Karoo/Ferrar, Deccan, (e.g., Richards et al., 1989) (Figures 1 (e.g., Nauru Basin and Caribbean LIP) Columbia River; Figure 1) suggest that and 3). Although plume models appear are the least-studied type of LIP, at least many LIPs are initially constructed from to explain the North Atlantic volcanic in situ, and consist of extensive subma- huge volumes (~ 105–107 km3) of mafi c margins relatively well, both the Ontong rine fl ows and sills lying above and post- erupted and intruded into local- Java Plateau (with its lack of signifi cant dating normal oceanic crust. In contrast ized regions of the crust over short in- uplift or subsidence and submarine em- to oceanic plateaus, ocean basin fl ood tervals (~ 105–106 years). Subsequently, placement environment) and Kerguelen basalts do not form topographic plateaus as observed in the ocean basins, chains Plateau/Broken Ridge (with its pro- (Figure 2b). of volcanoes associated with LIPs may longed and voluminous emplacement be constructed over signifi cantly lon- history) present signifi cant challenges for AGES ger intervals (107–108 years). Transient current versions of plume theory, despite Age control for marine LIPs is sparse magmatism during initial LIP formation the fact that the latter has been mod- because of their relative inaccessibil- commonly has been attributed to mantle eled numerically (Farnetani and Samuel, ity, generally low-potassium contents in plume “heads” reaching the base of the 2005; Lin and van Keken, 2005). mafi c rocks, and extensive alteration, but lithosphere following transit through

-

m m

k k

0 0 D” 1 6 mantle outer core inner core

4 6

Figure 3. Schematic cross section of Earth depicting sources of LIPs and hot spots and fate of subducting lithosphere. Transient LIPs are believed to originate either from a thermal boundary layer near the core-mantle boundary (D”) or from thermal or mechanical boundary layers associated with large low-velocity zones. Modifi ed from Coffi n and Eldholm (1994).

154 Oceanography Vol. 19, No. 4, Dec. 2006 LIPS AND MANTLE DYNAMICS LIPS AND THE ENVIRONMENT basaltic eruptions that released enor-

Transient, rapidly erupted LIPs are not The environmental effects of LIPs likely mous volumes of volatiles such as CO2, distributed uniformly in time. For exam- have been global (e.g., Wignall, 2005), S, Cl, and F. These extensive eruptions ple, many LIPs formed between 50 and particularly when conditions have been likely have caused massive melting of 150 million years ago, whereas relatively at or near a threshold state. Continental hydrates and explosive release few have formed during the past 50 mil- fl ood basalts, volcanic passive margins, where magma intruded carbon-rich sed- lion years (Figure 4). Episodicity of LIP and oceanic plateaus have formed by imentary strata along rifting continental emplacement likely refl ects variations widespread and voluminous subaerial margins (e.g., North Atlantic; Svensen in rates of mantle circulation, perhaps caused by growth and instability of ther- mal boundary layers in Earth’s interior; this episodicity is supported by inter- preted high rates of seafl oor spreading Magma Flux Magma Flux during a portion of the 50–150-million- (km3/yr) (km3/yr) 0 5 10 15 10 20 30 40 year interval, specifi cally during the 0 LIPs LIPs + MORs long Normal Superchron (~ 120 to ~ 80 million years ago). Thus, although LIPs manifest types of mantle processes distinct from those driving seafl oor spreading, waxing and waning rates of overall mantle circulation prob- ably affect both sets of processes. 50 Although LIPs are commonly as- cribed to having originated from mantle upwelling related solely to convection Age (Figure 3), alternative mechanisms have (Ma) also been proposed. Some LIPs may re- sult from plate divergence or fracturing above hotter-than-average shallow man- 100 CNS tle (e.g., Courtillot et al., 2003). Alterna- tively, the spatial, if not temporal, associ- preserved ation of fl ood basalts and impact craters on the Moon, as well as limited evidence on Earth, suggests that bolide impacts subduction may result in massive decompression correction melting of the mantle, accounting for the emplacement of some LIPs, for example, 150 the Ontong Java Plateau (e.g., Ingle and Figure 4. (LIP) magma production, corrected for subduction (left), and summed LIP and mid-ocean ridge (MOR) magma production (right) for Coffi n, 2004). Thus, multiple mecha- the last 150 million years. Overall, mafi c magma fl ux from both LIPs and mid-ocean nisms may be required to account for all ridges (MORs) was highest in mid-Cretaceous time. Th e subduction correction LIPs, both on Earth and elsewhere in our assumes that all oceanic crust is recirculated to the mantle over 200 million years and a constant average LIP 5-million-year production volume over the same period. solar system. Note diff erence in x-axis scales. CNS: Cretaceous Normal Superchron. Modifi ed from Eldholm and Coffi n (2000).

