Abstract
Electromagnetic measurements have demonstrated that the lower continental crust has remarkable electrical anomalies of high conductivity and electrical anisotropy on a global scale (probably with some local exceptions), but their origin is a long-standing and controversial problem. Typical electrical properties of the lower continental crust include: (1) the electrical conductivity is usually 10−4 to 10−1 S/m; (2) the overlying shallow crust and underlying upper mantle are in most cases less conductive; (3) the electrical conductivity is statistically much higher in Phanerozoic than in Precambrian areas; (4) horizontal anisotropy has been resolved in many areas; and (5) in some regions there appear to be correlations between high electrical conductivity and other physical properties such as seismic reflections. The explanation based on conduction by interconnected, highly conductive phases such as fluids, melts, or graphite films in grain boundary zones has various problems in accounting for geophysically resolved electrical conductivity and other chemical and physical properties of the lower crust. The lower continental crust is dominated by mafic granulites (in particular beneath stable regions), with nominally anhydrous clinopyroxene, orthopyroxene, and plagioclase as the main assemblages, and the prevailing temperatures are mostly 700–1,000°C as estimated from xenolith data, surface heat flow, and seismic imaging. Pyroxenes have significantly higher Fe content in the lower crust than in the upper mantle (peridotites), and plagioclase has higher Na content in the lower crust than in the shallow crust (granites). Minerals in the lower continental crust generally contain trace amounts of water as H-related point defects, from less than 100 to more than 1,000 ppm H2O (by weight), with concentrations usually higher than those in the upper mantle. Observations of xenolith granulites captured by volcano-related eruptions indicate that the lower continental crust is characterized by alternating pyroxene-rich and plagioclase-rich layers. Experimental studies on typical lower crustal minerals have shown that their electrical conductivity can be significantly enhanced by the higher contents of Fe (for pyroxenes), Na (for plagioclase), and water (for all minerals) at thermodynamic conditions corresponding to the lower continental crust, e.g., to levels comparable to those measured by geophysical field surveys. Preferred orientation of hydrous plagioclase, e.g., due to ductile flow in the deep crust, and alternating mineral fabrics of pyroxene-rich and plagioclase-rich layers can lead to substantial anisotropy of electrical conductivity. Electrical conductivity properties in many regions of the lower continental crust, especially beneath stable areas, can mostly be accounted for by solid-state conduction due to the major constituents; other special, additional conduction mechanisms due to grain boundary phases are not strictly necessary.
Similar content being viewed by others
References
Ague JJ (2003) Fluid flow in the deep crust. In: Rudnick RL (ed) The crust. Elsevier, Oxford, pp 195–228
Alabi AO, Canfield RA, Gough DI (1975) North American central plains conductivity anomaly. Geophys J R Astron Soc 43:815–833
Alfonso P, Melgarejo C (2003) Geochemistry of feldspars and muscovite in granitic pegmatite from the Cap de Creus feild, Catalonia, Spain. Can Mineral 41:103–116
Al-Mishwat AT, Nasir SJ (2004) Composition of the lower crust of the Arabian Plate: a xenolith perspective. Lithos 72:45–72
Artemieva IM (2009) The continental lithosphere: reconciling thermal, seismic and petrologic data. Lithos 109:23–46
Ayres M, Harris N, Vance D (1997) Possible constraints on anatectic melt residence times from accessory mineral dissolution rates: an example from Himalayan leucogranites. Mineral Mag 61:29–36
