... compositions were categorized into three units: a mafic unit with SiO2 (48.36 wt Al2O3 (19.59 wt and Na2O + K2O (10.56 wt an intermediate unit with SiO2 (57.96 wt Al2O3 (19.11 wt and Na2O + K2O (5.74 wt and a felsic unit with SiO2 (64.47 73.39 wt Al2O3 (1.03 6.36 wt and Na2O + K2O (4.69 10.62 wt%; Hou et al...

... for grain size (Lupker et al., 2011). On the Tibetan Plateau, sediments show distinct intersectoral variations in Na2O/SiO2, K2O/ SiO2, and Fe2O3/SiO2 molar ratios (Figs. 4A, 4C, and 4E). The weak correlation between Na2O/ SiO2 and Al2O3/SiO2 molar ratios indicates an insignificant grain size control...

... diagenetic minerals (pistomesite: PI, apatite: AP, and calcite: CC; FeO, MgO, CaO, MnO, CO2, & P2O5) occur in the material transfers involving clastic minerals (quartz: QZ, albite: AB, K-feldspar: KS, and illite: IL; SiO2, Al2O3, Na2O, & K2O; Equation 20; Stanley 2025; Korsch et al. 1993). As a result...

... 78.96 wt%) and (K2O + Na2O)/CaO ratios (16.08 26.22), which are indicative of significant fractional crystallization. In Harker diagrams (Fig. 6), decreasing trends of Al2O3, FeOT, CaO, Na2O, and MgO with increasing SiO2, along with the pronounced depletion of Ba, Nb, Sr, P, Ti, and Eu in the trace...

...) and BHVO-2G (basaltic glass) were measured along with the 135 samples to evaluate the data quality. Repeated analyses of BHVO-2G indicated the 136 precisions for SiO2, TiO2, Al2O3, FeO, MnO, MgO, and CaO were better than ±1.3% 137 (2SD), and for Cr2O3, Na2O, K2O, and P2O5 were better than ±5% (2SD...

... + K2O)] values of these AB CD Figure 7. Diagrams of (A) Na2O + K2O versus SiO2 (after Irvine and Baragar, 1971); (B) SiO2 versus Zr/(TiO2 × 104) (after Winchester and Floyd, 1977); (C) A/NK [molar ratio Al2O3/(Na2O + K2O)] versus A/CNK [molar ratio Al2O3/(CaO + Na2O + K2O)] (after Maniar and Piccoli...

.... They show high SiO2 (70.61 74.29 wt%) and K2O + Na2O (5.17 7.52 wt moderate Al2O3 (11.77 15.97 wt and relatively low Fe2O3t (1.55 4.08 wt%) and TiO2 (0.13 0.69 wt%) contents. In the SiO2-versus-K2O + Na2O classification diagram, the samples mostly plot in the granite field (Fig. 9A). In addition, they have...

... of rapidly decreasing Sr and Ba with increasing Rb and little change in SiO2, Al2O3, Na2O and K2O in the course of fractionation have been documented, for example, in the granites of the Lachlan Fold Belt in eastern Australia, and are considered to be characteristic of evolved granites crystallizing K...

... sensitive high-resolution ion microprobe; MSWD mean square of weighted deviates. AB Figure 5. Plots of (A) K2O + Na2O versus SiO2 and (B) A/NK (molar Al2O3/[Na2O + K2O]) versus A/CNK (molarAl2O3/[CaO + Na2O + K2O]) for Late Triassic mafic intermediate rocks from the Fanshan complex, North China Craton...

... (0.49 0.67 wt Na2O (3.23 3.84 wt and K2O (6.42 6.67 wt%) contents. The P2O5 contents of the monzogranite are in the range of 0.04 0.08 wt%, lower than average P2O5 contents for granites with similar SiO2 and Al2O3 contents from regional regolithhosted LREE deposits (Figs. 8A and 8B). The monzogranite...

... change toward shoshonitic compositions with time. Trace element chemistry In Fig. 7, general fractionation trends are displayed on Harker variation diagrams of selected compatible and x x x x xxxx x x xx xx xx xxx xx x x xxxx x xxx x x x x xx xxxxxx x x Fig. 4. Na2O+K2O versus SiO2 plot for volcanic...

.... In average, pfaffenbergite from PF5-1 contains 59.03 wt% SiO2, 245 25.22 Al2O3 and 6.26 wt% CaO, 5.18 wt% Na2O and 3.36 wt% K2O, whereas in PF5-2 the SiO2 246 is higher, 66.76 wt%, Na2O slightly higher with 4.73 wt% and Al2O3, CaO and K2O lower, i.e., 247 21.54 wt%, 2.52 wt% and 3.02 wt% respectively. After...

... the granulite gneisses which may represent (meta)- cumulates crystallized from relatively highly evolved melts. Silica shows a steady increase from c. 41 60% as MgO decreases from c. 4.5 to 1.8%. There is a generalized concomi- tant increase in Al2O3, Na2O and K2O and decrease in Fe2O3*, TiO2 and (less clearly...

... examined petrographically, and studied using X-ray diffraction, size fraction segregation, and lithogeochemical analysis (Korsch et al. 1993; Stanley 1997). Ten major oxide concentrations (SiO2, TiO2, Al2O3, Fe2O3T, MnO, MgO, CaO, Na2O, K2O, P2O5) were determined by fusion-XRF analysis. Loss on ignition...

... versus other parameters/elements. Classification schemes using alkalies, such as the (Na2O+K2O) vs. SiO2 (TAS) diagram ( Le Maitre et al 1989 ), result in clear separation of the two metabasite groups (Figure 4 ). All mafic granulites are classified as subalkaline basalts (except one sample...

... saturation index (ASI) ranging from 1.10 to 1.28 (Fig. 4C). They plot within the S-type granite field in the ACF (A = Al2O3-Na2O-K2O; C = CaO; F = TFeO + MgO; Chappell and White, 1992) diagram (Fig. 4D). In the Harker diagram, TiO2, Al2O3, TFeO, MgO, and CaO display negative linear correlations with SiO2...

... and fall into the high-K calc-alkaline field on the SiO2-versus-K2O diagram (Fig. 5B). The aluminum saturation index (ASI = molar Al2O3/(CaO + Na2O + K2O) values range from 0.98 to 1.03 (<1.1), and indicate a metaluminous composition. Discrimination diagrams further suggest that the granodiorites...

... SiO2 TiO2 Al2O3 FeO MnO MgO CaO Na2O K2O NiO Total North South dykes Orthopyroxenes NEF21 52.34 0.11 2.28 10.65 0.20 28.88 1.71 0.08 0.06 96.31 NEF21 54.06 0.18 2.04 11.72 0.24 26.54 2.24 0.26 0.12 97.40 NEF21 53.68 0.11 1.02 11.99 0.26 28.44 2.13 0.05 0.04 97.72 NEF21 53.06 0.20 2.03 12.15 0.26 27.66...

.... The Perple_X program (version 6.9.1) was used to carry out these computations (Connolly, 2005 and Connolly, 2009 ). The model system, MnNCKFMASHTO (MnO-Na2O–CaO–K2O–FeO–MgO–Al2O3–SiO2–H2O–TiO2–Fe2O3), was used to address the complexities of the system under study. Based on the observed mineral assemblage...