GSA DATA REPOSITORY

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1 GSA DATA REPOSITORY Allan et al. SUPPLEMENTARY INFORMATION Summary of Magma Types Table DR1 summarizes some of the key petrologic, geochemical and physical characteristics of the three magma types (Oruanui biotite-free, biotite-bearing and NE Dome types) described in the manuscript. Analytical Techniques Pumice clasts were cleaned to remove any adhering matrix, soaked for 24 hours in distilled water and then oven dried at 110 C for 24 to 48 hours. If pumices were of sufficient size (> ~ 6 cm) they were split in half to use one fraction for bulk chemistry and the remaining split for crystal specific studies. Whole Rock Chemistry Sample splits for bulk analytical work were reduced to a fine powder in an agate Tema. The powders were then further split into aliquots for major and trace element characterization by X-Ray Fluorescence (XRF) and solution inductively coupled plasma mass spectrometry (ICP-MS) methods, respectively. XRF analyses were carried out by Spectrachem Analytical (CRL Energy LTD), Wellington, New Zealand. The powders were held at 1000 C for 1 hour and weighed to determine loss on ignition (LOI). Representative analyses from each of the three magma types discussed in the manuscript, as well as data for international rock standards (JR-1, rhyolite; BCR-2, basalt; BHVO-2, basalt) collected during the same sessions are reported in Table DR2. On the basis of repeat measurements of these rock standards we estimate the average relative precision (%2 sd = 2 sd/mean 100) of our XRF data is as follows; SiO 2, Al 2 O 3 and Fe 2 O 3 - <1%; MnO, MgO, CaO, Na 2 O and P 2 O 5 1-2%; K 2 O, TiO 2 and LOI 3-5%. Our measured values are in excellent agreement with the preferred values for these standards in the GeoReM online database ( All other analytical work was carried out at Victoria University of Wellington, New Zealand. The trace element compositions of single pumices were determined using an Agilent 7500CS ICP-MS and adopting 43 Ca as an internal standard with the CaO content of the samples having previously been determined to within ± 2% from XRF analyses (Table DR2). Sample and standard powders were digested using conventional HF + HNO 3 methods for which 50 drops of concentrated HF and 15 drops concentrated HNO 3 were added to 50 mg of powder, capped in 23 ml Savellex Teflon beakers and placed on a hotplate at 120 C for 48 hours. After this the caps to the beakers were removed and the sample-acid solution allowed to reduce to incipient dryness before two further stages of digestion took place in 6M HCl, 1

2 followed by concentrated HNO 3 before the final dissolution in 9 ml of 1M HNO 3. All acids were ultra high purity Optima acids. Representative analyses from the three magma types and data for international rock standards acquired during the same analytical sessions are reported in Table DR2. The average relative precision of our minor and trace element ICP-MS measurements, based on repeat analyses of the rock standards BCR-2, BHVO-2 and JR-1, are estimated to be as follows: MgO, TiO 2, Ga, Rb, Sr, Y, Zr, Nb, and La - < 3%; MnO, Ba, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Th and U 3-5%; Cu and Pb 5-10%; Sc, Mo and Cs 10-15%; Zn 15-20%; Cr > 20%. Our measured values are also in excellent agreement with the GeoReM preferred values for the BHVO-2 and BCR-2 standards (most elements within 1 to 4% of the preferred values; Table DR2). The trace element concentrations of the JR-1 