Oceanography Vol. 19, No. 4, Dec. 2006 155 et al., 2004) or in subaerial permafrost volcanism has been the latitude at which istry (e.g., Devine et al., 1984; Stothers settings (Figure 5). A key factor affect- the LIP formed. In most basaltic erup- et al., 1986). Subaerial eruptions of large ing the magnitude of volatile release has tions, released volatiles remain in the volumes of basaltic magma at high-lati- been whether eruptions were subaerial troposphere. However, at high latitudes tude LIPs over relatively brief geological or submarine; hydrostatic pressure in- (e.g., Kerguelen Plateau), the tropopause intervals, including phreatomagmatic hibits vesiculation and degassing of rela- is relatively low, allowing larger mass fl ux eruptions (an explosive eruption result- tively soluble volatile components (H2O, (via basaltic fi ssure eruption plumes for ing from the interaction of magma with

S, Cl, F) during deep-water submarine transport) of SO2 and other volatiles into water) (e.g., Ross et al., 2005), would eruptions, although low-solubility com- the stratosphere. Sulfuric acid aerosol have increased potential to contribute to ponents (CO2, noble gases) are mostly particles that form in the stratosphere global environmental effects. degassed even at abyssal depths (e.g., after such eruptions have a longer resi- Highly explosive eruptions, such Moore and Schilling, 1973; Dixon and dence time and greater global dispersal as those documented from the North

Stolper, 1995). than if the SO2 remains in the tropo- and South Atlantic volcanic passive mar- Another important factor determin- sphere; therefore, they have greater ef- gins, the Red Sea, the Kerguelen Plateau, ing the environmental impact of LIP fects on climate and atmospheric chem- and continental fl ood basalts (e.g., Bryan

Increased Planetary Albedo Heterogeneous Chemistry N2O5 hN & OH ClONO2 HNO3 HCl ClO SO2, HCl, Ash, [CH4]

SO2 H2SO4 Warming Stratosphere

Nucleation and Particle Growth Rainout Removal H2O, HCl, Ash Processes Troposphere Cirrus Modification Infrared Land Bridges Extrusives Gateways Hydrothermal Activity Extrusives Upwelling Oceanic Crust Lower Crustal Body

Lower Crustal Body

Continental Flood Basalt Oceanic Plateau (off-axis)

Figure 5. Complex chemical and physical environmental eff ects associated with LIP formation. LIP eruptions can perturb the Earth-ocean-atmosphere system signifi cantly. Note that many oceanic plateaus form at least in part subaerially. Energy from solar radiation is hv, where h = Planck’s constant, and v = frequency of electromagnetic wave of solar radiation. Modifi ed from Coffi n and Eldholm (1994).

