Journal of Petrology Advance Access published online on January 7, 2009
Journal of Petrology, doi:10.1093/petrology/egn068
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Rhyolites and their Source Mushes across Tectonic Settings
Department of Earth and Space Sciences, University of Washington, Box 351310, Seattle, WA 98195-1310, USA
Received June 16, 2008; Revised typescript accepted November 19, 2008
 |
ABSTRACT |
|---|
 TOP ABSTRACT INTRODUCTIONTRACE ELEMENTS AND CRYSTAL...VOLATILES, MUSH TEMPERATURE AND...DISTILLING RHYOLITESTHE CHEMICALLY AND THERMALLY...SUPPLEMENTARY DATAREFERENCES |
|---|
Evolved magmas, including highly explosive rhyolites, are mainly generated by extraction of viscous melts from solid residues either in (1) partial melting zones within the crust (dominantly up-temperature evolution with newly formed silicic melt), or in (2) long-lived crystallizing mush zones fed by mafic to intermediate magmas (dominantly down-temperature evolution with residual silicic melt). Although both processes undoubtedly occur and are generally coupled, allowing for mixing between mantle and crustal components, we argue that combined field, thermal, geochemical, and geophysical observations favor residual melt extraction from crystalline mushes as the likely scenario in all tectonic settings. Depending on the main melting process in the mantle, two end-member differentiation trends occur: (1) a dry lineage leading to hot-reduced rhyolites and granites in magmatic provinces fueled by decompression melting of the mantle; (2) a wet lineage leading to cold-oxidized rhyolites and granites in subduction zones dominated by flux melting of the mantle.
KEY WORDS: rhyolite; REE; differentiation; plutonic–volcanic connection; mush
|
INTRODUCTION |
|---|
|
TOPABSTRACTINTRODUCTIONTRACE ELEMENTS AND CRYSTAL...VOLATILES, MUSH TEMPERATURE AND...DISTILLING RHYOLITESTHE CHEMICALLY AND THERMALLY...SUPPLEMENTARY DATAREFERENCES |
|---|
The origin of rhyolites deserves much attention as they generate some of the largest volcanic eruptions on record (see issue of Elements on Supervolcanoes, February 2008). One possible mechanism to produce these high-viscosity, volatile-rich, but generally crystal-poor magmas is by extracting interstitial melt trapped within large, upper crustal mush zones (defined as ‘as mixture of crystals and silicate liquid whose mobility is inhibited by a high fraction of solid particles’ Bachmann & Bergantz, 2004
; Hildreth, 2004; Eichelberger et al., 2006; Miller & Wark, 2008). This interstitial melt extraction appears to occur most efficiently when mush zones contain 50–60 vol. % crystals so that chamber-wide convection currents are hindered by the formation of a quasi-rigid crystalline skeleton (rheological transition from liquid to solid behavior occurs at 
50–60 vol. % crystals, Marsh, 1981; Brophy, 1991; Vigneresse et al., 1996; Petford, 2003) but the permeability is still high enough that melt can be efficiently extracted (McKenzie, 1985; Wickham, 1987; Bachmann & Bergantz, 2004). Most of these mush zones end up forming silicic plutons (Lipman, 1984; Bachmann et al., 2007b; Hildreth & Wilson, 2007; Lipman, 2007), although some erupt as crystal-rich ignimbrites (Lipman et al., 1997; Lindsay et al., 2001; Bachmann et al., 2002; Maughan et al., 2002).
A potential geochemical test for this hypothesis is to compare the composition of aplites with high-silica rhyolites. Aplites are highly evolved, fine-grained dyke-like structures, commonly found within granitic bodies (sensu lato), which are thought to also form by interstitial melt extraction from highly crystalline silicic magmas (e.g. Jahns & Tuttle, 1963; Miller & Mittlefehldt, 1984; Hibbard & Watters, 1985; Eichelberger et al., 2006). This geochemical comparison between aplites and high-silica rhyolites was recently attempted by Glazner et al. (2008), who reported significant differences in Sr, Y and rare earth element (REE) concentrations between them, and therefore challenged the hypothesis that voluminous high-silica rhyolites could be derived by melt extraction from large crystalline mushes of granodioritic composition.
The purpose of this paper is to re-examine the relationship between rhyolites, silicic plutons (granite sensu lato) and aplites from different tectonic settings (convergent margins, divergent margins, and hotspots, fueled by different mantle melting regimes). When integrating independent lines of evidence from geochemical, geophysical and field observations, we argue that rhyolites, silicic plutons and aplites have a clear genetic connection. This connection appears not to be restricted to any particular tectonic setting as co-magmatic silicic plutons, rhyolites, and aplites in a given magmatic province typically represent respectively the solidified mush zones, and the interstitial liquids extracted from them at different stages of evolution.
|
TRACE ELEMENTS AND CRYSTAL RESIDUES |
|---|
|
TOPABSTRACTINTRODUCTIONTRACE ELEMENTS AND CRYSTAL...VOLATILES, MUSH TEMPERATURE AND...DISTILLING RHYOLITESTHE CHEMICALLY AND THERMALLY...SUPPLEMENTARY DATAREFERENCES |
|---|
The Earth's magmatism can be roughly divided in two main trends on the basis of the dominant melting process in the mantle. In a convergent margin environment, mafic magmas (the primary drive of the Earth's magmatism; e.g. Hildreth, 1981
) arise dominantly as a result of flux melting, induced by addition of volatiles to the mantle wedge from the subducting slab (e.g. Davies & Stevenson, 1992; Schmidt & Poli, 1998; Ulmer, 2001; Parman & Grove, 2004), and differentiation trends commonly follow a fairly wet (and oxidized) path. In contrast, drier, more reduced conditions dominate in areas of mantle upwelling characteristic of hotspots, continental rifts, and mid-ocean ridges (MOR), as magmatism is produced by near-adiabatic decompression melting of the mantle (e.g. Kushiro, 2001).
