Ridge systems

Low-temperature circulation of seawater through mid-ocean ridge systems creates a deficiency in Mg and an excess in Ca at middepths (de Villiers and Nelson, 1999). 

Figure 2. (A)-(H) Equiline diagrams for areas of ridge from the global ridge system. Note that data from individual areas of ridge often form trends indicating a relationship between Th/U and ( °Th)/( U). The equihne diagram is an x-y plot with both axes normalized to ( Th). Therefore a likely explanation for the trends is that they reflect mixing of melts having distinct Th/U.

Advective transport through sediments, coastal aquifers, and submarine ridge systems. 

Discharge via Venting from Mid Ocean Ridge Systems... 

In the example above, a maximum point was found within the explored domain. This is, however, not often encountered. Most frequently, the response surface is either monotonous in the explored domain or describes saddle-shaped surfaces or ridge systems. In such cases, it is not easy to comprehend the shape of the response surface from the algebraic expression of the model. A transformation to... 

The rotation removes the cross-product terms from the original response surface model. This form of the canonical model is very useful for exploring ridge systems. Such systems occur when some eigenvalue is small due to a feeble curvature of the surface in the corresponding Z direction. The variation in this direction is therefore largely described by the corresponding linear coefficient 9,. 

Example Synthesis of 2-Trimethylsilyloxy-l,3-Butadiene. Exploration of a Rising Ridge System by Canonical Analysis... 

LREE/HREE ratios, a difference which is also apparent from cpx compositions (Rivalenti et al., 1996). The lanthanum concentrations are typically in the range 0.005-0.05 X chondrites. Based on their REE distribution in cpx (Figure 18), the abyssal peridotites from slow-spreading ridge systems ([Pg.831]

In summary, based upon the range of values reported for the different regions (MOR, OIB, arcs, and continents), the total rate of contemporary degassing of mantle-derived He lies in the range of 1,039-2,270 mol yr The oceanic ridge system dominates the flux with a contribution between 57% and 78 % of the total. 

The production of broadly granitic magmas from juvenile, mantle-derived materials is most easily demonstrated in oceanic settings remote from continental influences, for example, (i) the development of the volumetricaUy minor plagio-granites of mid-ocean ridge systems, now... 

A number of studies have used the major element (and trace element) systematics of MORE to constrain the mean extent and mean pressure of melting, as well as the depth and temperature of intersection of the mantle solidus, both for a given region and for the global ocean ridge system as a whole (e.g., Klein and Langmuir, 1987 ... 

Focations of known hydrothermal activity along the global mid-ocean ridge system = known active. sites = active sites indicated by midwater chemical anomalies... 

The area is covered by sedimentary rocks, mainly of Tertiary age. The valley lies between two parallel east-west ridge systems. Wheat and... 

---