Fast-spreading ridges

Niu Y. and Hekinian R. (1997a) Basaltic liquids and harzburgitic residues in the Garrett Transform a case study at fast-spreading ridges. Earth Planet. Sci. Lett. 146,... 

Figure 4 Decay of typical initial U-series excesses in MORE. Indication of age uncertainty for samples located within the axial neovolcanic zone for slow and fast spreading ridges indicated by double headed arrows (see text...

Constantin M. (1999) Gabbroic intrusions and magmatic metasomatism in harzburgites from the Garrett transform fault implications for the nature of the mantle-crust transition at fast spreading ridges. Contrib. Min. Petrol. 136, 111-130. 

Nicolas (1989) divided ophiolite complexes into two main types - the harzburgite type (e.g. Oman Bay of Islands, Newfoundland Zambales, Philippines) and the lherzolite type (e.g. Trinity, California Lanzo, Italy). He proposed that the harzburgite-type of ophiolite represents oceanic crust created at a fast spreading ridge and a mantle sequence which... 

Figure 6. Oxygen and hydrogen isotope values of end-member vent flnids. The seawater-basalt reaction vector indicates calculated fluid evolution to decreasing water/rock mass ratios (Shanks et al. 1995). Most of these data follow the reaction vector within AD error of 1.5%o. Exceptions are the Mid-Atlantic Ridge samples, which have quite high AD values, and very low-chloride samples from fast spreading ridges, which are influenced by phase separation or magmatic water (see text).

Mahoney JJ, Sinton JM, Kurz MD, Macdougall JD, Spencer KJ, Lugmair GW (1994) Isotope and trace element characteristics of a super-fast spreading ridge East Pacific Rise, 13-23°S. Earth Planet Sci Lett 121 173-193... 

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