O are claimed to be pieces of ocean crust and upper mantle that have been thrust up onto continental crust and are now found in mountains, mainly along continental margins.1,2 An ideal ophiolite suite consists from bottom to top of peridotite, gabbro, sheeted dikes, basalt with pillow lavas and sedimentary rocks. The peridotite is considered to be an upper mantle rock, while the remainder of th...

Before its collision with Eurasia1–5, the Indian Plate moved rapidly, at rates exceeding 140mmyr−1 for a period of 20 million years1,3–7. This motion is 50 to 100% faster than the maximum sustained rate of convergence of themain tectonic plates today8. The cause of such high rates of convergence is unclear and not reproduced by numerical models9,10. Here we show that existing geological data11,...

Geological, petrological, and axygcn isotopic data are pn:sentecl for 228 whole rock and mineral samples collected from a 100x20 km area of the nortbem Samail opbiolite in Oman. MOlt of these samples arc from three detailed profiles tluough the pillow IIIYBI, sbeetecl dikes, and .red pbbi'OI of this laterally heterogeneous fratpnent of Cretaceous oceanic crust, down to and 8C1'0I& the petroaop:...

Analysis of spatial, temporal, geological and geochemical patterns of ophiolites in the Indonesian and New Guinea region indicates a strong correlation with marginal basin development and closure. The spatial distribution of ophiolites is mostly linked with marginal basin producing zones of oblique convergence and collision. Strain partitioning in these zones creates a series of ephemeral plate...

We consider the mixing behaviour of the solutions of the continuity equation associated with a divergence-free velocity field. In this announcement we sketch two explicit examples of exponential decay of the mixing scale of the solution, in case of Sobolev velocity fields, thus showing the optimality of known lower bounds. We also describe how to use such examples to construct solutions to the ...

manganese ore deposits occurred in various types of syngenetic, diagenetic and epigenetic mineralization in association with radiolarian cherts in colored melange of neyriz ophiolite in abadeh tashk area, eastern fars province. microscopic study and xrd analyses show a simple mineralogy for manganese compounds in all types. psylomelane and braunite are the primary manganese compounds in syngene...

RÉSUMÉ Expérimentation in situ Sédiment littoral Magali GERINO, Georges STORA and Jean-Pierre DURBEC Centre d'Océanologie de Marseille, URA 41, Station Marine d'Endoume, rue de la Batterie des Lions, 13007 Marseille, France. Received 10/02/94, in revised form 5/09/94, accepted 13/09/94 An in situ experiment was conducted over a short period of time to quantify bioturbation with a pulse input of...