3.3 Calcium isotopic composition of Central American volcanic arc mag...Figure 3.4 Ba/Th‐87Sr/86Sr (a), 143Nd/144Nd‐87Sr/86Sr (b), and 206Pb/204Pb‐8...4 Chapter 4Figure 4.1 Physiographic map of southwest North America. Locations of < 40 M...Figure 4.2 Smoothed 2D histogram of Nd and Sr initial isotopic compositions ...Figure 4.3 N‐MORB normalized trace element abundances from Sliderock Mountai...Figure 4.4 Ta/Th and εNd (T) vs. wt% SiO2 for < 55 wt% SiO2 volcanic rocks a...Figure 4.5 Spatial distribution of εNd(T) values for < 40 Ma basaltic volcan...Figure 4.6 Initial εNd vs. wt% P205/wt% K20 for Cenozoic basalts as 2D smoot...Figure 4.7 Initial εNd vs. (Zn/Fe) *1000 for mafic volcanic rocks (wt% MgO ≥...Figure 4.8 Initial εHf vs εNd values for Cenozoic basalts and peridotite xen...Figure 4.9 (a) Measured 187Os/188Os vs. whole rock wt% Al2O3 for peridotite ...Figure 4.10 176Hf/177Hf vs. 176Lu/177Hf for whole rock and clinopyroxenes fr...Figure 4.11 Measured εNd values vs.147Sm/144Nd for spinel and garnet peridot...Figure 4.12 Relative probability histograms (left axis) and cumulative proba...Figure 4.13 εNd(T) vs. whole rock Ta/Th for <40 Ma basaltic rocks. The 2D hi...Figure 4.14 Initial 87Sr/86Sr vs. Ta/Th for basaltic rocks with wt% SiO2 ≤ 5...Figure 4.15 Initial 208Pb/204Pb (a) and 207Pb/204Pb (b) vs. 206Pb/204Pb for ...Figure 4.16 208Pb/204Pb (a) and 207Pb/204Pb (b) vs. 206Pb/204Pb for high Ta/...Figure 4.17 Ta (ppm) vs. Th (ppm) (a) and (b) εNd (T) vs Ta (ppm) for asthen...Figure 4.18 Wt % P2O5/ wt% K2O (P/K) vs. 87Sr/86Sr (T) for Late Cretaceous S...Figure 4.19 Spatial variations in Nd isotopic compositions of ≥ 20 Ma (a) an...Figure 4.20 Distribution of intermediate and low Ta/Th group volcanic rocks ...Figure 4.21 εNd (T) (a), 87Sr/86Sr (T) (b), and Ta/Th (c) vs. eruptive age f...Figure 4.22 Cartoons depicting physical settings leading to volcanism of var...
5 Chapter 5Figure 5.1 Generalized geologic map of Ecuador showing the major geologic an...Figure 5.2 Geologic map of the Chalupas caldera assembled from field observa...Figure 5.3 Stratigraphic column based on exposures in Naxiche Gorge showing ...Figure 5.4 SiO2 variation diagrams for the Chalupas lavas. The high‐AhO3, hi...Figure 5.5 NMORB‐normalized trace element concentrations for representative ...Figure 5.6 Sr‐, Nd‐, and O‐isotope ratios of Chalupas whole rock samples plo...Figure 5.7 Sr‐, Nd‐, and O‐isotope ratios of metamorphic basement samples. A...Figure 5.8 Results of two‐stage finite difference‐AFC modeling of isotopic e...Figure 5.9 Comparison of measured concentrations of Rb, Th, Nb, and K versus...Figure 5.10 Nd isotopic data plotted versus latitude for Andean volcanic roc...Figure 5.11 Variation of melt density with depth compared to crustal density...Figure 5.12 Comparison of estimated magma supply rates for Chalupas, Cotopax...Figure 5.13 Groundmass (a), plagioclase (b), and biotite (c) 40Ar/39Ar incre...Figure 5.14 Major element trends in Chalupas lavas and tuffs.Figure 5.15 Schematic two‐stage AFC/FC model for the lavas and tuffs of the ...Figure 5.16 Effects of assimilation on the relationship between SiO2 concent...Figure 5.17 Model estimates of the magma supply (QAFC of Fig. 5.15) needed t...
6 Chapter 6Figure 6.1 Cone locations based on maps from Fodor et al. (1997), Fodor (200...Figure 6.2 Primitive mantle‐normalized REE abundances in clinopyroxene from ...Figure 6.3 Comparison of 208Pb/207Pb variations in Mauna Kea xenoliths with ...Figure 6.4 Comparison of Sr‐Pb and Nd‐Pb isotope variations in Mauna Kea xen...Figure 6.5 Comparison of δ18O values of clinopyroxene and olivine from the s...Figure 6.6 Comparison of Sr‐ and O‐isotope compositional variations in Mauna...Figure 6.7 Correlation between mineral Mg# and δ18O values in Mauna Kea xeno...Figure 6.8 MgO‐CaO trends in Mauna Kea glasses and wholerocks suggest olivin...Figure 6.9 Distribution of forsterite content in olivine phenocrysts from sh...Figure 6.10 Comparison of observed major element correlations in Mauna Kea b...