The difference in PH2O and fO2 that prevails in the source regions of the different tectonic settings leads to different mineral assemblages. For example, the stability of hydrous minerals, clinopyroxene and oxides is enhanced at the expense of plagioclase in subduction zones (e.g. Holloway & Burnham, 1972; Gaetani et al., 1993). Because the mineral assemblage present during magma evolution controls the concentrations of trace elements in igneous rocks (e.g. Rollinson, 1993), silicic magmas produced in wet environments show significant differences in trace element concentrations from those in dry environments at comparable silica contents.
As pointed out by Christiansen (2005) and Christiansen & McCurry (2008), rhyolites can be divided in two categories: (1) the hot–dry–reduced rhyolites, occurring mostly above areas of mantle upwelling (hotspots and continental rifts); (2) the cold–wet–oxidized rhyolites, typically found in subduction zones. This observation appears robust despite the presence of hot–dry–reduced rhyolites in some subduction zones (e.g. Puyehue rhyolite, Gerlach et al., 1988) and cold–wet–oxidized examples in extensional environments (e.g. Bishop Tuff; Hildreth, 1979; even if the Bishop Tuff magma is not as oxidized as most arc rocks, e.g. Scaillet & Evans, 1999). Both types of rhyolites have very similar major element concentrations, but show different trace element contents; in particular, for rare earth elements (REE, Fig. 1). In wet–oxidized environments, crystallization of amphibole and titanite, which sequester middle REE (MREE) and heavy REE (HREE) (+ Y) (Frey et al., 1978; Hildreth, 1979; Lipman, 1987; Wones, 1989; Bachmann et al., 2005; Davidson et al., 2007a; Glazner et al., 2008), produces an increasingly pronounced U-shaped pattern with progressive differentiation. A deep Eu negative anomaly is not expected, because (1) plagioclase crystallization (which removes Eu and Sr from the melt) can be delayed in water-rich environments (e.g. Johannes & Holtz, 1996), and (2) titanite and amphibole do not take up Eu as much as the other REE (lower partition coefficient for Eu than adjacent REE; e.g. Bachmann et al., 2005). In contrast, the dry, reduced magmas crystallize abundant olivine, pyroxenes, and plagioclase, which do not host REE (except Eu in plagioclase). This assemblage produces REE patterns that show deep, negative Eu anomalies with otherwise fairly straight and distinctively high light REE (LREE) and HREE concentrations [the ‘seagull’ pattern of Glazner et al. (2008)].
|
With the exception of garnet, phases other than amphibole, titanite and plagioclase are unlikely to play a major role in the shape of REE patterns. In highly evolved systems (>70 wt % SiO2), REE-rich mineral phases such as allanite, chevkenite, and monazite are common (e.g. Wolff & Storey, 1984
; Bea, 1996), but as they occur late in the evolution of magmas and are always in low modal amounts, they have less opportunity to significantly fractionate REE. Only garnet is known to be an important residual phase in high-pressure hydrous mafic magmas (e.g. Hildreth & Moorbath, 1988; Müntener & Ulmer, 2006) and strongly sequesters HREE.
Rhyolites, silicic plutons, and aplites from similar tectonic environments have REE patterns that match those described above (seagull vs MREE–HREE depleted; Fig. 1). Most arc rhyolites [e.g. data from Andean rhyolites of Glazner et al. (2008, fig. 1c) and examples from the Aegean Arc, the Andes and the Taupo Volcanic zone (Fig. 1; see also supplementary data and figure, available for downloading at http//:www.petrology.oxfordjournals.org; Bryant et al., 2006; Wilson et al., 2006)] have lower MREE and HREE than high-silica rhyolites from hotspot systems and continental rifts. Conversely, REE patterns of aplites from titanite-free hosts (Glazner et al. 2008, fig. 1d) and alkaline leuco-granite (e.g. Charoy & Raimbault, 1994), are much more ‘seagull-like’, resembling the patterns of rhyolites from hotspots or continental rifts (e.g. Yellowstone, Coso, and Long Valley systems). Glazner et al. (2008) did not reach this conclusion because their focus was on REE (and Sr, Y) concentrations in aplites from the Tuolumne Intrusive Suite, produced by a regional magmatic pulse related to Cretaceous subduction (Bateman & Chappell, 1979), and they compared them with high-silica rhyolites from several magmatic centers not directly resulting from subduction processes [Yellowstone area, Coso volcanic field, SW Nevada volcanic field, Long Valley magmatic system (Glazner et al., 2008, fig. 1b)], although all tectonic settings were compared in their fig. 1c.
Admittedly, some aplites do form more pronounced U-shaped patterns than even the wettest, coldest rhyolites, but this should be expected. Aplites are mostly generated very late in the evolution of large plutonic bodies and are commonly associated with pegmatites, as pointed out by Glazner et al (2008) and several others [at least as far back as Jahns & Tuttle (1963), including those in the Tuolumne Intrusive Suite, studied by Fournier (1968)]. Aplites are typically mobilized after high-silica rhyolites, and therefore record more extreme differentiation patterns (particularly in REE) in water-rich and high-fO2 environments. Highly evolved cupolas in plutonic bodies (leuco-granites) present the same characteristics (i.e. U-shaped REE patterns; e.g. Lipman, 1987; Bryant et al., 2006). In addition, we expect a continuum of REE pattern between the two types of rhyolites; the wettest rhyolites from areas of mantle upwelling (e.g. Bishop Tuff) can have patterns that overlap with arc rhyolites (e.g. Glazner et al., 2008, fig. 1b), and the driest arc-related rhyolites can have seagull-like patterns (e.g. Mitropolous & Tarney, 1992).
|
VOLATILES, MUSH TEMPERATURE AND ERUPTABILITY |
|---|
|
TOPABSTRACTINTRODUCTIONTRACE ELEMENTS AND CRYSTAL...VOLATILES, MUSH TEMPERATURE AND...DISTILLING RHYOLITESTHE CHEMICALLY AND THERMALLY...SUPPLEMENTARY DATAREFERENCES |
|---|
Apart from the difference in REE patterns between rhyolites and aplites, other arguments have been raised against the mush extraction model for hot–dry rhyolites (e.g. Streck & Grunder, 2008
). For instance, the magmatic temperatures of these rhyolites are generally higher than those recorded for near-solidus, granodiorite mushes; also, the lack of intermediate compositions erupted in bimodal volcanic fields suggests a paucity of potential source mushy reservoirs. These two observations can be reconciled with the mush model if one considers that there are both hot and cold types of crystalline mush and that intermediate magmas have a lower probability of erupting in tectonic environments that produce the driest magmas as volatile saturation is delayed until more evolved compositions are obtained.
