The link between Hawaiian mantle plume composition, magmatic flux, and deep mantle geodynamics
Introduction
Long-lived intraplate oceanic islands and chains such as Iceland, Kerguelen, and Hawai‘i are typically explained as the products of mantle plumes (Morgan, 1972, Boschi et al., 2007). Hawai‘i is one of the most studied examples of such volcanism because it has a well-documented age progression along the chain (O'Connor et al., 2013, Garcia et al., 2015), is far from continent and mid-ocean ridge sources of contamination, has a deep mantle source (French and Romanowicz, 2015), and, on the main islands, exhibits two geographical trends, Kea and Loa, with distinct geochemical signatures (Abouchami et al., 2005, Tanaka et al., 2008, Weis et al., 2011). Although Hawai‘i is the archetypal mantle plume, it is anomalous in many of its dynamic and geochemical features. For example, intraplate lavas worldwide are dominantly alkalic in composition, reflecting lower degrees of partial melting, in comparison to Hawai‘i where ∼98% of eruptive products are of tholeiitic composition (Garcia et al., 2015). In addition, mantle plumes typically exhibit higher magmatic production at their initial arrival at the base of the lithosphere that dramatically diminishes with time, i.e. from melting the plume head to the plume tail (White, 1993, Jellinek and Manga, 2004, Kumagai et al., 2008). The volume flux of Hawaiian eruptive products, conversely, has increased ∼650% along the Northwest Hawaiian Ridge (NWHR) and an additional ∼375% during the formation of the Hawaiian Islands to an all-time high at the current locus of volcanism centered on Kilauea and Lō‘ihi volcanoes (Wessel, 2016). At the same time, mantle potential temperature has increased (Tree, 2016), along with the volcano propagation rate (i.e. the frequency that a new volcano is created as the Pacific Plate moves over the Hawaiian mantle plume; O'Connor et al., 2013). Thus, on the basis of most major physical parameters, the Hawaiian mantle plume has strengthened, an unexplained observation that is a very unusual feature among mantle plumes worldwide (Tree, 2016). No modern geochemical study has addressed this issue or determined the isotopic variation along the NWHR, to evaluate whether source changes have played a role.
The source of the Loa component in Hawaiian lavas is more enriched (higher Th/U, 208Pb*/206Pb*, and Sr isotopic ratios; lower Nd and Hf isotopic ratios) than that of the Kea component. This signature is predominately explained by the presence of subduction recycled material (Weis et al., 2011) or primordial material in the deep source (Williams et al., 2015). Lead isotopes provide the most robust tool for delineating the Loa and Kea components in Hawaiian basalts: at a given 208Pb/204Pb, Loa-trend volcanoes will have a lower 206Pb/204Pb than Kea trend volcanoes (Abouchami et al., 2005, Weis et al., 2011). Emperor Seamount lavas (85–51 Ma) are Kea-like in geochemical affinity, whereas both Kea and Loa compositions are present in lavas from the Hawaiian Islands, and furthermore are clearly distributed along two geographical trends of volcanoes (Fig. 1; Keller et al., 2000, Regelous et al., 2003, Abouchami et al., 2005, Tanaka et al., 2008, Weis et al., 2011). On the basis of only three Pb isotope analyses previously available for the NWHR, Loa geochemical compositions have been observed at only one seamount, Daikakuji, near the bend in the Hawaiian–Emperor chain (Regelous et al., 2003). It was unknown whether this is an isolated case or represents the first arrival of the Loa geochemical component (Garcia et al., 2015). Furthermore, because the Loa composition typically is associated with a more fusible source component, its presence may be linked to the dramatic increase in volcano volume (lowest at Daikakuji with 30 km3 to highest at Gardner with 540 km3; Bargar and Jackson, 1974), magmatic flux (0.4 m3/s at Daikakuji to a maximum of 4 m3/s at Gardner; Wessel, 2016), and volcanic propagation rate (Detroit to Midway 57 ± 2 km/Myr, from which increases to 80–100 km/Myr afterwards; O'Connor et al., 2013) observed along the ∼2800 km long ridge (Pertermann and Hirschmann, 2003, Garcia et al., 2015).