Bahr K, Bantin M, Jantos C, Schneider E, Storz W (2000) Electrical anisotropy from electromagnetic array data: implications for the conduction mechanism and for distortion at long periods. Phys Earth Planet Inter 119:237–257
Bailey RC, Craven JA, Macnae JC, Polzer BD (1989) Imaging of deep fluids in Archaean crust. Nature 340:136–138
Bohlen SR, Mezger K (1989) Origin of granulite terranes and the formation of the lowermost continental crust. Science 244:326–329
Brace WF (1971) Resistivity of saturated crustal rocks up to 40 km based on laboratory measurements. In: Heacock JG (ed) Structure and physical properties of the earth’s crust. AGU Geophys Monogr Ser, Washington, DC, pp 243–255
Buerschaper RA (1944) Thermal and electrical conductivity of graphite and carbon at low temperatures. J Appl Phys 15:452–454
Campbell IH, Taylor SR (1985) No water, no granites—no oceans, no continents. Geophys Res Lett 10:1061–1064
Cesare B, Meli S, Nodari L, Russo U (2005) Fe3+ reduction during biotite melting in graphitic metapelites: another origin of CO2 in granulites. Contrib Mineral Petrol 149:129–140
Chen CY, Frey FA, Song Y (1989) Evolution of the upper mantle beneath southeast Australia: geochemical evidence from peridotite xenoliths in Mount Leura basanite. Earth Planet Sci Lett 93:195–209
Chen S, O’Reilly SY, Zhou X, Griffin WL, Zhang G, Sun M, Feng J, Zhang M (2001) Thermal and petrological structure of the lithosphere beneath Hannuoba, Sino-Korean Craton, China: evidence from xenoliths. Lithos 56:267–301
Chen SS, Hiraga T, Kohlstedt DL (2006) Water weakening of clinopyroxene in the dislocation creep regime. J Geophys Res 111:B08203. doi:10.1029/2005JB003885
Christensen NI, Mooney WD (1995) Seismic velocity structure and composition of the continental crust—a global view. J Geophys Res 100:9761–9788
Clemens JD, Droop GTR, Stevens G (1997) High-grade metamorphism, dehydration and crustal melting: a reinvestigation based on new experiments in the silica-saturated portion of the system KAlO2-MgO-SiO2–H2O-CO2 at P ≤ 1.5 GPa. Contrib Mineral Petrol 129:308–325
Connolly JAD (1997) Devolatilization-generated fluid pressure and deformation-propagated fluid flow during prograde regional metamorphism. J Geophys Res 102:18149–18173
Copley A, Avouac J-P, Wernicke BP (2011) Evidence for mechanical coupling and strong Indian lower crust beneath southern Tibet. Nature 472:79–81
Cull J (1985) Magnetotelluric soundings over a Precambrian contact in Australia. Geophys J R Astron Soc 80:661–675
Dai L, Karato SI (2009) Electrical conductivity of orthopyroxene: implications for the water content of the asthenosphere. Proc Jpn Acad Ser B 85:466–475
Dai BZ, Jiang SY, Jiang YH, Zhao KD, Liu DY (2008) Geochronology, geochemistry and Hf-Sr-Nd isotopic compositions of Huziyan mafic xenoliths, southern Hunan Province, South China: petrogenesis and implications for lower crust evolution. Lithos 102:65–87
Demouchy S, Jacobsen SD, Gaillard F, Stern CR (2006) Rapid magma ascent recorded by water diffusion profiles in mantle olivine. Geology 34:429–432
Dessai AG, Markwick A, Vaselli O, Downes H (2004) Granulite and pyroxenite xenoliths from the Deccan Trap: insight into the nature and composition of the lower lithosphere beneath cratonic India. Lithos 78:263–290
Dixon JE, Leist L, Langmuir CH, Schilling JG (2002) Recycled dehydrated lithosphere observed in plume-influenced mid-ocean-ridge basalt. Nature 420:385–389
Dobosi G, Kempton PD, Downes H, Embey-Isztin A, Thirlwall M, Greenwood P (2003) Lower crustal granulite xenoliths from the Pannonian Basin, Hungary, Part 2: Sr-Nd-Pb-Hf and O isotope evidence for formation of continental lower crust by tectonic emplacement of oceanic crust. Contrib Mineral Petrol 144:671–683