156 Oceanography Vol. 19, No. 4, Dec. 2006 et al., 2002) (Figure 1), have likely also black shales (oceanic anoxic events), high (e.g., Thordarson and Self, 1993). Al- injected both particulate material and production of hydrocarbons, mass ex- though produced a basaltic fl ow volatiles (SO2, CO2) directly into the tinctions of marine organisms, and radi- representing only ~ 1 percent of the vol- stratosphere. The total volume of felsic ations of marine fl ora and fauna. Tempo- ume of a typical (103 km3) transient LIP volcanic rocks in LIPs is poorly known, ral correlations between the intense puls- fl ow, the eruption’s environmental im- but such rocks may account for a small, es of igneous activity associated with LIP pact resulted in the deaths of 75 percent but important fraction of the volcanic formation and environmental changes of Iceland’s livestock and 25 percent of its deposits in LIPs. Signifi cant volumes of are far too strong to be pure coincidence population from starvation. explosive felsic volcanism would have (Figure 6)—far stronger, for example, further affected the global environment than the association of impacts and mass LIPSA KEY IODP INITIATIVE (e.g., Scaillet and MacDonald, 2006). extinctions. The most dramatic example Understanding the formation of LIPs LIP formation may have been respon- is the eruption of the Siberian fl ood ba- constitutes a fi rst-order problem in sible for some of the most dramatic and salts ~ 250 million years ago (Figures 1 Earth science, and as such, is a major, rapid changes in the global environment. and 6), which coincided with the largest high-priority initiative for the Integrated Between ~ 145 and ~ 50 million years extinction of plants and animals in the Ocean Drilling Program (IODP) (Coffi n, ago, the global oceans were characterized geological record (e.g., Renne and Basu, McKenzie, et al., 2001). Strong evidence by chemical and isotopic variations (es- 1991). Ninety percent of all species be- exists that many LIPs manifest a form pecially in C and Sr isotope ratios, trace came extinct at that time. On Iceland, of mantle dynamics not clearly related metal concentrations, and biocalcifi ca- the 1783–1784 eruption of Laki provides to ; the processes involved tion), relatively high temperatures, high the only historical record of the type of in their formation are critically impor- relative sea level, episodic deposition of volcanism that constructs transient LIPs tant for understanding both mantle and

Figure 6. Extinction of marine genera versus time (continuous line, blue fi eld), modifi ed from Sepkoski (1996), Deccan compared with eruption ages of LIPs (red columns). Strong temporal cor-

Ontong Java relation between LIPs and mass extinc- North Atlantic Columbia River Central Atlantic tions suggests causality. Th ree of the Karoo and Ferrar Karoo Emeishan, Panjal largest mass extinctions—the Permo-

Ethiopia and , Triassic-, and Creta- Paraná and Etendeka ceous-Tertiary—coincide with eruption Caribbean, ages of the , the Central Atlantic Magmatic Province, and the Kerguelen/Broken, Rajmahal Kerguelen/Broken, Deccan Traps, respectively. Modifi ed from White and Saunders (2005). See Figure 1 for locations of LIPs.

