Volatile Element Systematics of Hawaiian Shield Volcanoes  

Erik Hauri, Jared Marske, Michael Garcia, Aaron Pietruszka, Frank Trusdell

•  Shield-stage magmas; correlated majors, traces, isotopes •  These correlations indicate variations in mantle source •  Determine if there are differences in source volatile content •  Test ideas on depth of magma delivery to rift zones •  Determine magma ascent rates at summit and rift zones

•  Requirements for accurate determination of volatiles in source •  Fast quench rates

•  Submarine glasses •  Glassy melt inclusions (tephra)

•  Minimal degassing (CO2 - S - H2O) •  Deeply erupted (submarine) or deeply sourced (melt inclusions)

•  Range of major element - trace element - isotope data

Now, that a heavy liquid should be mobile need not cause surprise…this is to be found, I believe, in its high gas content. – Frank Perret (1913), Lava Fountains of Kilauea, Am. J. Sci.

•  Ion Microprobe •  10µm spatial resolution •  Reproducibility 2-3% (2σ) •  Accuracy ~10% •  Rapid data acquisition (10 min)

Re/Os -> 187Os/188Os

Re

Os isotope variations are strongly controlled by mixing ratio of eclogite/peridotite

Os

•  Shield-stage magmas; correlated majors, traces, isotopes

Hauri et al. (1996)

•  Shield-stage magmas; correlated majors, traces, isotopes

Hauri et al. (1996)

•  Shield-stage magmas; correlated majors, traces, isotopes

Lassiter & Hauri (1998)

•  Shield-stage magmas; correlated majors, traces, isotopes

Hauri (1996)

•  Shield-stage magmas; correlated majors, traces, isotopes

Hauri (1996)

•  Shield-stage magmas; correlated majors, traces, isotopes

Hauri (1996)

•  Shield-stage magmas; correlated majors, traces, isotopes

Hauri (1996)

•  Major elements + volatiles

Stolper et al. (2004)

n=4192

•  Major elements + volatiles + trace elements

Stolper et al. (2004)

n=852

•  Major elements + volatiles + traces + isotopes •  Shield-stage •  Minimal degassing (S - H2O)

Stolper et al. (2004)

n=94

Hauri (2002)

•  Major elements + volatiles + traces + isotopes •  Shield-stage •  Minimal degassing (S - H2O)

Stolper et al. (2004)

n=94

Degassing

10%

90%

Cartigny et al. 2008

.  

10  

100

1000

10000

0.1   1   10 100 Nb [ppm]

CO2 [

ppm

]

Iceland NVZ CO2/Nb=400

Siqueiros MI CO2/Nb =240

MORB

Depleted

Enriched ?

Kilauea (Gerlach et al., 2002)

•  Combined major-trace-isotope-volatile data sets very limited •  H2O/Ce variations limited by data, uncertainties in degassing •  Submarine glasses pervasively contaminated with seawater Cl •  Suggestions of Cl differences among Hawaiian volcanoes (MI) •  Insufficient data on F contents to evaluate •  High primary CO2 contents consistent with global variations

Mahalo