Downes H, Peltonen P, Manttari I, Sharkov EV (2002) Properozoic zircon ages from lower crustal granulite xenoliths, Kola Peninsula, Russia: evidence for crustal growth and reworking. J Geol Soc 159:485–488
Drury MJ, Hyndman RD (1979) The electrical resistivity of oceanic basalts. J Geophys Res 18:4537–4545
Duba AG, Shankland TJ (1982) Free carbon and electrical conductivity in the Earth’s mantle. Geophys Res Lett 9:1271–1274
Duba AG, Heikamp S, Meurer W, Nover H, Will G (1994) Evidence from borehole samples for the role of accessory minerals in lower-crustal conductivity. Nature 367:59–61
Fodor RV, Sial AN, Gandhok G (2002) Petrology of spinel peridotite xenoliths from northeastern Brazil: lithosphere with a high geochemal gradient imparted by Fernando de Noronha plume. J S Am Earth Sci 15:199–214
Fountain DM, Arculus R, Kay RW (1992) Continental lower crust. Elsevier, Amsterdam
Frost DJ, McCammon CA (2008) The redox state of the earth’s mantle. Annu Rev Earth Planet Sci 36:389–420
Frost BR, Fyfe WS, Tazaki K, Chan T (1989) Grain-boundary graphite in rocks and implications for high electrical conductivity in the lower crust. Nature 340:134–136
Glover PWJ (1996) Graphite and electrical conductivity in the lower continental crust: a review. Phys Chem Earth 21:279–287
Glover PWJ, Adam A (2008) Correlation between crustal high conductivity zones and seismic activity and the role of carbon during shear deformation. J Geophys Res 113:B12210. dio: 12210.11029/12008JB005804
Glover PWJ, Vine FJ (1992) Electrical conductivity of carbon-bearing granulite at raised temperatures and pressures. Nature 360:723–726
Glover PWJ, Vine FJ (1994) Electrical conductivity of the continental crust. Geophys Res Lett 21:2357–2360
Gough DI (1986) Seismic reflectors, conductivity, water and stress in the continental crust. Nature 323:143–144
Gough DI (1992) Electromagnetic exploration for fluids in the Earth’s crust. Earth-Sci Rev 32:3–18
Greenberg JK (1981) Characteristics and origin of Egyptian younger granites: summary. GSA Bull 92:224–232
Guseinov AA, Gargatsev IO (2003) The temperature effect on the electrical conductivity of muscovites. Izv Phys Solid Earth 39:82–90
Haak V, Hutton VRS (1986) Electrical conductivity in the continental lower crust. In: Dawson JB, Hall J, Wedepohl KH (eds) The nature of the lower continental crust. Geological Society of London, Special Publications 24, pp 35–49
Hacker BR, Gnos E, Ratschbacher L, Grove M, McWilliams M, Sobolev SV, Jiang W, Wu Z (2000) Hot and dry deep crustal xenoliths from Tibet. Science 287:2463–2466
Hawkesworth CJ, Kemp AIS (2006) Evolution of the continental crust. Nature 443:811–817
Hermance JF (1979) The electrical conductivity of materials containing partial melt. Geophys Res Lett 6:613–616
Hinze E, Will G, Cemic L (1981) Electrical conductivity measurements on synthetic olivines and on olivine, enstatite and diopside from Dreiser Weiher, Eifel (Germany) under defined thermodynamic activities as a function of temperature and pressure. Phys Earth Planet Inter 25:245–254
Holbrook WS, Mooney WD, Christensen NI (1992) The seismic velocity structure of the deep continental crust. In: Fountain DM, Arculus RW Kay R (eds) Continental lower crust. Elsevier, Amsterdam, pp 1–44
Holtta P, Huhma H, Manttari I, Peltonen P, Juhanoja J (2000) Petrology and geochemistry of mafic granulite xenoliths from the Lahtojoki kimberlite pipe, eastern Finland. Lithos 51:109–133
Huang XL, Xu YG, Liu DY (2004) Geochronology, petrology and geochemistry of the granulite xenoliths from Nushan, east China: implication for a heterogeneous lower crust beneath the Sino-Korean Craton. Geochim Cosmochim Acta 68:127–149
Huebner JS, Dillenburg RG (1995) Impedance spectra of hot, dry silicate minerals and rock: qualitative interpretation of spectra. Am Mineral 80:46–64