Oceanography Vol. 19, No. 4, Dec. 2006 157 crustal geodynamics. Many data also ogy and geochemistry, LIPs, combining observation, sampling, suggest that LIPs contribute episodically, • possible role of LIP volcanism as the remote and in situ data acquisition, and at times catastrophically, to global envi- dominant non-plate-tectonic heat- quantitative modeling to address the role ronmental change. Investigating relation- loss mechanism of all terrestrial of LIPs in planetary evolution. Strategies ships between their emplacements and planets, are also being developed for understand- major environmental changes is crucial • role of LIPs in the initiation of conti- ing the microbial ecosystems that may for advancing understanding of the Earth nents and continental growth, exist where fl uids fl ow within LIP crust. system. Nevertheless, we have literally • physical volcanology that modulates may mediate chemical only scratched the surface of 20–40-km particulate and aerosol release into the budgets by catalyzing and deriving en- thick in situ oceanic LIP crust: 0.914 km oceans and atmosphere, and governs ergy from a wide variety of geochemical into igneous crust is the deepest base- the eruption of basaltic fl ows cover- reactions. Scientists from a wide spec- ment penetration of a volcanic passive ing many thousands of km2, to un- trum of Earth science are involved in margin (Norwegian) and 0.233 km is the derstand paleoenvironmental forcing developing these new research initiatives. deepest penetration of an oceanic pla- functions and feedback loops associ- Implementation of such ambitious strat- teau (Kerguelen). However, in at least one ated with LIPs, egies would benefi t strongly both from a instance globally, 3–4 km of uppermost • volatile concentrations in LIP magmas NASA-style “mission” framework as well Ontong Java Plateau crust obducted onto and the volatile load delivered to the as from new collaborative site surveying the Solomon Islands (Petterson et al., oceans and atmosphere, to evaluate and drilling relationships between the 1997) allows direct sampling and study of potential paleoenvironmental impacts IODP and industry. a thicker section of submarine LIP crust. of LIPs, Scientifi c ocean drilling has played a The full consequences of LIP forma- • trace metal inventory and potential pivotal role in advancing knowledge of tion have only recently begun to be ap- consequences of LIP eruptions for LIPs. In the future, IODP promises to preciated, and scientifi c ocean drilling oceanic and atmospheric chemistry, play an even more critical role in identi- has a critical role in examining the fol- and hence for paleoenvironmental fying and describing the nature and con- lowing relationships between LIPs and changes, sequences of LIP activity in the evolution both Earth and planetary evolution: • possible connections between LIP of the solid Earth, and of its oceans, at- • implications for mantle convection events and acceleration/retardation of mosphere, and biosphere. and heat loss from the Earth’s inte- the evolution of life on Earth. rior through understanding LIP mass Since 1985, when we fi rst began to fo- ACKNOWLEDGEMENTS and energy fl uxes relative to those of cus scientifi c ocean drilling efforts on We thank the captains and crews of the mid-ocean ridges and arcs/backarcs oceanic LIPs, we have witnessed excit- JOIDES Resolution and the shipboard through geologic time, ing advances in LIP-related solid Earth and shore-based Ocean Drilling Pro- • interaction of LIP events and the plate and Earth system studies. In 2007, with gram support staff of Texas A&M Uni- tectonic cycle, especially continental the advent of three-platform IODP versity for their dedication and efforts. rifting and breakup, to evaluate tem- operations, scientists will have greatly L. Gahagan and T. Kanehara supplied poral relationships and causalities, enhanced two- and three-dimensional Figure 1, and Figures 3 and 5, respective- • temporal relationships between LIP seismic site surveying (academic and ly. R. Burger, P. Castillo, K. Condie, K. Fu- events and changes in the reversal commercial), drilling, logging, and bore- jioka, and E. Kappel provided construc- frequency of Earth’s magnetic fi eld to hole-monitoring capabilities to apply to tive reviews and editing. We are grateful investigate potential causality, LIP investigations. These new capabili- for the support of all of the Ocean Drill- • compositions of LIP magmatic rocks ties are stimulating community develop- ing Program and Integrated Ocean Drill- as “windows” into deep mantle petrol- ment of new strategies for understanding ing Program partner countries and con-