As for rhyolites, granites (sensu lato) have been categorized as hot–dry or cold–wet on the basis of geochemical arguments and zircon saturation temperatures (e.g. Clemens et al., 1986; Frost & Frost, 1997; King et al., 2001; Miller et al., 2003). Therefore, we propose that in hotspot systems and continental rifts, source mushes have hot–dry granitoïd compositions (e.g. Barbarin, 1990; Frost & Frost, 1997; Frost et al., 1999; Edwards & Frost, 2000; Schmitt et al., 2000), leading to high-silica rhyolites such as those found in Yellowstone, Coso, and SW Nevada, whereas convergent margins have mushes of cold–wet granodioritic composition (which sometimes erupt as large crystal-rich ignimbrites called the Monotonous Intermediates; Lindsay et al., 2001; Bachmann et al., 2002; Maughan et al., 2002; Bachmann et al., 2005) and will lead to arc rhyolites (Bachmann et al., 2007a; Hildreth, 2007; Fig. 2).
|
We concur that magmas with intermediate compositions between basalts and rhyolites, which could act as source mush zones for hot–dry–reduced rhyolites in hotspot systems and continental rifts (Streck & Grunder 2008
), are rare in the volcanic record [the ‘Daly Gap’; recognized since Daly (1925) in bimodal volcanic fields] but not in the plutonic realm. Although alkaline plutonic bodies of intermediate composition (syenites, alkali granitoids) may be scarcer than calc-alkaline granodiorites, they cannot be considered rare (e.g. Clemens et al., 1986; Eby, 1990; Chappell et al., 1998; Frost et al., 2001) and are typically found in the same tectonic settings as the hot–dry–reduced rhyolites.
The paucity of erupted intermediate magmas is a likely consequence of the same fundamental difference that generates distinct types of REE patterns: abundance of volatiles in the magmatic crustal column. As demonstrated by the seminal work of Geist et al. (1995) on rhyolites from Volcàn Alcedo (Galapagos Archipelago), evolved magmas are expected to be eruptible only after they become saturated with volatiles (either by progressive enrichment as a result of crystallization of anhydrous phases and/or addition from the surrounding crust). In both tectonic settings, basalts generally erupt from deep sources by processes independent of volatile saturation, but when these mafic magmas stall in the crust (triggering differentiation), the compositions of subsequently erupted magmas depends on the relative timing of volatile saturation and rheological lock-up, as follows.
In volatile-rich systems, under upper crustal conditions, volatile saturation is reached at intermediate compositions, increasing the likelihood that such compositions will be erupted (Fig. 3). Therefore, andesite–dacitic compositions dominate the volcanic record in subduction zones (e.g. Gill, 1981). More evolved compositions (rhyolites) are rare in subduction zones (Hildreth, 2007) because (1) their parental magmas (andesite or dacite) erupt, and (2) when they do form, rapid crystallization induced by volatile exsolution renders these volatile-laden systems generally too crystal-rich to erupt (Cashman & Blundy, 2000; Miller et al., 2003).
|
In drier systems, rheological lock-up by cooling-induced crystallization is reached before volatile saturation for the intermediate compositions. Therefore, most alkaline andesites and dacites do not erupt. More differentiation is required for volatiles to accumulate and eruption to occur (Fig. 3), leading to the observed bimodal distribution of chemical compositions of erupted products in hotspots and continental rifts.
|
DISTILLING RHYOLITES |
|---|
|
TOPABSTRACTINTRODUCTIONTRACE ELEMENTS AND CRYSTAL...VOLATILES, MUSH TEMPERATURE AND...DISTILLING RHYOLITESTHE CHEMICALLY AND THERMALLY...SUPPLEMENTARY DATAREFERENCES |
|---|
Silicic magmas can form either by partial melting of metaigneous and metasedimentary supracrustal materials (see recent references e.g. Bindeman et al., 2008
; Bryan et al., 2008; Glazner et al., 2008; Streck & Grunder, 2008) or by fractional crystallization (± assimilation) of mafic parents [countless references since Daly (1914) and Bowen (1928)]. The mush model favors neither of them, as the 50–60 vol. % crystal window can be achieved by either partial melting (up temperature) or progressive crystallization (down temperature). As discussed above, trace (and major) element geochemistry mostly reflects P–T–PH2O and fO2 conditions in the magma source zones, but has generally been unsuccessful in discriminating between the two processes (see Brophy, 2008). However, by examining lines of evidence that are largely independent of geochemistry, we conclude that crustal melting will be typically less important than fractional crystallization in producing high-SiO2 magmas. We also stress that magma columns will be dominated by mush zones (e.g. Marsh, 2004) and interstitial liquid extraction when magmas reach intermediate crystallinities.
Melting of pre-existing crustal rocks has been a popular hypothesis for decades, and has become the paradigm for generating silicic magmas following the recognition of ‘restitic material’ (xenoliths and xenocrystic material) in most large silicic units (e.g. Friedman et al., 1974; Worner et al., 1985; Chappell et al., 1987; Gunnarsson et al., 1998; Charlier et al., 2007; Bindeman et al., 2008; Bryan et al., 2008). In addition, unambiguous isotopic evidence for recycling of crustal material (e.g. Faure, 2001; Davidson et al., 2007b) indicates that silicic magmas are open to mass exchange with surrounding crust, and the presence in the rock record of peraluminous felsic rocks suggests that some evolved magmas may be pure partial melts of pelitic material (Munksgaard, 1984; Pichavant et al., 1988; Mahood et al., 1996; Zeck & Williams, 2002; Clarke et al., 2005). Lastly, at least since the publication of the famous memoir by Tuttle & Bowen (1958), crustal melting is thought to alleviate the heat and room problems associated with the emplacement of large bodies of silicic magmas in the mid- to upper crust.
