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Figure F12. Close-up photographs of hyaloclastites, Hole U1383C. A, B. Hyaloclastite with angular and poorly sorted cryptocrystalline and glassy clasts (interval 336-U1383C-13R-1, 58–61 cm [Piece 12]): (A) the most altered glass shards are typically replaced by reddish- to yellowish-brown palagonite, (B) concentric alteration rinds in larger basaltic clasts. The white cement around the clasts is essentially composed of zeolite. Field of view (FOV) = 1.5 cm. C, D. Interval 336-U1383C-9R-3, 49–54 cm (Piece 7): (C) chilled margin of phyric basalt with crypto- to microcrystalline groundmass grading into hyaloclastite, (D) internal structures of basalt clasts assembled with a jigsaw-puzzle fit and cemented by zeolite. Open vugs have a higher abundance of Fe oxyhydroxides with zeolite cement. Hairline veinlet network in cryptocrystalline to glassy clasts has incipient light gray alteration halos attributed to mesostasis alteration. FOV = 1.2 cm. Red box shows orientation of photograph relative to C.

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