standard are not well constrained so we report our preferred values for JR-1, which were compiled from the GeoReM database, in Table DR3 for reference. In Situ Analytical Techniques Sample splits allocated for crystal specific investigations were gently crushed using an agate mortar and pestle to liberate crystals which were then mounted in epoxy resin, polished and analyzed by electron probe microanalyzer (EPMA) and laser ablation (LA-) ICP-MS. Major element compositions were determined using a JEOL JXA-8230 EPMA equipped with 5 wavelength dispersive spectrometers. Plagioclase and amphibole analyses were conducted at 15 kv and 12 na under a focused (~1 μm) electron beam. Standardization of element oxide concentrations and count rates was achieved using the NMNH plagioclase, Engels amphibole, Kakanui Augite, OR-1 orthoclase and synthetic element oxides standards (MnO, MgO, TiO 2 ) and concentrations of the unknowns calculated using the ZAF correction method. Analyses of the NMNH plagioclase and Engels amphibole standards were interspersed among sample plagioclase and amphiboles to monitor, and if necessary, correct for spectrometer drift. During analysis of the rhyolitic glasses the current was reduced to 8 na and the electron beam defocused to microns in order to minimize alkali loss during EPMA. In addition, Na 2 O and K 2 O were measured during the first analytical scan (of 2) and with reduced count times (12 s for Na 2 O). Standardization for glass analyses was achieved using the Icelandic rhyolite glass standard ATHO-G (for SiO 2, Al 2 O 3, FeO, CaO, Na 2 O, K 2 O), the basaltic glass standard VGA-99 (for TiO 2 and MgO) and a synthetic MnO. Analyses of ATHO-G were interspersed among the unknowns to monitor, and if necessary, to correct for spectrometer drift. The mean compositions of glass fragments from individual clasts, as well as data for the ATHO-G standard, are reported in Table DR4. In situ trace element determinations of amphiboles in Oruanui and NE Dome clasts were determined using a New Wave 193 nm (deep UV) solid state laser ablation system coupled to the Agilent 7500CS ICP-MS. The isotope 43 Ca was employed as an internal standard with the concentration of CaO in the amphibole having been previously measured by EPMA. Calculation of trace element concentrations also requires accompanying analyses of a well characterized and preferably matrix matched reference material (i.e. the calibration standard). Because there is no widely available, well characterized amphibole trace element 2

3 standard we used the basaltic glass BHVO-2G as our calibration standard, which has a major element composition similar to that of amphibole. The BHVO-2G concentration values used for normalization were the preferred values in the online GeoReM database in July Tuning and optimization of signal sensitivity and stability was achieved by rastering across the BHVO-2G standard and adjusting the inflow of ultra pure He gas. Data were acquired using 60 s acquisitions (+ 60 s backgrounds) under a static, circular laser beam of 35 μm diameter pulsed at 5 Hz. Data were reduced using the Iolite software package using the trace element (Internal Standard) data reduction scheme. The time resolved signal for each analysis was examined to remove any data compromised by the accidental ablation of inclusions beneath the polished surface. The major and trace element data and temperature, pressure, oxygen fugacity and H 2 O melt estimates from representative amphibole crystals are presented in Table DR5. 3