Huebner JS, Voigt DE (1988) Electrical conductivity of diopside: evidence for oxygen vacancies. Am Mineral 73:1235–1254
Hyndman RD, Shearer PM (1989) Water in the lower continental crust: modelling magnetotelluric and seismic reflection results. Geophys J Int 98:343–365
Hyndman RD, Vanyan LL, Marquis G, Law LK (1993) The origin of electrically conductive lower continental crust: saline water or graphite? Phys Earth Planet Inter 81:325–344
Ingrin J, Liu J, Xia Q-K, Deloule E, Gregoire M (2011) Water content of lithospheres deduced from xenoliths: the example of Kerguelen Islands and South African craton. Mineral Mag 75:1084
Ionov DA, Prikhod’ko VS, O’Reilly SY (1995) Peridotite xenoliths in alkali basalts from the Sikhote-Alin, southeastern Siberia, Russia: trace-element signatures of mantle beneath a convergent continental margin. Chem Geol 120:275–294
Johnson EA, Rossman GR (2004) A survey of hydrous species and concentrations in igneous feldspars. Am Mineral 89:586–600
Jones AG (1987) MT and reflection: an essential combination. Geophys J R Astron Soc 898:7–18
Jones MQW (1988) Heat flow in the Witwatersrand basin and environs and its significance for the South African shield geotherm and lithosphere thickness. J Geophys Res 93:3243–3260
Jones AG (1992) Electrical properties of the lower continental crust. In: Fountain DM, Arculus RJ, Kay RW (eds) Continental lower crust. Elsevier, Amsterdam, pp 81–143
Jones AG (1993) Electromagnetic images of modern and ancient subduction zones. Tectonophysics 219:29–45
Karato S-I, Jung H (2003) Effects of pressure on high-temperature dislocation creep in olivine. Philos Mag 83:401–414
Kay RW, Kay SM (1991) Creation and destruction of lower continental crust. Geol Rundsch 80:259–278
Kellett RL, Mareschal M, Kurtz RD (1992) A model of lower crustal electrical anisotropy for the Pontiac Subprovince of the Canadian Shield. Geophys J Int 111:141–150
Kempton PD, Harmon RS, Hawkesworth CJ, Moorbath S (1990) Petrology and geochemistry of lower crustal granulites from the Geronimo Volcanic Field, southeastern Arizona. Geochim Cosmochim Acta 54:3401–3426
Kempton PD, Downes H, EmbeyIsztin A (1997) Mafic granulite xenoliths in neogene alkali basalts from the Western Pannonian Basin: insights into the lower crust of a collapsed orogen. J Petrol 38:941–970
Kenkmann T, Dresen G (2002) Dislocation microstructure and phase distribution in a lower crustal shear zone–an example from the Ivrea-Zone, Italy. Int J Earth Sci 91:445–458
Keppler H, Bolfan-Casanova N (2006) Thermodynamics of water solubility and partitioning. In: Keppler H, Smyth JR (eds) Water in nominally anhydrous minerals. Mineralogical Society of America, Washington, DC, pp 193–230
Khitarov N, Slutskii B (1965) The effect of pressure on the melting temperatures of albite and basalt (based on electronconductivity measurements). Geochem Int 2:1034–1041
Kohlstedt DL (2006) The role of water in high-temperature rock deformation. In: Keppler H, Smyth JR (eds) Water in nominally anhydrous minerals. Reviews in Mineralogy and Geochemistry, Mineralogical Society of America, Washington, DC, pp 377–396
Kohlstedt DL, Evans B, Mackwell S (1995) Strength of the lithosphere: constrains imposed by laboratory experiments. J Geophys Res 100:17587–17602
Korja T, Hjelt SE (1993) Electromagnetic studies in the fennoscandian shield—electrical conductivity of Precambrian crust. Phys Earth Planet Inter 81:107–138
Lamb WM, Valley JW (1987) Post-metamorphic CO2-rich fluid inclusions in granulites. Contrib Mineral Petrol 96:485–495
Lee CD, Vine FJ, Ross RG (1983) Electrical conductivity models for the continental crust based on laboratory measurements on high grade metamorphic rocks. Geophys J R Astron Soc 72:353–371
Leibecker J, Gatzemeier A, Honig M, Kuras O, Soyer W (2002) Evidence of electrical anisotropic structures in the lower crust and the upper mantle beneath the Rhenish Shield. Earth Planet Sci Lett 202:289–302
