Lower Cretaceous Volcanic Rocks on Continental Margins and Their Relationship to the Kerguelen Plateau

Storey, Michael; Kent, R. W.; Saunders, A. D.; Salters, Vincent J. M.; Hergt, Janet; Whitechurch, Hubert; Sevigny, J. H.; Thirlwall, M. F.; Leat, P. T.; Ghose, Naresh Chandra; Gifford, M.G.

doi:10.2973/odp.proc.sr.120.118.1992

Cited by 78 publications

(77 citation statements)

References 55 publications

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“…This is the ¢rst unequivocal evidence of continental crust from the Kerguelen Plateau and Broken Ridge. Previous geochemical studies of basalt from the SKP and eastern Broken Ridge identi¢ed a component derived from continental crust [44,46], but the mechanism for incorporation of a continental component into the oceanic plateau was unconstrained. Possible processes range from recycling of continental material into a deep mantle plume to contamination of mantle-derived basaltic magma by fragments of continental crust isolated in the embryonic Indian Ocean crust by spreading center jumps during early sea£oor spreading between Antarctica and India.…”

Section: Discussionmentioning

confidence: 99%

Origin and evolution of a submarine large igneous province: the Kerguelen Plateau and Broken Ridge, southern Indian Ocean

Frey

Coffin

Wallace³

et al. 2000

Earth and Planetary Science Letters

217

142

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Oceanic plateaus form by mantle processes distinct from those forming oceanic crust at divergent plate boundaries. Eleven drillsites into igneous basement of Kerguelen Plateau and Broken Ridge, including seven from the recent Ocean Drilling Program Leg 183 (1998^99) and four from Legs 119 and 120 (1987^88), show that the dominant rocks are basalts with geochemical characteristics distinct from those of mid-ocean ridge basalts. Moreover, the physical characteristics of the lava flows and the presence of wood fragments, charcoal, pollen, spores and seeds in the shallow water sediments overlying the igneous basement show that the growth rate of the plateau was sufficient to form subaerial landmasses. Most of the southern Kerguelen Plateau formed at V110 Ma, but the uppermost submarine lavas in the northern Kerguelen Plateau erupted during Cenozoic time. These results are consistent with derivation of the plateau by partial melting of the Kerguelen plume. Leg 183 provided two new major observations about the final growth stages of the Kerguelen Plateau. 1: At several locations, volcanism ended with explosive eruptions of volatilerich, felsic magmas; although the total volume of felsic volcanic rocks is poorly constrained, the explosive nature of the eruptions may have resulted in globally significant effects on climate and atmospheric chemistry during the late-stage, subaerial growth of the Kerguelen Plateau. 2: At one drillsite, clasts of garnet^biotite gneiss, a continental rock, occur in a fluvial conglomerate intercalated within basaltic flows. Previously, geochemical and geophysical evidence has been used to infer continental lithospheric components within this large igneous province. A continental geochemical signature in an oceanic setting may represent deeply recycled crust incorporated into the Kerguelen plume or continental fragments dispersed during initial formation of the Indian Ocean during breakup of Gondwana. The clasts of garnet^biotite gneiss are the first unequivocal evidence of continental crust in this oceanic plateau. We propose that during initial breakup between India and Antarctica, the spreading center jumped northwards transferring slivers of the continental Indian plate to oceanic portions of the Antarctic plate. ß

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Section: Discussionmentioning

confidence: 99%

Origin and evolution of a submarine large igneous province: the Kerguelen Plateau and Broken Ridge, southern Indian Ocean

Frey

Coffin

Wallace³

et al. 2000

Earth and Planetary Science Letters

217

142

View full text Add to dashboard Cite

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“…Paleolatitudes determined from paleomagnetic data and models of hotspot motion [3] both suggest that the Kerguelen plume was V10 ‡ farther north at 110 Ma. The Kerguelen hotspot has also been implicated in the formation of the Bunbury basalts (123^132 Ma [12,13]) and the volcanics of the Western Australian margin (136^96 Ma [14]); however, its involvement is di⁄cult to reconcile with its presentday position.…”

Section: Introductionmentioning

confidence: 99%

Geodynamic implications of moving Indian Ocean hotspots

O’Neill

Müller

Steinberger

2003

Earth and Planetary Science Letters

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The reconstructed positions of many of the Indian Ocean intraplate volcanic features are inconsistent with the present positions of the hotspots to which they have been ascribed. The discrepancy can be explained by the past motion of the hotspots themselves, and in the errors introduced in an absolute plate model based on fixed hotspots. Previous models for the motion of hotspots in the Indian Ocean (e.g. [Steinberger and O'Connell, in press]. We find a motion of V7 ‡ south for the Kerguelen plume, similar to previous models [Antretter et al., op. cit.]. This motion alleviates the discrepancies in the position of the Kerguelen plume and its purported involvement in the formation of the Ninetyeast Ridge, Rajmahal Traps, Bunbury basalts and assorted volcanics of the Western Australian margin. We find a motion of 5 ‡ north and 7 ‡ south for the Reunion and Marion plumes, respectively. The motion of the Reunion hotspot is consistent with paleolatitude estimates. The apparent fixity of the Marion hotspot [Torsvik et al., Earth Planet. Sci. Lett. 164 (1998) 221^232] is not well-constrained, but may be due to the combination of hotspot motion and true polar wander acting in opposing directions. We present revised absolute finite rotations for the Indian plate for the last 65 Ma based on the motion of these hotspots, which place India farther north in the past than for fixed hotspot models. ß

