Enrichment-depletion diagrams

Enrichment-depletion diagrams are also useful as a way of displaying element mobility this has been used particularly in alteration zones associated with hydrothermal mineralization. For example, Taylor and Fryer (1980) show the relative mobilities of trace and major elements in the zones of potassic and propylitic alteration associated with a porphyry copper deposit. In this case the enrichment/depletion is measured relative to the unaltered country rock. 

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At least three of the studied blends [16,145] h86 (N86=1520)/d75 (N75=1625, deuteration extent e=0.4),d75/h66 (N66=2030) and h66/d52 (N52=1510 as well as e=0.34) may be described by a rather small Afs driving surface segregation. In an extreme case of the lowest Afs magnitude the enrichment-depletion effect is expected, as observed for the h66/d52 blend (see the next section). Here we characterize this class of mixtures with the results obtained for the h86/d75 blend. Surface excess z has been determined [145] as a function of bulk concentration at two different temperatures the corresponding (f) values are denoted as open circles (O) in the h86/d75 phase diagram (see inset to Fig. 21a). Surface segregation of the h86 component with a local concentration ( >(z) has been stud-... 

Marker diagrams show depletions in Al, Ca, Ti, Fe, Mn, Mg, and P with Si02 enrichment indicative of fractionation of phenocryst phases noted above. However, major elements plotted as a function of MgO display linear trends that... 

In general, the decrease in opacity obtained with the lower abundances characteristic of the LMC tends to help to confine the evolutionary tracks to the blue side of the H-R Diagram. However, most models are computed with the an abundance set taken as solar divided by, say, four. In practice, the LMC abundance distribution is not this simple.Dopita (1986) and Russell, Bessell and Dopita have shown that, in the LMC, the underabundance of various elements with respect to solar is dependent upon their atomic number. For example, Cand N are depleted by about 0.8 dex, O and Ne by about 0.5 dex, Ca by anbout 0.3 dex and the heavy elements from Ti through Fe to Ba by about 0.2 dex. This pattern is similar to that produced in models of deflagration supemovae, and may indicate that these have been relatively more important in enriching the interstellar medium in the LMC. 

Figure 3 Crust-mantle differentiation patterns for the decay systems Rb-Sr, Sm-Nd, Lu-Hf, and Re-Os. The diagram illustrates the depletion-enrichment relationships of the parent-daughter pairs, which lead to the isotopic differences between continental crust and the residual mantle. For example, the Sm/Nd ratio is increased, whereas the Rb/Sr ratio is decreased in the residual mantle. This leads to the isotopic correlation in mantle-derived rocks plotted in Figure 4(a). The construction is similar to that used in Figure 2, but D values have been adjusted slightly for greater clarity.

Figure 18 Extended trace-element diagrams (hereafter, spidergrams) for volcanics and felsic plutonic rocks from the Talkeetna arc section, south central Alaska. Concentrations are normalized to N-MORB (Hofmann, 1988). Bold red lines are average values from Table 3. Talkeetna lavas, and plutonic rocks interpreted as hquid compositions, are only shghtly enriched in light REE compared to MORB, but show depletion of Nb and Ta, and enrichment of Pb and Sr, t)fpical for arc lavas worldwide. Their trace-element contents are similar to, for example, lavas from the modem Tonga arc. Data from Greene et al. (2003) and our unpublished research.

Ethanol, with a boiling point of 78.3°C, has a vapor pressure of 760 mmHg at this temperature and consequently forms a higher mole fraction in the vapor space above a heated ethanol/water mixture than it does in the liquid phase. Condensation of the alcohol-enriched vapor mixture obtained in this way produces a solution of ethanol in water again, but now enriched in the concentration of ethanol. In a laboratory batch distillation the process described above may be carried out very easily, but this only achieves a limited (by the liquid-vapor composition diagram) improvement in concentration of ethanol obtained with each repetition of the distillation (Eig. 16.5a). Also, as the distillation proceeds, the concentration of alcohol in the distilling vessel becomes depleted. Consequently there is also a gradual depletion in the alcohol concentration obtained in the vapor, and the condensate from this. Despite these problems, many small distilleries still use batch distillation to raise the alcohol concentrations to the requirement of their product [44]. 

Fig.24.a-b Typical d52 volume fraction (1—<))) vs depth z profiles indicating a a depletion b an enrichment in the h66 component, obtained for 90%h66/10%d52 and 30%h66/70%d52 monolayers annealed at 71 °C for 16 and 43 h, respectively [175]. Hatched areas mark positive (b) and negative (a) values of the h66 surface excess z. The free surface locus (z=0) is yielded by - the profile itself (a) - a profile of the control layer measured prior to the annealed sample (as in Fig. 21 a) - the interface created by a reference layer positioned on top of the annealed sample (b) c a phase diagram as outlined by previously determined coexistence compositions [91] (solid line described by %=(0.452/T-1.2Xl(T4)(l+0.031)) and coexistence temperatures [138] (X points). Bulk compositions in one phase region are marked where the surface enrichment (A symbols) or depletion ( points) in h66 is concluded... 

FIGURE 3.29 eH time diagrams for the evolution of the Earth s mantle, (a) The mantle evolution curve of Vervoort and Blichert-Toft (1999) showing pre-3.0 Ga fractionation followed by a less extreme fractionation event. The mantle curve indicates that the mantle was depleted in Lu relative to Hf. Negative eHf-values would imply derivation from an enriched source such as enriched mantle or ancient continental crust, (b) A proposed eH -mantle evolution curve based upon eH -values calculated using the fast decay sheme of Bizzarre et al. (2003) - A = 1.983 X 10-11. This dataset supports the mantle evolution curve proposed by Vervoort and Blichert-Toft (1999) shown in (a). The data are taken from Blichert-Toft and Arndt (1999), Vervoort and Blichert-Toft (1999), Amelin et al. (1999), and Amelin et al. (2000). Symbols diamonds, most radiogenic samples Arc, modern arc samples ... 

Mg/Si and Al/Si ratio and CaO versus Al203 plots. These diagrams explore potential complementary relationships between the reservoirs assuming primitive mantle (PM) as a common starting composition. It should be noted that Archaean SCLM is enriched in Si relative to the modern depleted mantle and so lies below the present day depleted mantle (DM) trend. In contrast Proterozoic and Phanerozoic SCLM lie on the DM-trend. 

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