158 Oceanography Vol. 19, No. 4, Dec. 2006 sortia, including our respective Japanese gravity study. Earth and Planetary Science Let- 411–438 in Large Igneous Provinces: Continental, ters 181:409–428. Oceanic, and Planetary Flood Volcanism, J.J. Ma- (MFC), American (MFC, RAD, FAF, JJM, Devine, J.D., H. Sigurdsson, A.N. Davis, and S. Self. honey and M.F. Coffi n, eds. American Geophys- and PJW), Norwegian (OE), British (JGF 1984. Estimates of sulfur and chlorine yields to ical Union Geophysical Monograph 100. Amer- and ADS), Danish (HCL), and French the atmosphere from volcanic eruptions and ican Geophysical Union, Washington, D.C. potential climatic effects. Journal of Geophysical Hughes, G., and C. Turner. 1977. Upraised Pacifi c (RS) funding agencies. Research 89:6,309–6,325. Ocean fl oor, southern . Geological Soci- Dixon, J.E., and E.M. Stolper. 1995. An experimen- ety of America Bulletin 88:412–424. REFERENCES tal study of water and carbon dioxide solubili- Ingle, S.P., and M.F. Coffi n. 2004. Impact origin Backman, J., R.A. Duncan, et al. 1988. Proceedings ties in mid-ocean ridge basaltic liquids. Part II: for the greater Ontong Java Plateau? Earth and of the Ocean Drilling Program, Initial Reports, Applications to degassing. Journal of Petrology Planetary Science Letters 218:123–134. 115. Ocean Drilling Program, College Station, 36:1,633–1,646. Kennett, B.L.N., and S. Widiyantoro. 1999. A low TX, 1085 pp. Duncan, R.A., J. Backman, L.C. Peterson, et al. seismic wavespeed anomaly beneath north- Barron, J., B. Larsen, et al. 1989. Proceedings of the 1990. Proceedings of the Ocean Drilling Program, western : A seismic signature of the Dec- Ocean Drilling Program, Initial Reports, 119. Scientifi c Results, 115. Ocean Drilling Program, can plume? Earth and Planetary Science Letters Ocean Drilling Program, College Station, TX, College Station, TX, 887 pp. 165:145–155. 942 pp. Duncan, R.A., H.C. Larsen, J.F. Allan, et al. 1996. Kerr, A.C., J. Tarney, G.F. Marriner, A. Nivia, and Barron, J., B. Larsen, et al. 1991. Proceedings of the Proceedings of the Ocean Drilling Program, Ini- A.D. Saunders. 1997. The Caribbean-Colom- Ocean Drilling Program, Scientifi c Results, 119. tial Reports, 163. Ocean Drilling Program, Col- bian Cretaceous igneous province: The internal Ocean Drilling Program, College Station, TX, lege Station, TX, 279 pp. anatomy of an oceanic plateau. Pp. 123–144 in 1003 pp. Eldholm, O., and M.F. Coffi n. 2000. Large igneous Large Igneous Provinces: Continental, Oceanic, Berger, W.H., L.W. Kroenke, L.A. Mayer, et al. 1993. provinces and plate tectonics. Pp. 309–326 in and Planetary Flood Volcanism, J.J. Mahoney Proceedings of the Ocean Drilling Program, Sci- The History and Dynamics of Global Plate Mo- and M.F. Coffi n, eds. American Geophysical entifi c Results, 130. Ocean Drilling Program, tions, M.A. Richards, R.G. Gordon, and R.D. Union Geophysical Monograph 100. American College Station, TX, 867 pp. van der Hilst, eds. American Geophysical Union Geophysical Union, Washington, D.C. Bryan, S.E., T.R. Riley, D.A. Jerram, C.J. Stephens, Geophysical Monograph 121. American Geo- Kerr, A.C., R.V. White, and A.D. Saunders. 