Lead isotopic compositions were measured on 22 shield-stage samples from 13 NWHR volcanoes spanning from ∼47 Ma at the bend to ∼7 Ma at Nīhoa (Fig. 1; Dalrymple et al., 1974, O'Connor et al., 2013). There were no Pb isotopic measurements for NWHR volcanoes younger than Daikakuji Seamount; this study fills this critical 40 million year gap. The Pb isotopic evolution of the entire Hawaiian–Emperor Seamount chain was examined to identify when the enriched Loa component appears and to assess its involvement in magmatic flux variations. Finally, we discuss the implications of these results for the Hawaiian deep mantle source and the potential contribution of material from the Pacific LLSVP to account for flux variations.
Section snippets
Geological setting and sampling
Fifty-one volcanoes erupted over ∼42 million years between the bend in the Hawaiian–Emperor chain and the Hawaiian Islands constitute the Northwest Hawaiian Ridge (NWHR; Garcia et al., 2015). We focus on shield stage tholeiitic lavas because they are most likely to record the plume source compositional variation (i.e. Loa and Kea geochemical variation), whereas the later post-shield and rejuvenated Hawaiian lavas present a uniform depleted isotopic composition regardless of the geochemical
Analytical techniques and age correction
Lead isotopic compositions of 22 Northwest Hawaiian Ridge basalts were analyzed at the Pacific Centre for Isotopic and Geochemical Research (PCIGR) at the University of British Columbia. In addition to isotopic analyses, major elements were analyzed at the University of Massachusetts (Rhodes and Vollinger, 2004) and this data is reported in Garcia et al. (2015).
Step-wise acid leaching is a necessary procedure to remove possible post-eruption alteration and/or contamination (Weis et al., 2005,
Results
Extreme Ko‘olau Makapu‘u-type Pb isotopic signatures were found only once along the NWHR; Daikakuji Seamount has the most unradiogenic 206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb among NWHR lavas (17.869, 15.418, and 37.809, respectively; Fig. 2a; Table 1). The most radiogenic lead isotopic compositions are observed for lavas from Midway in 206Pb/204Pb (18.669) and Pioneer Seamount in 207Pb/204Pb (15.493) and 208Pb/204Pb (38.206) (Fig. 2a). Samples from Daikakuji, Mokumanamana, and West Nīhoa
Role of the lithosphere in magmatic flux and Pb composition of NWHR basalts
The thickness of the lithosphere is postulated to have an effect on magmatic flux because thinner, warmer lithosphere allows higher degrees of melting than thick, cold lithosphere (White, 1993, Keller et al., 2000, Regelous et al., 2003, Niu et al., 2011). Higher degrees of melting results in lavas that are less enriched in incompatible elements with lower radiogenic Pb due to dilution of the signature of small, enriched heterogeneities by productive melting of large volumes of peridotite (
Conclusion
New high-precision Pb isotopic data closes the 2700 km (∼42 Myr) gap in the Hawaiian–Emperor chain geochemical record and shows a transition in lava composition commencing ∼20 million years after the bend. During this period, the flux of the Hawaiian plume, mantle potential temperature, and volcanic propagation rate all increased. The correlation of radiogenic Pb with magmatic flux indicates that all of these changes are related, and we suggest may be triggered by the movement of the deep
Acknowledgments
Our thanks go to Kathy Gordon and Liyan Xing for assistance analyzing Pb isotopic compositions and to Jonathan Tree for NWHR sample cataloging and rock preparation. We are also grateful to the Ocean Drilling Program, John Smith of the Hawai‘i Undersea Research Laboratory (HURL), and Alexandra Hangsterfer of Scripps Institution of Oceanography for samples analyzed in this study. This manuscript benefited greatly from reviews by Drs. Matthew Jackson and Marcel Regelous as well as discussions with
References (96)
- et al.
