SUMMARY The Semail Ophiolite in eastern Arabia is the largest and best-exposed slice of oceanic lithosphere on land. Detailed knowledge tectonic evolution shallow crust, particular during after ophiolite obduction Late Cretaceous times contrasted by few constraints physical compositional properties middle lower continental crust below obducted units. role inherited, pre-obduction crustal archit...

The early Paleozoic Terskey Suture zone, located in the southern part of Northern Tien Shan domain Kyrgyzstan, comprises tectonic slivers dismembered ophiolites and associated primitive volcanics deep-marine sediments. In Lake Songkul area, early-middle Cambrian pillow basalts are crosscut by Songkultau intrusion coarse-grained gneissose quartz diorites tonalites with geochemical characteristic...

19 Detrital-zircon analysis of sandstones interbedded with ca 464 Ma ignimbrites in 20 the lower Mweelrea Formation of the South Mayo Trough, western Ireland, 21 suggests Ordovician source-rock provenance that corresponds to two distinct 22 volcanic-arc phases on the Laurentian margin. East-derived sandstones contain a 23 suite of zircons with a mean age of ca 487 Ma that suggests derivation fr...

The compatibility of vanadium (V) during mantle melting is a function of oxygen fugacity (fO2): at high fO2’s, V becomes more incompatible. The prospects and limitations of using the V content of peridotites as a proxy for paleo-fO2 at the time of melt extraction were investigated here by assessing the uncertainties in V measurements and the sensitivity of V as a function of degree of melt extr...

Mineral Compositions in Xenoliths from Malaita The report by Collerson et al. (1) of transition zone and lower mantle phases in mantle-derived material from alnöite pipes on Malaita, Solomon Islands, is highly significant in view of the rarity of such natural assemblages. Malaita is part of the obducted southern margin of the Ontong Java Plateau, an area of overthickened oceanic crust (2–7) tha...

7 The Unst Ophiolite is the best exposed of a chain of early Ordovician ophiolites in the 8 Scottish Caledonides and is widely regarded as having formed in a supra-subduction zone 9 setting within the Iapetus Ocean. Reinterpretation of sheeted dykes suggests that it formed 10 as an oceanic core complex, presumably during subduction roll-back immediately prior to 11 obduction onto the Laurentian...

Melt extraction from the Earth’s mantle requires some form of channelized flow to produce the observed disequilibrium between the crust-forming lavas and their mantle sources. In this review, we discuss the influence of deformation on melt-extraction processes, with an emphasis on the understanding gained from a wide range of laboratory experimental investigations. Rheological properties of par...

The Dinarides, together with the Albanides and Hellenides, preserve stratigraphic successions derived from eastern margin of Adriatic microplate remnants ophiolites obducted Maliac-Vardar branch Neotethys Ocean. main stages in Mesozoic geodynamic history are: 1) rifting leading to opening Maliac Ocean Late Anisian, 2) onset an east-dipping intra-oceanic subduction Early-Middle Jurassic sea-floo...