However, modeling efforts to better constrain the heat budget in basalt–crust interaction (Barboza et al., 1999; Babeyko et al., 2002; Dufek & Bergantz, 2005; Annen et al., 2006) has led to different views, particularly for the large and abundant metaluminous units. State-of-the-art numerical simulations of the energy balance between mafic magmas and the pre-existing crust illustrate how difficult it is to form volumetrically significant amounts of pure crustal melts, even in the deep crust (Barboza et al., 1999; Babeyko et al., 2002; Dufek & Bergantz, 2005; Annen et al., 2006). A very high heat flow from the mantle is required (> 60 mW/m2; Babeyko et al., 2002), and even in these hot conditions, only the lowermost crust can melt in any significant amounts (using the well-constrained melting behaviors of pelites and amphibolites; Barboza et al., 1999; Babeyko et al., 2002; Dufek & Bergantz, 2005; Annen et al., 2006). Even remelting young intrusive rocks requires large amounts of enthalpy and volatiles (Brown, 2007). Heat and water that inevitably escape during solidification must be replenished by the incoming magmas (e.g. Miller et al., 2003).
In addition to the numerical models of heat and mass transfer within the crust, field observations in exposed crustal sections (the natural laboratories) are also in disagreement with crustal melting being the dominant process in producing voluminous silicic magma bodies. Crustal sections, although sparse (Barboza & Bergantz, 2000; Greene et al., 2006; Jagoutz et al., 2007; Hacker et al., 2008), suggest that widespread crustal melting does not occur even when large pools of mafic melts intrude the lower to mid-crust (Barboza & Bergantz, 2000). Careful investigations of these sections (Voshage et al., 1990; Barboza et al., 1999; Greene et al., 2006; Jagoutz et al., 2007) all conclude that fractional crystallization of mantle-derived basalts occurring synchronously with some assimilation (energy-constrained AFC; e.g. Reiners et al., 1995; Bohrson & Spera, 2001; Thompson et al., 2002) is the dominant differentiation process.
We argue that, by analogy to basaltic lenses in mid-ocean ridges (e.g. Sinton & Detrick, 1992), magmas feeding upper continental crust reservoirs are also generated by interstitial liquid extraction from crystalline mushes (Fig. 4; see also Wickham, 1987; Quick et al., 1994). The presence of crustal ‘restitic’ material in silicic magmas (including xenocrysts) can be reconciled by partial assimilation of wall-rocks (both in the lower and upper crust; e.g. DePaolo, 1981; DePaolo et al., 1992; Bohrson & Spera, 2001; Beard et al., 2004, 2005), and does not necessarily require an origin by pure crustal melting. Most silicic magmas bodies unquestionably undergo open-system behavior and can blend components from both the mantle and the crust [many decades of references, at least since Daly (1914) and Bowen (1928)]. Energy-efficient reactive bulk assimilation has been recognized in both plutonic (Voshage et al., 1990; Beard et al., 2004, 2005) and volcanic (Charlier et al., 2007) environments.
|
|
THE CHEMICALLY AND THERMALLY OPEN-SYSTEM MUSH MODEL AS THE EARTH'S WAY OF PRODUCING SILICIC MAGMAS |
|---|
|
TOPABSTRACTINTRODUCTIONTRACE ELEMENTS AND CRYSTAL...VOLATILES, MUSH TEMPERATURE AND...DISTILLING RHYOLITESTHE CHEMICALLY AND THERMALLY...SUPPLEMENTARY DATAREFERENCES |
|---|
The varieties of physical processes that produce distinct trends of magmatic differentiation are rarely fully expressed through a single chemical index or line of evidence. The mush model discussed herein is based on specific and explicit links between plutons and volcanic systems, and much of the supporting evidence, including field relationships, temporal–compositional relationships and geophysical observations, has been summarized elsewhere (Bachmann & Bergantz, 2004
; Hildreth, 2004; Marsh, 2004; Bachmann et al., 2007b; Lees, 2007). Hence, we stress, using all the lines of evidence we could assemble, that interstitial liquid extraction from highly crystalline, long-lived mushes that are open to additions of mass and heat can provide a rationalizing framework to explain compositional diversity among magmas. Crystal mushes physically and chemically control magmatic differentiation and can produce the distinct characteristics observed in rhyolites, from the hot and dry conditions in continental rifts and hotspots, to the colder and wetter magmas more typical in subduction zones. |
SUPPLEMENTARY DATA |
|---|
|
TOPABSTRACTINTRODUCTIONTRACE ELEMENTS AND CRYSTAL...VOLATILES, MUSH TEMPERATURE AND...DISTILLING RHYOLITESTHE CHEMICALLY AND THERMALLY...SUPPLEMENTARY DATAREFERENCES |
|---|
Supplementary data for this paper are available at Journal of Petrology online.
|
ACKNOWLEDGEMENTS |
|---|
We acknowledge the financial support of the Swiss National Science Foundation to O.B. and NSF EAR-0440391 and EAR-0711551 to G.W.B. Many thanks go to Calvin Miller, Jonathan Miller, Jim Beard, Denny Geist, and Peter Lipman for constructive comments on earlier versions of this manuscript, and to Bruce Marsh, Eric Christiansen and an anonymous reviewer for thoroughly assessing this work. The efficient editorial handling by Ron Frost is also gratefully acknowledged.