7 Chapter 7Figure 7.1 Simplified volcano‐tectonic map of Mt. Etna volcanowith the l...Figure 7.2 Correlation between the (220Rn/222Rn) and CO2 efflux in the sampl...Figure 7.3 Location of sites for the measurement of soil CO2 efflux, soil ra...Figure 7.4 Correlations between (222Rn) “activity” and CO2 efflux in the sam...Figure 7.5 Correlations between (220Rn) “activity” and CO2 efflux in the sam...Figure 7.6 Correlation plot between the log values of (220Rn/222Rn) and the ...Figure 7.7 Schematic of closed system ingrowth model of (220Rn) and (222Rn) ...Figure 7.8 Temporal patterns of the average SGDI values calculated for each ...Figure 7.9 Temporal patterns of the average SGDI values calculated for each ...Figure 7.10 – Left plots: Temporal variation of interpolated SGDI values, be...Figure 7.11 Temporal variation of interpolated SGDI values, before and after...Figure 7.12 Simulations of the possible temporal patterns of SGDI values (ye...Figure 7.13 Dendrograms showing the results of cluster analysis on the SGDI ...Figure 7.14 Spectrograms of frequencies for the SGDI time series in each of ...Figure 7.15 Spectrograms of frequencies for the SGDI time series in each of ...Figure 7.16 Normal probability plots for the SGDI data of the four clusters ...Figure 7.17 Normal probability plots for the SGDI data of the three clusters...
8 Chapter 8Figure 8.1 Variations in forg and atmospheric pO2 over Earth history as infe...Figure 8.2 Carbon cycle parameters consistent with a steady state seawater δFigure 8.3 Variation in the δ13C of seawater and primary marine carbonates (...
9 Chapter 9Figure 9.1 Comparison of Detrital Mineral Geochronometers. Garnet provides g...Figure 9.2 Predicted Age Precision as a Function of Starting Grain Diameter....Figure 9.3 Nd Sample‐to‐Blank Ratio vs. Grain Diameter. These predictions of...Figure 9.4 Conceptual workflow showing the major methodological steps for de...Figure 9.5 Ternary diagrams showing garnet chemistry as measured using a tab...Figure 9.6 Hampton Beach (NH) Detrital Garnet Isochrons. Two‐point isochrons...Figure 9.7 Townshend Dam (VT) Garnet Isochrons. (a) shows two‐point isochron...Figure 9.8 Predicted vs. Actual Age Precision on Single Detrital Grains. Rea...Figure 9.9 Scottish Southern Uplands Terrane Detrital Garnet Isochrons. Two ...
10 Chapter 10Figure 10.1 δ53Cr of aqueous Cr(VI) in a Cr‐contaminated shallow aquifer tha...Figure 10.2 δ53Cr of aqueous Cr(VI) in the Snake River Plain aquiferδ53C...Figure 10.3 Concentration (circles) and δ238U (squares) of aqueous U(VI) in ...Figure 10.4 δ238U vs inverse of dissolved U concentration during an oxidatio...Figure 10.5 Se(VI) concentration and isotopic composition in a simple model ...Figure 10.6 Rayleigh models for the δ238U data shown in Fig. 10.3, for aceta...Figure 10.7 Aqueous Cr(VI) concentrations and δ53Cr reported by Berna et al....
11 Chapter 11Figure 11.1 Schematic of the two prevalent sulfur species, oxidized sulfate ...Figure 11.2 (a) an example of classic Rayleigh distillation between reactant...Figure 11.3 (a) Sulfur isotope fractionation factor between reactant sulfate...Figure 11.4 A compilation of four experimental datasets of pure cultures gro...Figure 11.5 Four sets of 30 cm push cores from a salt marsh in the North Nor...Figure 11.6 (a) Measured sulfate (open circles) and sulfide (filled diamonds...Figure 11.7 Dissolved sulfate (blue) and associated δ34S (red) as a function...
12 Chapter 12Figure 12.1 The base case simulation of sulfate reduction across a one‐dimen...Figure 12.2 The reactive transport model implemented in Section 12.2.1 now a...Figure 12.3 Relationships between reaction progress (f) and isotope ratio fo...Figure 12.4 The reactive transport model implemented in Section 12.2.1 now a...Figure 12.5 The reactive transport model implemented in Section 12.2.1 now a...Figure 12.6 Relationships between reaction progress (f) and isotope ratio fo...Figure 12.7 Summary of cross‐plot