Derivation of large igneous provinces of the past 200 million years from long-term heterogeneities in the deep mantle
Earth Planet. Sci. Lett.
(2004) - et al.
An unusually large ULVZ at the base of the mantle near Hawaii
Earth Planet. Sci. Lett.
(2012) - et al.
Three distinct types of hotspots in the Earth's mantle
Earth Planet. Sci. Lett.
(2003) - et al.
Age of the Hawaiian–Emperor bend
Earth Planet. Sci. Lett.
(1976) - et al.
Revised age for Midway Volcano, Hawaiian volcanic chain
Earth Planet. Sci. Lett.
(1977) - et al.
Thermal convection in a heterogeneous mantle
C. R. Géosci.
(2003) - et al.
Thermally-driven mantle plumes reconcile multiple hot-spot observations
Earth Planet. Sci. Lett.
(2009) - et al.
Dynamics and internal structure of a lower mantle plume conduit
Earth Planet. Sci. Lett.
(2009) - et al.
The P-wave boundary of the large-low shear velocity province beneath the Pacific
Earth Planet. Sci. Lett.
(2014) - et al.
Petrology and geochronology of volcanic rocks from seamounts along and near the Hawaiian Ridge: implications for propagation rate of the ridge
Lithos
(1987)
Nb and Pb in oceanic basalts: new constraints on mantle evolution
Earth Planet. Sci. Lett.
The composition of the Earth
Chem. Geol.
Tracking deep mantle reservoirs with ultra-low velocity zones
Earth Planet. Sci. Lett.
Trace element characterization of USGS reference materials by HR-ICP-MS and Q-ICP-MS
Chem. Geol.
Hawaiian double volcanic chain triggered by and episodic involvement of recycled material: constraints from temporal Sr–Nd–Hf–Pb isotopic trend of the Loa-type volcanoes
Earth Planet. Sci. Lett.
High-precision analysis of Pb isotope ratios by multi-collector ICP-MS
Chem. Geol.
The distribution of geochemical heterogeneities in the source of Hawaiian shield lavas as revealed by a transect across the strike of the Loa and Kea spatial trends: East Molokai to West Molokai to Penguin Bank
Geochim. Cosmochim. Acta
Seismic evidence for a chemically distinct thermochemical reservoir in Earth's deep mantle beneath Hawaii
Earth Planet. Sci. Lett.
Lead isotopes reveal bilateral asymmetry and vertical continuity in the Hawaiian mantle plume
Nature
Spatio and temporal variability in Hawaiian hotspot volcanism induced by small-scale convection
Nat. Geosci.
Calculated volumes of individual shield volcanoes along the Hawaiian–Emperor chain
J. Res. U.S. Geol. Surv.
Temporal isotopic variations in the Hawaiian Mantle Plume: the Lanai anomaly, the Molokai fracture zone and a seawater-altered lithospheric component in Hawaiian volcanism
Mantle plumes: dynamic models and seismic images
Geochem. Geophys. Geosyst.
Lower mantle structure from paleogeographically constrained dynamic Earth models
Geochem. Geophys. Geosyst.
Origin and intraplate volcanoes from guyot heights and oceanic paleodepth
J. Geophys. Res.
Bathymetry of the emperor seamounts
The Hawaiian–Emperor Seamount Chain: Its Origin, Petrology, and Implications for Plate Tectonics
Petrography and K–Ar ages of dredged volcanic rocks from the Western Hawaiian Ridge and the Southern Emperor Seamount chain
Geol. Soc. Am. Bull.
The Hawaiian–Emperor Volcanic chain. Part I. Geologic evolution
Contributions to the petrography and geochronology of the volcanic rocks from the leeward Hawaiian islands
Geol. Soc. Am. Bull.
Petrology and K–Ar ages of dredged samples from Laysan Island and Northampton Bank volcanoes, Hawaiian Ridge, and evolution of the Hawaiian–Emperor chain: summary
Geol. Soc. Am. Bull.