*Corresponding author. E-mail: bachmano{at}u.washington.edu
|
REFERENCES |
|---|
|
TOPABSTRACTINTRODUCTIONTRACE ELEMENTS AND CRYSTAL...VOLATILES, MUSH TEMPERATURE AND...DISTILLING RHYOLITESTHE CHEMICALLY AND THERMALLY...SUPPLEMENTARY DATAREFERENCES |
|---|
Allen S. R. Reconstruction of a major caldera-forming eruption from pyroclastic deposit characteristics: Kos Plateau Tuff, eastern Aegean Sea. Journal of Volcanology and Geothermal Research (2001) 105:141–162.[CrossRef][Web of Science]
Annen C., Scaillet B., Sparks R. S. J. Thermal constraints on the emplacement rate of a large intrusive complex: the Manaslu Leucogranite, Nepal Himalaya. Journal of Petrology (2006) 47:71–95.
Babeyko A. Y., Sobolev S. V., Trumbull R. B., Oncken O., Lavier L. L. Numerical models of crustal scale convection and partial melting beneath the Altiplano–Puna plateau. Earth and Planetary Science Letters (2002) 199:373–388.[CrossRef][Web of Science]
Bachmann O., Bergantz G. W. On the origin of crystal-poor rhyolites: extracted from batholithic crystal mushes. Journal of Petrology (2004) 45:1565–1582.
Bachmann O., Charlier B. L. A., Lowenstern J. B. Zircon crystallization and recycling in the magma chamber of the rhyolitic Kos Plateau Tuff (Aegean Arc). Geology (2007a) 35:73–76.
Bachmann O., Dungan M. A., Bussy F. Insights into shallow magmatic processes in large silicic magma bodies: the trace element record in the Fish Canyon magma body, Colorado. Contributions to Mineralogy and Petrology (2005) 149:338–349.[CrossRef][Web of Science]
Bachmann O., Dungan M. A., Lipman P. W. The Fish Canyon magma body, San Juan volcanic field, Colorado: rejuvenation and eruption of an upper crustal batholith. Journal of Petrology (2002) 43:1469–1503.
Bachmann O., Miller C. F., de Silva S. The volcanic–plutonic connection as a stage for understanding crustal magmatism. Journal of Volcanology and Geothermal Research (2007b) 167:1–23.[CrossRef][Web of Science]
Barbarin B. Granitoids: Main petrogenetic classification in relation to origin and tectonic setting. Geological Journal (1990) 25:227–238.[CrossRef][Web of Science]
Barboza S. A., Bergantz G. W. Metamorphism and anatexis in the mafic complex contact aureole, Ivrea Zone, Northern Italy. Journal of Petrology (2000) 41:1307–1327.
Barboza S. A., Bergantz G. W., Brown M. Regional granulite facies metamorphism in the Ivrea zone: Is the Mafic Complex the smoking gun or a red herring? Geology (1999) 27:447–450.
Bateman P. C., Chappell B. W. Crystallization, fractionation, and solidification of the Tuolumne Intrusive Series, Yosemite National Park, California. Geological Society of America Bulletin (1979) 90:465–482.
Bea F. Residence of REE, Y, Th, and U in granites and crustal protoliths; implications for the chemistry of crustal melts. Journal of Petrology (1996) 37:521–552.
Beard J. S., Ragland P. C., Crawford M. L. Reactive bulk assimilation: A model for crust–mantle mixing in silicic magmas. Geology (2005) 33:681–684.
Beard J. S., Ragland P. C., Rushmer T. Hydration crystallization reactions between anhydrous minerals and hydrous melt to yield amphibole and biotite in igneous rocks: Description and implications. Journal of Geology (2004) 112:617–621.[CrossRef][Web of Science]
Bindeman I. N., Fu B., Kita N. T., Valley J. W. Origin and evolution of silicic magmatism at Yellowstone based on ion microprobe analysis of isotopically zoned zircons. Journal of Petrology (2008) 49:163–193.
Bohrson W. A., Spera F. J. Energy-constrained open-system magmatic processes II: application of energy-constrained assimilation–fractional crystallization (EC-AFC) model to magmatic systems. Journal of Petrology (2001) 42:1019–1041.
Bowen NL. The Evolution of Igneous Rocks (1928) New York: Dover.
Brophy J. A study of rare earth element (REE)–SiO2 variations in felsic liquids generated by basalt fractionation and amphibolite melting: a potential test for discriminating between the two different processes. Contributions to Mineralogy and Petrology (2008) 156:337–357.[CrossRef][Web of Science]
Brophy J. G. Composition gaps, critical crystallinity, and fractional crystallization in orogenic (calc-alkaline) magmatic systems. Contributions to Mineralogy and Petrology (1991) 109:173–182.[CrossRef][Web of Science]
Brown M. H. Crustal melting and melt extraction, ascent and emplacement in orogens: mechanisms and consequences. Journal of the Geological Society, London (2007) 164:709–730.
Bryan S. E., Ferrari L., Reiners P. W., Allen C. M., Petrone C. M., Ramos-Rosique A., Campbell I. H. New insights into crustal contributions to large-volume rhyolite generation in the Mid-Tertiary Sierra Madre Occidental Province, Mexico, revealed by U–Pb geochronology. Journal of Petrology (2008) 49:47–77.
Bryant J. A., Yogodzinski G. M., Hall M. L., Lewicki J. L., Bailey D. G. Geochemical constraints on the origin of volcanic rocks from the Andean Northern Volcanic Zone, Ecuador. Journal of Petrology (2006) 47:1147–1175.
Cashman K., Blundy J. Degassing and crystallization of ascending andesite and dacite. Philosophical Transactions of the Royal Society of London (2000) 358:1487–1513.[CrossRef][Web of Science]
Chappell B. W., White A. J. R., Hine R. Granite provinces and basement terranes in the Lachlan Fold Belt, southeastern Australia. Australian Journal of Earth Sciences (1998) 35:505–521.[CrossRef]
Chappell B. W., White A. J. R., Wyborn D. The importance of residual source material (restite) in granite petrogenesis. Journal of Petrology (1987) 28:1111–1138.
Charlier B. L. A., Bachmann O., Davidson J. P., Dungan M. A., Morgan D. The upper crustal evolution of a large silicic magma body: evidence from crystal-scale Rb/Sr isotopic heterogeneities in the Fish Canyon magmatic system, Colorado. Journal of Petrology (2007) 48:1875–1894.
