TEXTURAL AND MICROANALYSIS OF IGNEOUS ROCKS: TOOLS ...

lations. Reprocessing of intrusive and extrusive MORB materials by ascending
plume magmas would be evident in CSDs as crystal accumulation (assuming only
partial resorption of the debris; e.g., [98]) and the presence of partially resorbed
plagioclase crystals. Late crystallizing plagioclase would reflect growth from a
hybridized magma, whereas entrained crystals would generally have MORB sig-
natures.
Hypothesis 3. The melt source was entirely related to the Hawaiian hotspot.
Ascending hotspot magmas passed through a complex magma chamber system
where they picked up crystal debris leading to curved CSDs. There is no evidence
of distinct MORB or OIB end-members. Compositional variations are ascribed
to variations in melting of a single heterogeneous source and variations in shallow
magma chamber dynamics over time.
1.7.3 The Kerguelen Plateau’s Western Salient - Elan Bank, Southern Indian
Ocean
The submarine Kerguelen Plateau (KP) and Broken Ridge constitute the sec-
ond largest oceanic LIP on Earth and rise up to 4 km above the surrounding
Indian Ocean basin (Fig. 4.1). Current sampling of the Cretaceous portion of the
KP has been done via drilling at 11 drill sites during Ocean Drilling Program
Legs 119, 120, and 183. Prior to Leg 183 drilling a number of workers suggested
that continental crust was involved during the petrogenesis some KP basalts (e.g.,
[51, 92]). Drilling at Site 1137 on Elan Bank confirmed hypotheses of continental
crust involvement when clasts of garnet-biotite gneiss were recovered from a flu-
vial conglomerate unit (Unit 6 in Fig. 4.2) [33, 74]. Nicolaysen et al. [111] and
Frey et al. [49] suggested that during the break up of the Gondwana superconti-
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