4 Table DR1. Summary of the characteristics of the biotite-free and biotite-bearing Oruanui magmas and biotite-bearing rhyolite lava from the NE Dome system to the northeast of Taupo volcano Magma/pumice Oruanui (bt-free) Oruanui (bt-bearing) NE Dome-type type WR SiO 2 (wt %) Crystallinity 6-13% 10-20% 12-24% Phases pl, qtz, opx, hbl, mt, ilm, ap pl, qtz, bt, hbl, opx, mt, ilm ± cum pl, qtz, bt, hbl, opx, mt, ilm Temperature C C C Pressure MPa MPa MPa Plagioclase rims An An An Matrix glass shards Unimodal, moderate K 2O (with higher FeO, CaO, TiO 2 and MgO) Glass populations from single pumices are either unimodal high K 2O, bimodal with both high and moderate K 2O groups, or form a spectrum between the two groups Unimodal, high K 2O (with lower FeO, CaO, TiO 2 and MgO) Mineral phases presented in order of relative abundance. pl - plagioclase, qtz - quartz, opx - orthopyroxene, hbl - hornblende, bt - biotite, cum - cummingtonite, mt - magnetite, il - ilmenite, ap - apatite. Temperatures reported are the inferred final magmatic temperatures estimated from Fe-Ti oxide equilibrium pairs and modal temperatures from amphibole geothermometry (Ridolfi et al., 2010). Pressure estimates are from amphibole geobarometry (using Ridolfi et al., 2010 formulations) with additional constraints for the bt-free Oruanui from volatile entrapment pressures from quartz melt inclusions (from Liu et al., 2006). Data from this study with additional constraints for the NE Dome magmas from Sutton et al. (1995). 4

5 Table DR2. Major and trace element chemistry of single pumice clasts and rock standards as determined by XRF and ICP-MS. XRF analyses determined by Spectrachem Analytical (CRL Energy LTD), Wellington, New Zealand ICP-MS analyses determined at Victoria University of Wellington using an Agilent 7500CS ICP-MS n.a - not analysed. XRF data are reported as wt% and ICP-MS data as ppm unless stated otherwise Oruanui biotite-free pumices (volumetrically dominant) Oruanui biotite-bearing pumices NE Dome lava samples Data for rock powder standards measured during the same sessions Eruptive phase phase 1 phase 1 phase 1 phase 1 phase 2 phase 2 phase 2 phase 1 phase 1 phase 1 phase 2 phase 2 phase 1 phase 1 phase 1 phase 1 phase 2 RTD RTD Trig9471 JR-1 rhyolite standard BCR-2 (USGS - Columbia River Basalt) BHVO-2 (Hawaiian Basalt) Sample number P1960 P P P1959 P P P P P P P P P1639 P1972 P P P R559_AA1 R559_AA2 R828-1 XRF (normalized to anhydrous totals) Mean (3) 2 sd Preferred % difference % 2 sd precision Mean (2) 2 sd Preferred % difference % 2 sd precision n = 1 2 sd Preferred % difference % 2 sd precision Average % 2 sd precision SiO SiO 2 (wt%) 1.0 TiO TiO Al2O Al 2O Fe2O Fe 2O MnO MnO 1.1 MgO MgO 1.1 CaO CaO 1.9 Na 2O Na 2O 1.9 K2O K 2O 3.5 P2O P 2O SUM LOI LOI 3.9 Original total Average % 2sd precision based on analysis of whole rock standards < 1% - SiO 2, Al 2O 3, Fe 2O 3 1 to 2% - MnO, MgO, CaO, Na 2O, P 2O 5 3 to 5% - K 2O, TiO 2, LOI JR-1 - ICP-MS trace element data BCR-2 - ICP-MS trace element data BHVO-2 - ICP-MS trace element data Solution ICP-MS Mean (7) 2 sd Preferred % difference % 2 sd precision Mean (8) 2 sd Preferred % difference % 2 sd precision Mean (4) 2 sd Preferred % difference % 2 sd precision Average % 2 sd precision MgO (wt %) MgO (wt %) 2.2 Average % 2sd precision based on analysis Sc Sc (ppm) 13 of whole rock standards Ti Ti 2.8 < 3% - MgO, TiO2, V, Ga, Rb, Sr, Y, Zr, Nb, V V 2.9 La Cr Cr 31 3 to 5% - MnO, Ba, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Th, U MnO MnO Cu Cu to 10% - Cu, Pb Zn Zn to 15% - Sc, Mo, Cs Ga Ga to 20% - Zn Rb Rb Sr Sr Y Y Zr Zr Nb n.a n.a n.a Nb Mo Mo Cs Cs Ba Ba La La Ce Ce Pr Pr Nd Nd Sm Sm Eu Eu Gd Gd Tb Tb Dy Dy Ho Ho Er Er Tm Tm Yb Yb Lu Lu Hf Hf Pb Pb Th Th U U