Charoy B., Raimbault L. Zr-, Th-, and REE-rich biotites differentiates in the A-type granite pluton of Suzhou (Eastern China): the key role of fluorine. Journal of Petrology (1994) 35:919–962.
Christiansen E. H. Contrasting processes in silicic magma chambers: evidence from very large volume ignimbrites. Geological Magazine (2005) 142:669–681.
Christiansen E. N., McCurry M. Contrasting origins of Cenozoic silicic volcanic rocks from the western Cordillera of the United States. Bulletin of Volcanology (2008) 70:251–267.[CrossRef][Web of Science]
Clarke DB, Dorais M, Barbarin B, et al. Occurrence and origin of andalusite in peraluminous felsic igneous rocks. Journal of Petrology (2005) 46:441–472.
Clemens J. D., Holloway J. R., White A. J. R. Origin of an A-type granite; experimental constraints. American MIneralogist (1986) 71:317–324.[Abstract]
Daly RA. Igneous Rocks and their Origin (1914) London: McGraw–Hill.
Daly R. A. The geology of Ascension Island. Proceedings of the American Academy of Arts and Sciences (1925) 60:1–80.
Davidson J., Turner S., Handley H., Macpherson C., Dosseto A. Amphibole ‘sponge’ in arc crust? Geology (2007a) 35:787–790.
Davidson J. P., Morgan D. J., Charlier B. L. A., Harlou R., Hora J. M. Microsampling and isotopic analysis of igneous rocks: implications for the study of magmatic systems. Annual Review of Earth and Planetary Sciences (2007b) 35:273–311.[CrossRef][Web of Science]
Davies J. H., Stevenson D. J. Physical model of source region of subduction zone volcanics. Journal of geophysical Research (1992) 92:2037–2070.
DePaolo D. J. Trace element and isotopic effects of combined wallrock assimilation and fractional crystallization. Earth and Planetary Science Letters (1981) 53:189–202.[CrossRef][Web of Science]
DePaolo D. J., Perry F. V., Baldridge W. S. Crustal versus mantle sources in granitic magmas: A two-parameters model based on Nd isotope studies. Transactions of the Royal Society of Edinburgh (1992) 83:439–446.
Dufek J., Bergantz G. W. Lower crustal magma genesis and preservation: a stochastic framework for the evaluation of basalt–crust interaction. Journal of Petrology (2005) 46:2167–2195.
Eby G. N. The A-type granitoids: a review of their occurrence and chemical characteristics and speculations on their petrogenesis. Lithos (1990) 26:115–134.[CrossRef][Web of Science]
Edwards B. R., Frost C. D. An overview of the petrology and geochemistry of the Sherman batholith, southeastern Wyoming: Identifying multiple sources of Mesoproterozoic magmatism. Rocky Mountain Geology (2000) 35:113–137.
Eichelberger J. C., Izbekov P. E., Browne B. L. Bulk chemical trends at arc volcanoes are not liquid lines of descent. Lithos (2006) 87:135–154.[CrossRef][Web of Science]
Erikson E. H. Petrology and petrogenesis of the Mount Stuart batholith—plutonic equivalent of the high-alumina basalt association? Contributions to Mineralogy and Petrology (1977) 60:183–207.[CrossRef][Web of Science]
Faure G. Origin of Igneous Rocks: the Isotopic Evidence (2001) Berlin: Springer.
Fournier R. B. Mechanisms of alaskite, aplite and pegmatite in a dike swarm, Yosemite National Park, California. In: Studies in Volcanology: A memoir in Honor of Howell Williams, Geological Society of America Memoir —Coats R. R., Hay R. L., Anderson C. A., eds. (1968) 116:249–274.
Frey F. A., Chappell B. W., Stephen D. R. Fractionation of rare-earth elements in the Tuolumne Intrusive Series. Geology (1978) 6:239–242.
Friedman I., Lipman P. W., Obradovich J. D., Gleason J. D., Christiansen R. L. Meteoric water in magmas. Science (1974) 184:1069–1072.
Frost B. R., Barnes C. G., Collins W. J., Arculus R. J., Ellis D. J., Frost C. D. A geochemical classification for granitic rocks. Journal of Petrology (2001) 42:2033–2048.
Frost C. D., Frost B. R. Reduced rapakivi-type granites; the tholeiite connection. Geology (1997) 25:647–650.
Frost C. D., Frost B. R., Chamberlain K. R., Edwards B. R. Petrogenesis of the 1
43 Ga Sherman Batholith, SE Wyoming, USA: a reduced, rapakivi-type anorogenic granite. Journal of Petrology (1999) 40:1771–1802.[CrossRef][Web of Science]
Gaetani G. A., Grove T. L., Bryan W. B. The influence of water on the petrogenesis of subduction-related igneous rocks. Nature (1993) 365:332–334.[CrossRef]
Geist D., Howard K. A., Larson P. The generation of oceanic rhyolites by crystal fractionation: the basalt–rhyolite association at Volcan Alcedo, Galapagos Archipelago. Journal of Petrology (1995) 36:965–982.
Gerlach D. C., Frey F. A., Moreno-Roa H., Lopez-Escobar L. Recent volcanism in the Puyehue–Cordon Caulle region, Southern Andes, Chile (40°S): petrogenesis of evolved lavas. Journal of Petrology (1988) 29:333–382.
Ghiorso M. S., Sack R. O. Chemical mass transfer in magmatic processes IV: A revised and internally consistent thermodynamic model for the interpolation and extrapolation of liquid–solid equilibria in magmatic systems at elevated temperatures and pressures. Contributions to Mineralogy and Petrology (1995) 119:197–212.[Web of Science]
Gill JB. Orogenic Andesites and Plate Tectonics (1981) Berlin: Springer.
Glazner A. F., Coleman D. S., Bartley J. M. The tenuous connection between high-silica rhyolites and granodiorite plutons. Geology (2008) 36:1047–1050.
Greene A. R., Debari S. M., Kelemen P. B., Blusztajn J., Clift P. D. A detailed geochemical study of island arc crust: the Talkeetna Arc Section, South–Central Alaska. Journal of Petrology (2006) 47:1051–1093.