Liu YS, Gao S, Jin SY, Hu SH, Sun M, Zhao ZB, Feng JL (2001) Geochemistry of lower crustal xenoliths from Neogene Hannuoba basalt, North China craton: implications for petrogenesis and lower crustal composition. Geochim Cosmochim Acta 65:2589–2604
Lucassen F, Lewerenz S, Franz G, Viramonte J, Mezger K (1999) Metamorphism, isotopic ages and composition of lower crustal granulite xenoliths from the Cretaceous Salta Rift, Argentina. Contrib Mineral Petrol 134:325–341
Mackwell SJ, Zimmerman ME, Kohlstedt DL (1998) High-temperature deformation of dry diabase with application to tectonics on Venus. J Geophys Res 103:975–984
Mareschal M, Fyfe WS, Percival J, Chan T (1992) Grain-boundary graphite in Kapuskaing gneisses and implications for lower-crustal conductivity. Nature 357:674–676
Markl G, Bucher K (1998) Composition of fluids in the lower crust inferred from metamorphic salt in lower crustal rocks. Nature 391:781–783
Markwick AJW, Downes H (2000) Lower crustal granulite xenoliths from the Arkhangelsk kimberlite pipes: petrological, geochemical and geophysical results. Lithos 51:135–151
Marquis G, Hyndman RD (1992) Geophysical support for aqueous fluids in the deep crust: seismic and electrical relationships. Geophys J Int 110:91–105
McCammon C (2005) The paradox of mantle redox. Science 308:807–808
Mcguire AV, Stern RJ (1993) Granulite xenoliths from Western Saudi-Arabia—the lower crust of the Late Precambrian Arabian-Nubian Shield. Contrib Mineral Petrol 114:395–408
McKenzie D, Nimmo F, Jackson JA, Gans PB, Miller EL (2000) Characteristics and consequences of flow in the lower crust. J Geophys Res 105:11029–11046
Meissner R, Mooney W (1998) Weakness of the lower continental crust: a condition for delamination, uplift, and escape. Tectonophysics 296:47–60
Mercier JCC, Nicolas A (1975) Textures and fabrics of upper mantle peridotites as illustrated by xenoliths from basalts. J Petrol 16:454–487
Merzer AM, Klemperer SL (1992) High electrical conductivity in a model lower crust with unconnected, conductive, seismically reflective layers. Geophys J Int 108:895–905
Moecher DP (1993) Scapolite phase-equilibria and carbon isotopes—constraints on the nature and distribution of CO2 in the lower continental-crust. Chem Geol 108:163–174
Montanini A, Harlov D (2006) Petrology and mineralogy of granulite-facies mafic xenoliths (Sardinia, Italy): evidence for KCl metasomatism in the lower crust. Lithos 92:588–608
Mooney WD, Meissner R (1992) Multi-genetic origin of crustal reflectivity: a review of seismic reflection profiling of the continental lower crust and Moho. In: Fountain DM, Arculus R, Kay RW (eds) Continental lower crust. Elsevier, New York, pp 45–80
Newton RC, Smith JV, Windley BF (1980) Carbonic metamorphism, granulites and crustal growth. Nature 288:45–50
Nyblade AA, Pollack HN (1993) A global analysis of heat flow from Precambrian terrains: implications for the thermal structure of Archean and Proterozoic lithosphere. J Geophys Res 98:12207–12218
Olhoeft GR (1981) Electrical properties of granite with implications for the lower crust. J Geophys Res 86:931–936
Park RG (1988) Geological structures and moving plates. Chapman & Hall, New York, p 337
Pearson NJ, O’Reilly SY, Griffin WL (1995) The crust-mantle boundary beneath cratons and craton margins: a transect across the south-west margin of the Kaapvaal craton. Lithos 36:257–287
Pham VN, Boyer D, Therme P, Yuan XC, Li L, Jin GY (1986) Partial melting zones in the crust in southern Tibet from magnetotelluric results. Nature 319:310–314
Ranalli G, Murphy DC (1987) Rheological stratification of the lithosphere. Tectonophysics 132:281–295
Rasmussen TM (1988) Magnetotellurics in southwestern Sweden: evidence for electrical anisotropy in the lower crust? J Geophys Res 93:7897–7907