2000. and P.T. Leat. 2002. Silicic volcanism: An un- physical Union, Washington, D.C. LIP reading: Recognizing oceanic plateaux dervalued component of large igneous prov- Eldholm, O., J. Thiede, E. Taylor, et al. 1987. Pro- in the geological record. Journal of Petrology inces and volcanic rifted margins. Pp. 97–118 ceedings of the Ocean Drilling Program, Initial 41:1,041–1,056. in Volcanic Rifted Margins, M.A. Menzies, S.L. Reports, 104. Ocean Drilling Program, College Kroenke, L.W., W.H. Berger, T.R. Janecek, et al. Klemperer, C.J. Ebinger, and J. Baker, eds. Geo- Station, TX, 783 pp. 1991. Proceedings of the Ocean Drilling Program, logical Society of America Special Paper 362, Eldholm, O., J. Thiede, E. Taylor, et al. 1989. Pro- Initial Reports, 130. Ocean Drilling Program, Boulder, CO. ceedings of the Ocean Drilling Program, Scientifi c College Station, TX, 1,240 pp. Coffi n, M.F., and O. Eldholm. 1994. Large igneous Results, 104. Ocean Drilling Program, College Larsen, H.C., A.D. Saunders, P.D. Clift, et al. 1994. provinces: Crustal structure, dimensions, and Station, TX, 1141 pp. Proceedings of the Ocean Drilling Program, Ini- external consequences. Reviews of Geophysics Farnetani, C.G., and H. Samuel. 2005. Beyond the tial Reports, 152. Ocean Drilling Program, Col- 32:1–36. thermal plume paradigm. Geophysical Research lege Station, TX, 977 pp. Coffi n, M.F., F.A. Frey, P.J. Wallace, et al. 2000. Pro- Letters 32, doi:10.1029/2005GL022360. Larsen, H.C., R.A. Duncan, J.F. Allan, and K. ceedings of the Ocean Drilling Program, Initial Fitton, J.G., J.J. Mahoney, P.J. Wallace, and A.D. Brooks, eds. 1999. Proceedings of the Ocean Reports, 183.Ocean Drilling Program, College Saunders, eds. 2004a. Origin and Evolution of Drilling Program, Scientifi c Results, 163. Ocean Station, TX [CD-ROM]. the Ontong Java Plateau. Geological Society Drilling Program, College Station, TX, 173 pp. Coffi n, M.F., J.A. McKenzie et al. 2001. Earth, Special Publication 229. Geological Society, Lin, S.-C. and P. van Keken. 2005. Multiple volcanic Oceans, and Life. Scientifi c Investigations of the London, United Kingdom, 374 pp. episodes of fl ood basalts caused by thermome- Earth System using Multiple Drilling Platforms Fitton, J.G., J.J. Mahoney, P.J. Wallace, and A.D. chanical mantle plumes. Nature 436:250–252. and New Technologies. Integrated Ocean Drill- Saunders, eds. 2004b. Proceedings of the Ocean Mahoney, J.J., and M.F. Coffi n, eds. 1997. Large Ig- ing Program Initial Science Plan, 2003–2013. Drilling Program, Scientifi c Results, 192. Ocean neous Provinces: Continental, Oceanic, and Plan- International Working Group Support Offi ce, Drilling Program, College Station, TX [CD- etary Flood Volcanism. Geophysical Monograph Washington, D.C., 110 pp. [Online] Available ROM]. 100. American Geophysical Union, Washington, at: http://www.iodp.org/isp [last accessed Sept Frey, F.A., M.F. Coffi n, P.J. Wallace, and P.J. Quilty, D.C., 438 pp. 19, 2006]. eds. 2003. Proceedings of the Ocean Drilling Mahoney, J.J., J.G. Fitton, P.J. Wallace, et al. 2001. Courtillot, V., A. Davaille, J. Besse, and J. Stock. Program, Scientifi c Results, 183. Ocean Drilling Proceedings of the Ocean Drilling Program, Ini- 2003. Three distinct types of hotspots in the Program, College Station, TX, [CD-ROM]. tial Reports, 192. Ocean Drilling Program, Col- Earth’s mantle. Earth and Planetary Science Let- Gomer, B.M., and E.A. Okal. 2003. Multiple-ScS lege Station, TX, [CD-ROM]. ters 205:295–308. probing of the Ontong-Java Plateau. Physics of Moore, J.G., and J.-G. Schilling. 1973. Vesicles, Darbyshire, F.A., R.S. White, and K.F. Priestley. the Earth and Planetary Interiors 138:317–331. water, and sulfur in Reykjanes Ridge basalts. 2000. Structure of the crust and uppermost Head, III, J.W., and M.F. Coffi n. 1997. Large Igne- Contributions to Mineralogy and Petrology mantle of Iceland from a combined seismic and ous Provinces: A planetary perspective. Pp. 41:105–118.