6 Table DR3. Our preferred values for JR-1 rhyolite standard based on data compiled from the GeoReM database (accessed November 2010) Major element oxide values stated reported as wt% and trace elements reported as ppm unless stated otherwise. 2 sd of compiled values Precision of the preferred values (% 2 sd) Precision of values measured in this study (% 2sd) Method GeoReM references Compiled values (wt%) SiO Mean compiled and XRF (excluding outliers) compiled from 14, 1585, 1784, 2923, 345, 3734, 808, 92 TiO Mean compiled and XRF (excluding outliers) compiled from 14, 1585, 1784, 2923, 345, 3734, 808, 92 Al 2 O Mean compiled and XRF (excluding outliers) compiled from 14, 1585, 1784, 2923, 345, 3734, 808, 92 Fe 2 O Mean compiled and XRF (excluding outliers) compiled from 14, 1585, 1784, 2923, 345, 3734, 808, 92 MnO Mean compiled and XRF (excluding outliers) compiled from 14, 1585, 1784, 2923, 345, 3734, 808, 92 MgO Mean compiled and XRF (excluding outliers) compiled from 14, 1585, 1784, 2923, 345, 3734, 808, 92 CaO Mean compiled and XRF (excluding outliers) compiled from 14, 1585, 1784, 2923, 345, 3734, 808, 92 Na 2 O Mean compiled and XRF (excluding outliers) compiled from 14, 1585, 1784, 2923, 345, 3734, 808, 92 K 2 O Mean compiled and XRF (excluding outliers) compiled from 14, 1585, 1784, 2923, 345, 3734, 808, 92 P 2 O Mean compiled and XRF (excluding outliers) compiled from 14, 1585, 1784, 2923, 345, 3734, 808, 92 LOI XRF only GeoReM data for LOI, 640 SUM ppm 2 sd % 2 sd % 2 sd GeoReM references MgO (wt%) Mean compiled and XRF (excluding outliers) compiled from 14, 1585, 1784, 2923, 345, 3734, 808, 92 Sc GeoReM mean, ICP-MS, INAA 14, 2388, 305, 345, 4028, 4211, 640, 657, 736, 97 V Mean ICP-MS and compiled 2388, 305, 92 Cr Mean GeoReM excluding 3 outliers and compiled values. All by ICP-MS 2388, 305, 4211, 97 MnO (wt%) Mean compiled and XRF (excluding outliers) compiled from 14, 1585, 1784, 2923, 345, 3734, 808, 92 Cu Mean of 3 ICP-MS 2388, 305, 4211 Zn Mean of ICP-MS and INAA 2388, 305, 4211, 640, 97 Ga GeoReM mean, ICP-MS, XRF 14, 1585, 215, 2388, 305, 345, 4211, 736, 92, 97, Rb Mean ICP-MS 24, 305, 4028, 4211, 79, 97 Sr Mean ICP-MS 2388, 24, 305, 4208, 4211, 736, 79, 97 Y Mean ICP-MS 24, 305, 4208, 4211, 736, 79, 97 Zr Mean ICP-MS 2388, 24, 305, 4208, 4211, 736, 79, 97 Nb Mean ICP-MS 2388, 24, 305, 4208, 4211, 736, 97 Cs Mean ICP-MS 2388, 24, 305, 4208, 4211, 736, 79, 97 Ba Mean ICP-MS 2388, 24, 305, 4208, 4211, 736, 79, 97 La Mean ICP-MS 2388, 24, 305, 4208, 4211, 643, 736, 79, 97 Ce Mean ICP-MS 2388, 24, 305, 4208, 4211, 643, 736, 79, 97 Pr Mean ICP-MS 2388, 24, 305, 4208, 4211, 643, 736, 79, 97 Nd Mean ICP-MS 2388, 24, 305, 4208, 4211, 643, 736, 79, 97 Sm Mean ICP-MS 2388, 24, 305, 4208, 4211, 643, 736, 79, 97 Eu Mean ICP-MS 2388, 24, 305, 4208, 4211, 643, 736, 79, 97 Gd Mean ICP-MS 2388, 24, 305, 4208, 4211, 643, 736, 79, 97 Tb Mean ICP-MS 2388, 24, 305, 4208, 4211, 643, 736, 79, 97 Dy Mean ICP-MS 2388, 24, 305, 4208, 4211, 643, 736, 79, 97 Ho Mean ICP-MS 2388, 24, 305, 4208, 4211, 643, 736, 79, 97 Er Mean ICP-MS 2388, 24, 305, 4208, 4211, 643, 736, 79, 97 Tm Mean ICP-MS 2388, 24, 4208, 4211, 736, 79, 97 Yb Mean ICP-MS 2388, 24, 305, 4208, 4211, 643, 736, 79, 97 Lu Mean ICP-MS 2388, 24, 305, 4208, 4211, 643, 736, 79, 97 Hf Mean ICP-MS 2388, 24, 305, 4208, 4211,736, 79, 97, 2056 Pb Mean ICP-MS 2388, 24, 305, 321, 4208, 736, 79, 97 Th Mean ICP-MS 2388, 24, 305, 4208, 4211,736, 79, 97 U Mean ICP-MS 2388, 24, 25, 305, 4208, 4211,736, 79, 97 Full reference details available from the GeoReM database at:

7 Table DR4. Major chemistry of matrix glass fragments from single pumice clasts determined by EPMA. All analyses carried out at Victoria University of Wellington, New Zealand using a JEOL JXA kv, 8 na and a defocused (10-15μm) electron beam. Results are reported in wt% as the mean of n analyses with the 2 sd in italics. Eruptive Unit Oruanui phase 1 Oruanui phase 1 Oruanui phase 1 Oruanui phase 1 Oruanui phase 2 Oruanui phase 2 Sample number P P P P1960 P P Pumice type Biotite-free 2 sd Biotite-free 2 sd Biotite-free 2 sd Biotite-free 2 sd Biotite-free 2 sd Biotite-free 2 sd SiO TiO Al2O FeO(T) MnO MgO n.a n.a n.a n.a n.a n.a n.a n.a n.a n.a n.a n.a CaO Na 2O K2O Original total n Eruptive Unit Oruanui phase 1 Oruanui phase 1 Oruanui phase 1 Oruanui phase 1 Oruanui phase 2 Oruanui phase 1 Sample number P (a) P (b) P P P P1639 Pumice type Biotite-bearing 2 sd Biotite-bearing 2 sd Biotite-bearing 2 sd Biotite-bearing 2 sd Biotite-bearing 2 sd Biotite-bearing 2 sd SiO TiO Al2O FeO(T) MnO MgO CaO Na2O K2O Original total n Eruptive Unit Trig 9471 Rubbish Tip Dome Sample number R828-1 R559_AA2 Magma-type NE Dome -type 2 sd NE Dome -type 2 sd SiO TiO Al2O FeO(T) MnO MgO CaO Na 2O K2O Original total n ATHO-G - Icelandic rhyolite glass standard Mean 2sd Preferred Uncertainty % diff % 2sd precision SiO TiO Al2O FeO(T) MnO MgO CaO Na 2O K2O Original total n 39

8 Table DR5. Major (EPMA) and trace element (LA-ICP-MS) chemistry of representative amphibole crystals in Oruanui and NE Dome magmas All analyses carried out at Victoria University of Wellington, New Zealand using a JEOL JXA-8230 and a New Wave 193 nm solid state laser ablation system coupled to an Agilent 7500CS ICP-MS EPMA - 15 kv, 12 na, focused electron beam; LA-ICP-MS - calibration standard was BHVO-2G, internal standard was 43 Ca, 35 μm spot diameter n.a - not analyzed; n.d - not detected. EPMA data reported as wt% and LA-ICP-MS data reported as ppm unless stated otherwise Amphiboles from Oruanui biotite-free pumice Amphiboles from Oruanui biotite-bearing pumices Amphiboles from Rubbish Tip Dome biotite rhyolite (NE Dome-type) lava Sample P1959 P1959 P1959 P1959 P1959 P1959 P1959 P1959 P1959 P1639 P1639 P1639 P1639 P1639 P1639 P1639 P1639 P1639 P1639 R559 R559 R559 R559 R559 R559 R559 R559 R559 R559 R559 Analysis label 2c 5r 4c 10r 9c 9r 11c 11r 13r 1c 1r 3c 4r 15c 15r 18c 19c 25mcd 25r 3b 2c1 2r 4r 8c 8rplc 15c 15r 16c 16r 17r Engels' amphibole standard Electron probe microanalysis Mean 2 sd Comparative values %2 sd precision SiO TiO Al 2O FeO MnO MgO CaO Na 2O K 2O Cl n.a n.a n.a n.a n.a n.a n.a n.a n.a n.a n.a n.a n.a n.a n.a n.a n.a n.a n.a n.a n.a n.a Total n = 23 Thermobarometric, oxygen fugacity and H 2O melt estimates based on the formulations of Ridolfi et al. ( Contrib. Mineral. Petrol. 160, 45-66) T ( C) P (MPa) logfo H 2O melt (wt.%) Laser ablation ICP-MS Li Sc TiO 2 (wt.%) n.a n.a n.a n.a V Mn n.a n.a n.a n.a Ni Cu n.d Zn Rb Sr Y Zr Nb Cs 0.01 n.d n.d n.d n.d n.d 0.01 n.d n.d n.d n.d Ba La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Hf Ta W 0.20 n.d n.d n.d 0.04 n.d 0.97 n.d n.d 0.11 n.d n.d n.d n.d 0.12 n.d n.d n.d Pb Th U Comparative values from Ingamells (1980) Geostandards Newsletter 4 91), 139.