Ray R, Shukla AD, Sheth HC, Ray JS, Duraiswami RA, Vanderkluysen L, Rautela CS, Mallik J (2008) Highly heterogeneous Precambrian basement under the central Deccan Traps, India: direct evidence from xenoliths in dykes. Gondwana Res 13:375–385
Reynard B, Mibe K, Van de Moortele B (2011) Electrical conductivity of the serpentinised mantle and fluid flow in subduction zones. Earth Planet Sci Lett 307:387–394
Roberts JJ (2002) Electrical properties of microporous rock as a function of saturation and temperature. J Appl Phys 91:1687–1694
Roberts SJ, Ruiz J (1989) Geochemistry of exposed granulite facies terrains and lower crustal xenoliths in Mexico. J Geophys Res 94:7961–7974
Rollinson HR, Tarney J (2005) Adakites—the key to understanding LILE depletion in granulites. Lithos 79:61–81
Romano C, Poe BT, Kreidie N, McCammon C (2006) Electrical conductivities of pyrope-almandine garnets up to 19 GPa and 1700°C. Am Mineral 91:1371–1377
Rudnick RL, Fountain DM (1995) Nature and composition of the continental crust: a lower crustal perspective. Rev Geophys 33:267–309
Rudnick RL, Gao S (2003) Composition of the continental crust. In: Rudnick RL (ed) Treatise on geochemistry: the crust. Elsevier, Oxford, pp 1–64
Rudnick RL, Taylor SR (1987) The composition and petrogenesis of the lower crust: a xenolith study. J Geophys Res 92:13981–14005
Rudnick RL, McDonough WF, Mcculloch MT, Taylor SR (1986) Lower crustal xenoliths from Queensland, Austrilia: evidence for deep crustal assimilation and fractionation of continental basalts. Geochim Cosmochim Acta 50:1099–1115
Rudnick RL, Gao S, Ling WL, Liu YS, McDonough WF (2004) Petrology and geochemistry of spinel peridotite xenoliths from Hannuoba and Qixia, North China craton. Lithos 77:609–637
Rybacki E, Dresen G (2000) Dislocation and diffusion creep of synthetic anorthite aggregates. J Geophys Res 105:26017–26036
Schmidberger SS, Francis D (1999) Nature of the mantle roots beneath the North American craton: mantle xenolith evidence from Somerset Island kimberlites. Lithos 48:195–216
Schulgasser K (1977) Bounds on the conductivity of statistically isotropic polycrystals. J Phys C Solid State Phys 10:407–417
Segall P, Simpson C (1986) Nucleation of ductile shear zones on dilatant fractures. Geology 14:56–59
Shankland TJ (1975) Electrical conduction in rocks and minerals: parameters for interpretation. Phys Earth Planet Inter 10:209–219
Shankland TJ, Ander ME (1983) Electrical conductivity, temperatures and fluids in the lower crust. J Geophys Res 88:527–538
Simpson F (2001) Fluid trapping at the brittle-ductile transition re-examined. Geofluids 1:123–136
Stesky RS, Brace WF (1973) Eletrical conductivity of serpentinised rocks to 6 kbars. J Geophys Res 98:4301–4310
Stracke A, Bourdon B, McKenzie D (2006) Melt extraction in the Earth’s mantle: constraints from U-Th-Pa-Ra studies in oceanic basalts. Earth Planet Sci Lett 244:97–112
Taylor SR, McLennan SM (1985) The continental crust: its composition and evolution. Blackwell, Boston
Taylor SR, Mclennan SM (1995) The geochemical evolution of the continental crust. Rev Geophys 33:241–265
Teng FZ, Rudnick RL, McDonough WF, Gao S, Tomascak PB, Liu YS (2008) Lithium isotopic composition and concentration of the deep continental crust. Chem Geol 255:47–59
Tyburczy JA (2007) Properties of rocks and minerals—the electrical conductivity of rocks, minerals and the Earth. In: Davice GD (ed) Mineral physics. Elsevier, Amsterdam, pp 631–642
Ulianov A, Kalt A (2006) Mg-Al sapphirine- and Ca-Al hibonite-bearing granulite xenoliths from the Chyulu hills volcanic field, Kenya. J Petrol 47:901–927
Unsworth MJ, Jones AG, Wei W, Marquis G, Gokarn SG, Spratt JE, the INDEPTH-MT team (2005) Crustal rheology of the Himalaya and Southern Tibet inferred from magnetotelluric data. Nature 438:78–81