Preliminary Report on Leg VII of ARIES Expedition: Geological Investigations in the Western North Pacific, July–August, 1971
Comprehensive Pb–Sr–Nd–Hf isotopic, trace element, and mineralogical characterization of mafic to ultramafic rock reference materials
Geochem. Geophys. Geosyst.
Broad plumes rooted at the base of the Earth's mantle beneath major hotspots
Nature
Origin of depleted components in basalt related to the Hawaiian hot spot: evidence from isotopic and incompatible element ratios
Geochem. Geophys. Geosyst.
Residence time of thorium, uranium and lead in the mantle with implications for mantle convection
Nature
Practical application of Pb triple spiking for correction of instrumental mass discrimination
Mineral. Mag.
Petrology, geochemistry, and geochronology of Kaua‘i lavas over 4.5 Myr: implications for the origin of rejuvenated volcanism and the evolution of the Hawaiian Plume
J. Petrol.
Petrology, geochemistry, and ages of lavas from the Northwest Hawaiian Ridge volcanoes
Continent-sized anomalous zones with low seismic velocity at the base of the Earth's mantle
Nat. Geosci.
Alteration mineralogy and the effect of acid-leaching on the Pb-isotope systematics of ocean–island basalts
Am. Mineral.
Horizontal and vertical zoning of heterogeneities in the Hawaiian mantle plume from the geochemistry of consecutive postshield volcano pairs: Kohala–Mahukona and Mauna Kea–Hualalai
Geochem. Geophys. Geosyst.
A rapid burst in hotspot motion through the interaction of tectonics and deep mantle flow
Nature
Provenance of plumes in global convection models
Geochem. Geophys. Geosyst.
Geographic boundary of the ‘Pacific Anomaly’ and its geometry and transitional structure in the north
J. Geophys. Res.
Two views of Hawaiian plume structure
Geochem. Geophys. Geosyst.
Petrogenesis of lavas from Detroit Seamount: geochemical differences between Emperor Chain and Hawaiian volcanoes
Geochem. Geophys. Geosyst.
Reykjanes ‘V’-shaped ridges originating from a pulsing and dehydrating mantle plume
Nature
Cited by (50)
An emerging plume head interacting with the Hawaiian plume tail
2023, InnovationWidespread magmatic provinces at the onset of the Sturtian snowball Earth
2022, Earth and Planetary Science LettersCitation Excerpt :For the Franklin−Irkutsk LIP of Laurentia and Siberia, the least-contaminated basalts in the regions close to the inferred plume center (e.g., Victoria Island) show a decoupling of Nd [εNd(t) =+4.4 to +11.8] and Hf [εHf(t) =+0.8 to +11.1] isotopes, with the εNd(t)-εHf(t) array lying below the Hf−Nd terrestrial array (Beard et al., 2017). The array of decoupled Hf−Nd isotopes potentially suggests that the mantle source of these mafic rocks involved recycled oceanic crust (Beard et al., 2017), similar to Hawaiian plume-originated basalts (Harrison et al., 2017; Weis et al., 2011). A plume origin is also consistent with the spatial variation in basaltic compositions of the Franklin−Irkutsk LIP (Fig. 4), which could be the result of a systematic difference in the degree of melting caused by the spatial zonation of mantle plume temperature (Campbell and Griffiths, 1990; Herzberg and Gazel, 2009).
Mantle temperature and density anomalies: The influence of thermodynamic formulation, melt, and anelasticity
2021, Physics of the Earth and Planetary InteriorsCitation Excerpt :More fundamentally, the amplitude of dT for both compositions is unrealistically large and would imply lateral variations of the mantle temperature in the range of 1150–1350 K at 130-km depth (Fig. 3g), and in the range 900–1300 K for depths 0–100 km (Fig. 3f,g). This exceeds the excess temperatures estimated by petrological studies beneath Iceland and Hawaii, the high end of which are of the order of 300–360 K (Tree, 2016; Spice et al., 2016; Harrison et al., 2017; Putirka et al., 2018). We denote dT = 300 K with a black dashed line for visual comparison in Fig. 3c.