This study illustrates the field relationships of jadeitite-bearing block-in-matrix sequences on Syros and Tinos, Cycladic Blueschist Unit, and adds additional U–Pb zircon ages for jadeitites to the geochronological database. The results confirm the importance of Cretaceous (c. 80 Ma) and Eocene (c. 50 Ma) processes in their geological evolution. Interpretations suggesting that the jadeitites were formed by complete metasomatic replacement of a pre-existing rock are not fully supported by field observations. In at least some cases, the formation of jadeitite is likely due to precipitation from Na-Al-Si-rich aqueous fluids, which also caused variable metasomatic alteration of the host rock. Unambiguous age constraints for formation of the Syros and Tinos jadeitites are not available. A relationship to Eocene blueschist facies metamorphism recorded in the associated metamafic rocks seems plausible. However, since high-pressure overprinting of pre-Eocene jadeitite is also conceivable, there is a much larger time window for jadeitite formation, framed by Cretaceous (c. 80–76 Ma) protolith ages of various mélange blocks and the waning stages of blueschist facies metamorphism (c. 40 Ma). Field observations are consistent with the interpretation that the mélange-like occurrences on Syros and Tinos record, to varying extent, multi-stage processes that include detachment of mafic rocks from the subducting plate, local infiltration of Na-Al-Si-rich aqueous fluids, exhumation via a serpentinitic matrix in a subduction channel and reworking of the primary block-in-matrix fabric by sedimentary or tectonic processes during accretionary wedge formation.

A reconnaissance survey of part of western Cambodia has found quarries in and near the town of Pailin containing chert, basalt, volcaniclastic rocks, gabbro and serpentinite. Abandoned quarries contain chert and basalt clasts in a volcaniclastic matrix and may constitute a mélange. A new, recently active, quarry contains these rock units in close and coherent contact but they lack the serpentinitic matrix of the Thung Kabin Mélange of eastern Thailand. The rock units are in close contact and may best be described collectively as a dismembered ophiolite. The mélange–ophiolite association constitutes a 3 km wide, 20 km long E–W belt separating a northern 200 km2 block of the mainly amphibolitic Pailin Crystalline Complex from a southern area of Triassic submarine fan siliciclastic rocks. The cherts yield the first documented radiolarian fauna from Cambodia and include a moderately well-preserved Asselian–Sakmarian age fauna consisting of Pseudoalbaillella sakmarensis, Pseudoalbaillella scalprata morphotype scalprata, Pseudoalbaillella sp. cf. P. simplex, Pseudoalbaillella u-forma morphotype II, Pseudoalbaillella sp. cf. P. elegans, Pseudoalbaillella sp. cf. P. lomentaria, Albaillella sp., Pseudoalbaillella spp., Trilonche? sp., Latentifistularia gen. et sp. indet. and Entactinaria gen. et sp. indet. The Pailin ophiolitic rocks, mélange and volcanic rocks occur within a generally E–W-trending belt, which suggests that the Sa Kaeo Suture does not extend southeastwards paralleling the Thai–Cambodian border, nor extend under the Cardamom Mountains but, rather, extends eastwards into Cambodia and possibly then turns southwards along the strike of the Pursat–Kampot Fold Belt.

Kinematic analysis of mélange fabrics provides critical information concerning tectonic processes and evaluation of the kinematics of ancient relative plate motion. Systematic kinematic analysis of deformed structures within a tectonic mélange exposed along the Zagros Suture Zone elucidates that this zone is an ancient transpressional boundary. The mélange is composed of a greywacke and mudstone matrix surrounding various lenses, blocks and ribbons of radiolarian chert, limestone, sandstone, pillow lava, tuff, serpentinite, shale and marl. The deformation fabrics of the mélange suggest that the mélange units were tectonically accreted at shallow levels within a subduction complex, resulting in layer-parallel extension and shearing along a NW–SE-trending suture that juxtaposes the Afro-Arabian continent to the south and the Central Iranian microcontinents to the north. The tectonic mélange is characterized by subhorizontal layer-parallel extension and subsequent heterogeneous non-coaxial shear resulting in alternating asymmetric and layer-parallel extensional fabrics such as P–Y fabrics and boudinaged layers. Kinematic data suggest that the mélange formed during oblique subduction of the Neo-Tethys oceanic lithosphere in Late Cretaceous time. Kinematic shear sense indicators reveal that the slip direction (N9°E to N14°E) during accretion-related deformations reflects the relative plate motion between the Afro-Arabian continent and Central Iranian microcontinents during Late Cretaceous to Miocene times.