Gunnarsson B., Marsh B. D., Taylor H. P. U. R. Jr. Generation of Icelandic rhyolites: silicic lavas from the Torfajokull central volcano. Journal of Volcanology and Geothermal Research (1998) 83:1–45.[CrossRef][Web of Science]
Hacker B. R., Mehl L., Kelemen P. B., Rioux M., Behn M. D., Luffi P. Reconstruction of the Talkeetna intraoceanic arc of Alaska through thermobarometry. Journal of Geophysical Research (2008) 113. B03204, doi:10.1029/2007JB005208.
Hibbard M. J., Watters R. J. Fracturing and diking in incompletely crystallized granitic plutons. Lithos (1985) 18:1–12.[CrossRef][Web of Science]
Hildreth W. The Bishop Tuff: evidence for the origin of the compositional zonation in silicic magma chambers. In: Ash-Flow Tuffs, Geological Society of America, Special Papers —Chapin C. E., Elston W. E., eds. (1979) 180:43–76.
Hildreth W. Gradients in silicic magma chambers: Implications for lithospheric magmatism. Journal of Geophysical Research (1981) 86:10153–10192.
Hildreth W. Volcanological perspectives on Long Valley, Mammoth Mountain, and Mono Craters: several contiguous but discrete systems. Journal of Volcanology and Geothermal Research (2004) 136:169–198.[CrossRef][Web of Science]
Hildreth WS. Quaternary Magmatism in the Cascades—Geological Perspectives. (2007) 1744. US Geological Survey, Professional Papers.
Hildreth W. S., Moorbath S. Crustal contributions to arc magmatism in the Andes of Central Chile. Contributions to Mineralogy and Petrology (1988) 98:455–499.[CrossRef][Web of Science]
Hildreth W. S., Wilson C. J. N. Compositional zoning in the Bishop Tuff. Journal of Petrology (2007) 48:951–999.
Holloway J. R., Burnham C. W. Melting relations of basalt with equilibrium water pressure less than total pressure. Journal du Petrole (1972) 13:1–29.
Jagoutz O., Müntener O., Ulmer P., Pettke T., Burg J.-P., Dawood H., Hussain S. Petrology and mineral chemistry of lower crustal intrusions: the Chilas Complex, Kohistan (NW Pakistan). Journal of Petrology (2007) 48:1895–1953.
Jahns R. H., Tuttle O. F. Layered pegmatites–aplites intrusives. Mineralogical Society of America, Special Paper (1963) 1:78–92.
Johannes, W. & Holtz F. Petrogenesis and Experimental Petrology of Granitic Rocks (1996) 335 pp: Berlin: Springer.
King P. L., Chappell B. W., Allen C. M., White A. J. R. Are A-type granites the high-temperature felsic granites? Evidence from fractionated granites of the Wangrah Suite. Australian Journal of Earth Sciences (2001) 48:501–514.[CrossRef][Web of Science]
Kushiro I. Partial melting experiments on peridotite and origin of mid-ocean ridge basalt. Annual Review of Earth and Planetary Sciences (2001) 29:71–107.[CrossRef][Web of Science]
Lees J. M. Seismic tomography of magmatic systems. Journal of Volcanology and Geothermal Research (2007) 167:37–56.[CrossRef][Web of Science]
Lindsay J. M., Schmitt A. K., Trumbull R. B., De Silva S. L., Siebel W., Emmermann R. Magmatic evolution of the La Pacana caldera system, Central Andes, Chile: Compositional variation of two cogenetic, large-volume felsic ignimbrites. Journal of Petrology (2001) 42:459–486.
Lipman P. W. The roots of ash-flow calderas in western North America: windows into the tops of granitic batholiths. Journal of Geophysical Research (1984) 89(B10):8801–8841.
Lipman P. W. Rare-earth-element compositions of Cenozoic volcanic rocks in the southern Rocky Mountains and adjacent areas. US Geological Survey Bulletin (1987) 1668:1–23.
Lipman P. W. Incremental assembly and prolonged consolidation of Cordilleran magma chambers: Evidence from the Southern Rocky Mountain volcanic field. Geosphere (2007) 3:1–29.
Lipman P. W., Dungan M. A., Bachmann O. Comagmatic granophyric granite in the Fish Canyon Tuff, Colorado: Implications for magma-chamber processes during a large ash-flow eruption. Geology (1997) 25:915–918.
Mahood G. A., Nibler G. E., Halliday A. N. Zoning patterns and petrologic processes in peraluminous magma chambers; Hall Canyon Pluton, Panamint Mountains, California. Geological Society of America Bulletin (1996) 108:437–453.
Marsh B. D. On the crystallinity, probability of occurrence, and rheology of lava and magma. Contributions to Mineralogy and Petrology (1981) 78:85–98.[CrossRef][Web of Science]
Marsh B. D. A magmatic mush column Rosetta Stone: the McMurdo Dry Valleys of Antarctica. EOS Transactions, American Geophysical Union (2004) 85:497–502.
Maughan L. L., Christiansen E. H., Best M. G., Gromme C. S., Deino A. L., Tingey D. G. The Oligocene Lund Tuff, Great Basin, USA: a very large volume monotonous intermediate. Journal of Volcanology and Geothermal Research (2002) 113:129–157.[CrossRef][Web of Science]
McKenzie D. P. The extraction of magma from the crust and mantle. Earth and Planetary Science Letters (1985) 74:81–91.[CrossRef][Web of Science]
McNulty B. A., Tobish O. T., Cruden A. R., Gilder S. Multi-stage emplacement of the Mount Givens pluton, central Sierra Nevada batholith, California. Geological Society of America Bulletin (2000) 112:119–135.
Miller C. F., Meschter McDowell S., Mapes R. W. Hot and cold granites? Implications of zircon saturation temperatures and preservation of inheritance. Geology (2003) 31:529–532.