Oceanography Vol. 19, No. 4, Dec. 2006 159 Morgan, W.J. 1971. Convection plumes in the lower no. 1986. Basaltic fi ssure eruptions, plume mantle. Nature 230:42. heights, and atmospheric aerosols. Geophysical Peirce, J., J. Weissel, et al. 1989. Proceedings of the Research Letters 13:725–728. Ocean Drilling Program, Initial Reports, 121. Svensen, H., S. Planke, A. Malthe-Sørenssen, B. Ocean Drilling Program, College Station, TX, Jamtveit, R. Myklebust, T. Rasmussen Eidem, 1,000 pp. and S.S. Rey. 2004. Release of methane from a Petterson, M.G., C.R. Neal, J.J. Mahoney, L.W. volcanic basin as a mechanism for initial Eo- Kroenke, A.D. Saunders, T.L. Babbs, R.A. Dun- cene global warming. Nature 429:542–545. can, D. Tolia, and B. McGrail. 1997. Structure Thordarson, T., and S. Self. 1993. The Laki (Skaftár and deformation of north and central Malaita, Fires) and Grímsvötn eruptions in 1783–1785. Solomon Islands: Tectonic implications for the Bulletin of Volcanology 55:233–263. Ontong Java Plateau-Solomon arc collision, and Tolan, T.L., S.P. Reidel, M.H. Beeson, J.L. Anderson, for the fate of oceanic plateaus. Tectonophysics K.R. Fecht, and D.A. Swanson. 1989. Revisions 283:1–33. to the estimates of the areal extent and volume Renne, P.R., and A.R. Basu. 1991. Rapid eruption of the Columbia River Basalt Group. Pp. 1-20 of the Siberian traps fl ood basalts at the Permo- in Volcanism and Tectonism in the Columbia Triassic boundary. Science 253:175–178. River Flood-Basalt Province, S.P. Reidel and P.R. Richards, M.A., R.A. Duncan, and V.E. Courtillot. Hooper, eds. Geological Society of America 1989. Flood basalts and hot-spot tracks: plume Special Paper 239. Geological Society of Ameri- heads and tails. Science 246:103–107. ca, Boulder, CO. Richards, M.A., D.L. Jones, R.A. Duncan, and Vandecar, J.C., D.E. James, and M. Assumpção. D.J. DePaolo. 1991. A initiation 1995. Seismic evidence for a mantle model for the formation of Wrangellia and plume beneath South America and implications other oceanic fl ood basalt plateaus. Science for plate driving forces. Nature 378:25–31. 254:263–267. Wallace, P.J., F.A. Frey, D. Weis, and M.F. Coffi n, Richardson, W.P., E.A. Okal, and S. Van der Lee. eds. 2002. Origin and Evolution of the Kerguel- 2000. Rayleigh-wave tomography of the On- en Plateau, Broken Ridge, and Kerguelen Archi- tong-Java Plateau. Physics of the Earth and Plan- pelago. Journal of Petrology 43:1,105–1,413. etary Interiors 118:29–51. Weissel, J., J. Peirce, E. Taylor, J. Alt, et al. 1991. Pro- Ross, P.-S., I. Ukstins Peate, M.K. McClintock, Y.G. ceedings of the Ocean Drilling Program, Scientifi c Xu, I.P. Skilling, J.D.L. White, and B.F. Hough- Results, 121. Ocean Drilling Program, College ton. 2005. Mafi c volcaniclastic deposits in fl ood Station, TX, 990 pp. basalt provinces: A review. Journal of Volcanol- White, R.S., and D.P. McKenzie. 1989. Magmatism ogy and Geothermal Research 145:281–314. at rift zones: The generation of volcanic con- Saunders, A.D., ed. 2005. Large Igneous Provinces: tinental margins and fl ood basalts. Journal of Origin and Environmental Consequences. Ele- Geophysical Research 94:7,685–7,729. ments 1:259–292. White, R.V., and A.D. Saunders. 2005. Volcanism, Saunders, A.D., H.C. Larsen, and S.W. Wise, Jr., eds. impact and mass extinctions: Incredible or 1998. Proceedings of the Ocean Drilling Program, credible coincidences. Lithos 79:299–316. Scientifi c Results, 152. Ocean Drilling Program, Wignall, P. 2005. The link between large igneous College Station, TX, 554 pp. province eruptions and mass extinctions. Ele- Scaillet, B., and R. MacDonald. 2006. Experimental ments 1:293–297. and thermodynamic constraints on the sulphur Wise, Jr., S.W., R. Schlich, et al. 1992. Proceedings yield of peralkaline and metaluminous silicic of the Ocean Drilling Program, Scientifi c Results, fl ood eruptions. Journal of Petrology 47:1,413– 120. Ocean Drilling Program, College Station, 1,437. TX, 1155 pp. Schlich, R., S.W. Wise, Jr., et al. 1989. Proceedings of the Ocean Drilling Program, Initial Reports, WEB RESOURCES 120. Ocean Drilling Program, College Station, TX, 648 pp. • www.largeigneousprovinces.org Sepkoski, J.J. 1996. Patterns of Phanerozoic extinc- • www.mantleplumes.org tion: a perspective from global data bases. Pp. 35-51 in Global Events and Event Stratigraphy, O.H. Walliser, ed. Springer, Berlin. Sleep, N.H. 1992. volcanism and mantle plumes. Annual Review of Earth and Planetary Sciences 20:19–43. Stothers, R.B., J.A. Wolff, S. Self, and M.R. Rampi-

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