Limestone megaclasts up to hundreds of metres in size are present within the Gwna Group mélange, North Wales, UK. The mélange has been interpreted as part of a Peri-Gondwanan fore-arc accretionary complex although the age of deposition remains contentious, proposals ranging from Neoproterozoic to Early Ordovician. This paper uses strontium isotope chemostratigraphy to establish the age of the limestone blocks and thus provide a maximum age constraint on mélange formation. Results show that, although the carbonates are locally dolomitized, primary 87Sr/86Sr ratios can be identified and indicate deposition sometime between the late Tonian and earliest Cryogenian. This age is older than that suggested by stromatolites within the limestone and indicates that the limestone did not form as cap carbonate deposits.

Passive control of the entrainment phenomenon in the turbulent jets is a mixing enhancement economical method of wide interest in the industrial field. A lobed nozzle without lobes inclinations allows improving mixing in the generated flow compared to a reference circular jet. A second lobed nozzle, having the same exit plane geometry but with inclined lobes intensifies, in a considerable manner, the entrainment which reaches up to four times the one in the reference circular jet. The lobed jets vortical dynamics analysis shows that the azimuthal structures are not annular like in the case of a circular jet, but discontinuous, due to the shear of the transverse flow induced by the curvature variation of the exit plane. The streamwise structures development at the discontinuities locations is probably explaining the entrainment benefit observed in the lobed jet without inclination angles. The lobed jet issued from the second nozzle presents like the first lobed jet, discontinuous azimuthal structures, but its remarkable induction benefit is not merely owed to the previous phenomenon. The intensification and organisation of the streamwise vorticity field into large scale structures, resulting in a consequent mixing enhancement, are connected to the increased shear produced by the lobes inclinations.

Scattered occurrences of ophiolitic rocks are widespread in the Cyclades islands of Greece and are important for understanding the later Mesozoic ocean spreading and collisional history of the region, which has been obscured by Cenozoic nappe stacking, metamorphism, plutonism and extension. Ophiolitic rocks in the Upper Tectonic Unit of Ikaria are preserved in a mélange underlying Triassic limestones in the Kefala Unit and in a coarse-grained conglomerate at Faros directly overlying the mid-crustal detachment fault. The geochemistry of these rocks has been determined, their mineralogy investigated by electron microprobe, and K–Ar radiometric dating was carried out. Sole rocks are amphibolite of alkaline basalt protolith. Most ophiolitic samples from Ikaria consist of hornblende gabbro with MORB geochemistry that underwent sea-floor hydration, deformation and metamorphism. The large variation in degree of deformation, grade of metamorphism, and radiometric ages suggest syn-spreading extensional deformation at a slow-spreading ridge. The ophiolitic mélange on Ikaria, because it is unaffected by younger metamorphism, provides clear evidence for Late Cretaceous ocean-crust formation in the Cyclades region.

The Ballantrae complex has yielded its oldest yet determined age of 576 ± 32 Ma from an Sm–Nd internal isochron for a block ‘eclogite’ interpreted as being a component of the mélange-olistostrome unit at Knockormal. This unit is possibly older than the main ophiolitic part of the complex and the ‘eclogite’ block provides evidence for the existence of oceanic crust older than c. 575 Ma on the southern margin of the Laurentian shield.

An Sm–Nd internal isochron from a high-grade metapyroxenite in the metamorphic aureole beneath an obducted slab of mantle peridotite at Laigh Knocklaugh yields an age of 505 ± 11 Ma. This is interpreted as close to the age of metamorphism and is older than the K–Ar age of 478 ± 8 Ma determined for the amphibolites of the aureole which underlie the metapyroxenite. The metapyroxenite had a provenance deeper in the oceanic crust than the amphibolite and the former has been structurally detached and justaposed against the latter in this telescoped metamorphic sequence.