Miller C. F., Mittlefehldt D. W. Extreme fractionation in felsic magma chambers: a product of liquid-state diffusion or fractional crystallization? Earth and Planetary Science Letters (1984) 68:151–158.[CrossRef][Web of Science]
Miller C. F., Wark D. A. Supervolcanoes and their explosive supereruptions. Elements (2008) 4:11–16.
Mitropolous P., Tarney J. Significance of mineral composition variations in the Aegean Island Arc. Journal of Volcanology and Geothermal Research (1992) 51:283–303.[CrossRef][Web of Science]
Munksgaard N. C. High 
18O and possibly pre-eruptional Rb-Sr isochrons in cordierite-bearing Neogene volcanics from SE Spain. Contributions to Mineralogy and Petrology (1984) 87:351–358.[CrossRef][Web of Science]
Müntener O, Ulmer P. Experimentally derived high-pressure cumulates from hydrous arc magmas and consequences for the seismic velocity structure of lower arc crust. Geophysical Research Letters (2006) 33. doi:10.1029/2006GL027629.
Parman S. W., Grove T. L. Harzburgite melting with and without H2O: Experimental data and predictive modeling. Journal of Geophysical Research (2004) 109. B02201, doi:10.1029/2003JB002566.
Pe-Piper G., Piper D. J. W., Perissoratis C. Neotectonics and the Kos Plateau Tuff eruption of 161 ka, South Aegean arc. Journal of Volcanology and Geothermal Research (2005) 139:315–338.[CrossRef][Web of Science]
Petford N. Rheology of granitic magmas during ascent and emplacement. Annual Review of Earth and Planetary Sciences (2003) 31:399–427.[CrossRef][Web of Science]
Pichavant M., Kontak D. J., Briqueu L., Herrera J. V., Clark A. H. The Miocene–Pliocene Macusani Volcanics, SE Peru, 2. Geochemistry and origin of felsic peraluminous magma. Contributions to Mineralogy and Petrology (1988) 100:325–338.[CrossRef][Web of Science]
Quick J. E., Sinigoi S., Mayer A. Emplacement dynamics of a large intrusion in the lower crust of the Ivrea–Verbano Zone, northern Italy. Journal of Geophysical Research (1994) 99:21559–21573.[CrossRef]
Reiners P. W., Nelson B. K., Ghiorso M. S. Assimilation of felsic crust and its partial melt by basaltic magma: thermal limits and extent of crustal contamination. Geology (1995) 23:563–566.
Rollinson H. Using Geochemical Data: Evaluation, Presentation and Interpretation (1993) Harlow: Addison Wesley–Longman.
Scaillet B., Evans B. W. The 15 June 1991 eruption of Mount Pinatubo. I. Phase equilibria and pre-eruption P–T–fO2–fH2O conditions of the dacite magma. Journal of Petrology (1999) 40:381–411.[CrossRef][Web of Science]
Schmidt M. W., Poli S. Experimentally based water budgets for dehydrating slabs and consequences for arc magma generation. Earth and Planetary Science Letters (1998) 163:361–379.[CrossRef][Web of Science]
Schmitt A. K., Emmermann R., Trumbull R. B., Buhn B., Henjes-Kunst F. Petrogenesis and 40Ar/39Ar geochronology of the Brandberg Complex, Namibia: evidence for a major mantle contribution in metaluminous and peralkaline granites. Journal of Petrology (2000) 41:1207–1239.
Sinton J. M., Detrick R. S. Mid-ocean ridge magma chambers. Journal of Geophysical Research (1992) 97:197–216.
Streck M., Grunder A. Phenocryst-poor rhyolites of bimodal, tholeiitic provinces: the Rattlesnake Tuff and implications for mush extraction models. Bulletin of Volcanology (2008) 70:385–401.[CrossRef][Web of Science]
Thompson A. B., Matile L., Ulmer P. Some thermal constraints on crustal assimilation during fractionation of hydrous, mantle-derived magmas with examples from Central Alpine batholiths. Journal of Petrology (2002) 43:403–422.
Tuttle OF, Bowen NL. Origin of Granite in Light of Experimental Studies in the System NaAlSi3O8–KAlSi3O8–SiO2 (1958) 74. Geological Society of America, Memoirs. 153.
Ulmer P. Partial melting in the mantle wedge—the role of H2O in the genesis of mantle-derived ‘arc-related’ magmas. Physics of the Earth and Planetary Interiors (2001) 127:581–593.
Vigneresse J.-L., Barbey P., Cuney M. Rheological transitions during partial melting and crystallization with application to felsic magma segregation and transfer. Journal of Petrology (1996) 37:1579–1600.
Voshage H., Hofmann A. W., Mazzucchelli M., Rivalenti G., Sinigoi S., Raczek I., Demarchi G. Isotopic evidence from the Ivrea Zone for a hybrid lower crust formed by magmatic underplating. Nature (1990) 347:731–736.[CrossRef]
Wickham S. M. The segregation and emplacement of granitic magmas. Journal of the Geological Society, London (1987) 144:281–297.
Wilson C. J. N., Blake S., Charlier B. L. A., Sutton A. N. The 26·5 ka Oruanui eruption, Taupo Volcano, New Zealand: development, characteristics and evacuation of a large rhyolitic magma body. Journal of Petrology (2006) 47:35–69.
Wolff J. A., Storey M. Zoning in highly alkaline magma bodies. Geological Magazine (1984) 121:563–575.[Abstract]
Wones D. R. Significance of the assemblage titanite + magnetite + quartz in granitic rock. American Mineralogist (1989) 74:744–749.[Abstract]
Worner G., Staudigel H., Zindler A. Isotopic constraints on open system evolution of the Laacher See magma chamber (Eifel, West Germany). Earth and Planetary Science Letters (1985) 75:37–49.[CrossRef][Web of Science]
Zeck H. P., Williams I. S. Inherited and magmatic zircon from Neogene Hoyazo cordierite dacite, SE Spain–anatectic source rock provenance and magmatic evolution. Journal of Petrology (2002) 43:1089–1104.
CiteULike 
Connotea 
Del.icio.us What's this?
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||