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“…Similar patterns have been ob erved in several tectonic settings including true oceanic domains (ridges and plateaus), passive margins and evolved continental rifts. A sociated E-MORB and N-MORB have been found in active ridges (mainly the Mid-Atlantic Ridge in the FAMOUS area [18] but also the East Pacific Rise [19]), oceanic plateaus and/or their margins (Nauru [20][21][22], Ontong Java [23], or Kerguelen [24,25]) and seamounts [26]. E-MORB may have resulted from the mixing of N-MORB with more primitive alkaline-type magma formed during an early stage of hot spot volcanism [27].…”

Section: Petrologic Discussionmentioning

confidence: 99%

Extensional to compressive Mesozoic magmatism at the SE Eurasia margin as recorded from the Meratus ophiolite (SE Borneo, Indonesia)

et al. 1999

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-The Meratus ophiolitic series (SE Borneo) present a specific assemblage that have recorded (I) a continental extensional episode mostly seen within the peridotites and 2) later subduction-relat ed magmatic events marked by the emplacement of calc-alkaline magmas. These events relate the magmatic activity and geodynamic evolution of the SE Eurasia margin in Mesozoic times. The ophiolitic series comprise ultramafic rocks with minor metavolcanic rocks. The ultramafic rocks include dominant Iherzolites and pyroxenites with rather scarce harzburgites and dunites. Spinel peridotite, mineral chemistry data and bulk rock Rare Earth Element (REE) abundances show that most rocks underwent a low degree of partial melting. However, a few samples display significant depletions in Light REE (LREE), which are interpreted as the result of fractional melting under shallow conditions. Plagioclase-bear ing peridotites are characterized by high REE abundances which also point to a very low degree of melting followed by reequilibration in the plagioclase facies, as seen from phase chemistry data. These peridotites are locally crosscut by dikelets containing high-temperatur e Kand Cr-rich amphiboles. Lavas closely associated with the Meratus peridotites have REE compositions ranging from the ones typical of enriched MORB (E-MORB) to normal MORB (N-MORB) types. We believe that the Meratus peridotites represent a fragment of subcontinental lithospheric mantle that locally suffered a low degree of fractional melting during the last stages of a continental rifting phase, in agreement with the presence of metamorphic K-and Cr-rich amphiboles in the peridotites. The E-MORB basalts might result from the melting of an enriched subcontinental lithosphere thermally eroded during the rifting phase by rising asthenosphere which might have produced N-MORB volcanic rocks. Back-arc basin basalts (BABB) now associated with E-MORB and N-MORB have also been found in the metamorphic soles of the peridotites. These rocks would have formed in a back-arc basin now accreted to the eastern margin of Eurasia. The latter are partly covered by calc-alkaline magmatism (Alino Formation). The ophiolitic series was later crosscut by calc-alkaline melts (Manunggul Formation). The Meratus ophiolitic series hence displays a dual origin. They witness I) a continental episode mostly seen within the peridotites, and 2) later subductionrelated events marked by the emplacement of calc-alkaline magmas. © Elsevier, Paris ophiolite I geochemistry I peridotites I continental margin I South East Asia Resume -L'ophiolite des Meratus (SE de Borneo Indonesie) : temoin d'un magmatisme extensif puis co';pressif Ie long de la marge sud-est eurasienne. Cet article montre que I'ophiolit~des Meratus (SE de Borneo, Indonesie) represent~un ancien fragment du manteau lithospherique souscontmental forme au cours des derniers stades de rifting Ie long de la marge SE eurasienne probablement au debut du Mesozoi'que, puis tardivement obductee comme Ie temoigne Ie magmatisme calco-alc...

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Lower Cretaceous Volcanic Rocks on Continental Margins and Their Relationship to the Kerguelen Plateau

Cited by 78 publications

References 55 publications

Origin and evolution of a submarine large igneous province: the Kerguelen Plateau and Broken Ridge, southern Indian Ocean

Origin and evolution of a submarine large igneous province: the Kerguelen Plateau and Broken Ridge, southern Indian Ocean

Geodynamic implications of moving Indian Ocean hotspots

Extensional to compressive Mesozoic magmatism at the SE Eurasia margin as recorded from the Meratus ophiolite (SE Borneo, Indonesia)

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