The crustal structure beneath Mauritius from teleseismic P receiver functions: Oceanic or continental?

It has recently been suggested that the volcanic island of Mauritius may be underlain by a remnant of continental origin termed “Mauritia.” To constrain the crustal thickness beneath Mauritius, we analyzed data from 11 land stations, 10 of which were deployed recently by the RHUM‐RUM project. From the recordings, we obtained 382 P receiver functions (RFs). By applying the H‐κ stacking technique, we derive crustal thicknesses of approximately 10–15 km. We observe a considerable variation in the Vp/Vs ratio caused by a lack of clear multiples. Using forward modeling of RFs, we show that the lack of clear multiples can be explained by a transitional Moho, where the velocity increases gradually. The modeling further indicates that the thickness of this gradient zone is estimated to be approximately 10 km. We argue that our findings suggest oceanic crust thickened by crustal underplating due to the mantle plume currently located beneath La Réunion.

[1]  M. Wiedenbeck,et al.  First Archean Zircons Found in Oceanic Crustal Rocks of Mauritius , 2016 .

[2]  G. Barruol,et al.  Crustal and uppermost mantle structure variation beneath La Réunion hotspot track , 2015 .

[3]  J. Hammond,et al.  The extent of continental crust beneath the Seychelles , 2013 .

[4]  G. Barruol,et al.  Investigating La Réunion Hot Spot From Crust to Core , 2013 .

[5]  M. Whitehouse,et al.  Anomalous sulphur isotopes in plume lavas reveal deep mantle storage of Archaean crust , 2013, Nature.

[6]  F. Corfu,et al.  A Precambrian microcontinent in the Indian Ocean , 2013 .

[7]  R. Kind,et al.  Seismic receiver functions and the lithosphere–asthenosphere boundary , 2012 .

[8]  E. Lepekhina,et al.  Younger and older zircons from rocks of the oceanic lithosphere in the Central Atlantic and their geotectonic implications , 2010 .

[9]  S. S. Rai,et al.  Magmatic underplating of crust beneath the Laccadive Island, NW Indian Ocean , 2010 .

[10]  S. Solomon,et al.  Underplating of the Hawaiian Swell: evidence from teleseismic receiver functions , 2010 .

[11]  R. White,et al.  Influence of the Iceland mantle plume on oceanic crust generation in the North Atlantic , 2008 .

[12]  K. Priestley,et al.  Crustal structure of Iceland and Greenland from receiver function studies , 2007 .

[13]  M. Weber,et al.  Deep origin of the Hawaiian tilted plume conduit derived from receiver functions , 2006 .

[14]  Jérôme Vergne,et al.  Seismological evidence for crustal‐scale thrusting in the Zagros mountain belt (Iran) , 2006 .

[15]  Jeffrey Park,et al.  Hunting for oceanic island Moho , 2005 .

[16]  K. Uto,et al.  Systematic Variation of Sr-, Nd- and Pb- Isotopes with Time in Lavas of Mauritius, Reunion Hotspot , 2004 .

[17]  J. Mahoney,et al.  Geochemistry of Lavas from Mauritius, Indian Ocean: Mantle Sources and Petrogenesis , 2003 .

[18]  K. Uto,et al.  Noble gas study of the Reunion hotspot: evidence for distinct less-degassed mantle sources , 2001 .

[19]  Frederik Tilmann,et al.  P-wave velocity structure of the uppermost mantle beneath Hawaii from traveltime tomography , 2001 .

[20]  J. Bialas,et al.  Crustal architecture and deep structure of the Ninetyeast Ridge hotspot trail from active‐source ocean bottom seismology , 2001 .

[21]  M. Bostock,et al.  Modelling teleseismic waves in dipping anisotropic structures , 2000 .

[22]  Hiroo Kanamori,et al.  Moho depth variation in southern California from teleseismic receiver functions , 2000 .

[23]  Charles J. Ammon,et al.  Iterative deconvolution and receiver-function estimation , 1999 .

[24]  J. Díaz,et al.  Perturbation to the lithosphere along the hotspot track of La Réunion from an offshore-onshore seismic transect , 1999 .

[25]  Y. Hello,et al.  Spatial distribution of hotspot material added to the lithosphere under La Réunion, from wide‐angle seismic data , 1999 .

[26]  F. Haubrich,et al.  Palaeozoic and Proterozoic zircons from the Mid-Atlantic Ridge , 1998, Nature.

[27]  Gabi Laske,et al.  CRUST 5.1: A global crustal model at 5° × 5° , 1998 .

[28]  D. Caress,et al.  Seismic imaging of hotspot-related crustal underplating beneath the Marquesas Islands , 1995, Nature.

[29]  P. Wessel.  Observational constraints on models of the Hawaiian Hot Spot Swell , 1993 .

[30]  D. Lindwall.  Old Pacific crust near Hawaii: A seismic view , 1991 .

[31]  A. Watts,et al.  Crustal structure, flexure, and subsidence history of the Hawaiian Islands , 1989 .

[32]  D. Lindwall.  A two-dimensional seismic investigation of crustal structure under the Hawaiian Islands near Oahu and Kauai , 1988 .

[33]  P. Buhl,et al.  A multichannel seismic study of lithospheric flexure across the Hawaiian–Emperor seamount chain , 1985, Nature.

[34]  J. J. Zucca,et al.  Crustal structure of the southeast flank of Kilauea Volcano, Hawaii, from seismic refraction measurements , 1980 .

[35]  R. Crosson,et al.  Seismic velocity structure below the island of Hawaii from local earthquake data , 1979 .

[36]  A. N. Baxter.  Geochemistry and petrogenesis of primitive alkali basalt from Mauritius, Indian Ocean , 1976 .

[37]  A. Waltham,et al.  The Geology and Mineral Resources of Yorkshire , 1975 .

[38]  A. N. Baxter.  Petrology of the Older Series lavas from Mauritius, Indian Ocean , 1975 .

[39]  G. Sutton,et al.  Crustal Structure of the Hawaiian Archipelago, Northern Melanesia, and the Central Pacific Basin by Seismic Refraction Methods* , 1973 .

[40]  I. Mcdougall,et al.  Isotopic Dating and Geomagnetic Polarity Studies on Volcanic Rocks from Mauritius, Indian Ocean , 1969 .

[41]  G. Johnson,et al.  Mascarene Plateau, Western Indian Ocean , 1967 .

[42]  T. Francis,et al.  The crustal structure of the Seychelles bank , 1964 .

[43]  D. D. Pollard,et al.  Seismic Investigations of Seychelles and Saya de Malha Banks, Northwest Indian Ocean , 1963, Science.

[44]  M. Bostock.  Theory and Observations - Seismology and the Structure of the Earth: Teleseismic Body-Wave Scattering and Receiver-Side Structure , 2015 .

[45]  M. Bostock.  Theory and Observations – Teleseismic Body-Wave Scattering and Receiver-Side Structure , 2007 .