Inside the magma chamber of a dying ridge segment in the Oman ophiolite

Adolphe Nicolas (1, 2) , Françoise Boudier (1, 2)

1 Géosciences Montpellier
2 Manteau et Interfaces

Search String Advanced > Saved Searches >ARTICLE TOOLS Get PDF (3653K) Save to My Profile E-mail Link to this Article Export Citation for this Article Get Citation Alerts Request PermissionsMore Sharing ServicesShare|Share on citeulikeShare on facebookShare on deliciousShare on www.mendeley.comShare on twitter Abstract Article References Cited ByView Full Article (HTML) Enhanced Article (HTML) Get PDF (3653K)AbstractFor the first time, the crystallized remnant of an oceanic ridge magma chamber is documented in the Oman ophiolite. It exists in the centre of a 40 km long monoclinal ridge (Jebel Dihm, Wadi Tayin massif), exposing a full crustal section perpendicular to the spreading direction. New detailed mapping supported by U-Pb zircon geochronology suggests that the active, fast-spreading ridge that died just prior to detachment of the ophiolite is preserved and largely intact. Our observations provide insights into the crystallizing mush zone of a magma chamber, before it crosses the external walls and solidifies as deformed gabbros. Our data provide new constraints on the shape and internal dynamics of a magma chamber, including gabbro subsidence from the floor of a perched melt lens and the limited contribution of sills to crustal accretion. By locating precisely the palaeo-ridge axis, prior full spreading rate estimates can be increased to ~140 km Ma−1.

Mots clés: Oman ophiolite

Domaines: Pétrographie

Adolphe Nicolas, Françoise Boudier. Inside the magma chamber of a dying ridge segment in the Oman ophiolite. Terra Nova, 2015, 27 (1), pp.69-76. ⟨10.1111/ter.12130⟩. ⟨hal-01121586⟩