Viljoen F, Dobbe R, Smit B (2009) Geochemical processes in peridotite xenoliths from the Premier diamond mine, South Africa: evidence for the depletion and refertilisation of subcratonic lithosphere. Lithos 112S:1133–1142
Wang X, Wang T, Haapala I, Lu X (2002) The Shahewan rapakivi-textured granite—quartz monzonite pluton, Qinling orogen, central China: mineral composition and petrogenetic significance. Bull Geol Soc Finland 74:133–146
Wannamaker PE (1986) Electrical conductivity of water undersaturated crustal melting. J Geophys Res 91:6321–6327
Warner M (2004) Free water and seismic reflectivity in the lower continental crust. J Geophys Eng 1:88–101
Watson EB, Brenan JM (1987) Fluids in the lithosphere, 1. Experimentally determined wetting characteristics of CO2–H2O fluids and their implications for fluid transport, host-rock physical properties and fluid inclusion formation. Earth Planet Sci Lett 85:497–515
Watson HC, Roberts JJ, Tyburczy JA (2010) Effect of conductive impurities on electrical conductivity in polycrystalline olivine. Geophys Res Lett 37:L02302. doi:02310.01029/02009GL041566
Wei W, Unsworth MJ, Jones AG, Booker J, Tan H, Nelson D, Chen L, Li S, Solon K, Bedrosian P, Jin S, Deng M, Ledo JJ, Kay D, Roberts B (2001) Detection of widespread fluids in the Tibetan crust by magnetotelluric studies. Science 292:716–718
White SH, Burrows SE, Carreras J, Shaw ND, Humphreys FJ (1980) On mylonites in ductile shear zones. J Struct Geol 2:175–187
Xia Q-K, Yang X-Z, Deloule E, Sheng Y-M, Hao Y-T (2006) Water in the lower crustal granulite xenoliths from Nushan, eastern China. J Geophys Res 111. doi:10.1029/2006JB004296
Xu Y, Shankland TJ, Poe BT (2000) Laboratory-based electrical conductivity in the Earth’s mantle. J Geophys Res 105:27865–27875
Yang X-Z (2008) Water content and H-O-Li isotopes in lower crustal granulite minerals. PhD thesis, University of Science and Technology of China (Hefei, China) and Institut National Polytechnique de Lorraine (Nancy, France), p 247
Yang X (2011) Orientation-related electrical conductivity of hydrous olivine, clinopyroxene and plagioclase and implications for the structure of the lower continental crust and uppermost mantle. Earth Planet Sci Lett (in review)
Yang X-Z, Deloule E, Xia Q-K, Fan Q-C, Feng M (2008a) Water contrast between Precambrian and Phanerozoic continental lower crust in eastern China. J Geophys Res 113:B08207. doi:08210.01029/02007JB005541
Yang X-Z, Xia Q-K, Deloule E, Dallai L, Fan Q-C, Feng M (2008b) Water in minerals of continental lithospheric mantle and overlying lower crust: a comparative study of peridotite and granulite xenoliths from the North China Craton. Chem Geol 256:33–45
Yang X, Keppler H, McCammon C, Ni H (2011a) Electrical conductivity of orthopyroxene and plagioclase in the lower crust. Contrib Mineral Petrol. doi:10.1007/s00410-00011-00657-00419
Yang X, Keppler H, McCammon C, Ni H, Xia Q, Fan Q (2011b) The effect of water on the electrical conductivity of lower crustal clinopyroxene. J Geophys Res 116:B04208. doi:10.1029/2010JB008010
Yardley BWD, Valley JW (1997) The petrologic case for a dry lower crust. J Geophys Res 102:12723–12785
Zhou X, Sun M, Zhang G, Chen S (2002) Continental crust and lithospheric mantle interaction beneath North China: isotopic evidence from granulite xenoliths in Hannuoba, Sino-Korean craton. Lithos 62:111–124
Acknowledgments
Completion of this manuscript benefited greatly from the projects that I have carried out during the past ~6 years. Fruitful discussions with many colleagues and geoscientists from a range of disciplines, too many to be listed here, helped to clarify many issues. Constructive comments from Shun-ichiro Karato greatly improved the manuscript. This work was supported by the Natural Science Foundation of China (40903016) and the Alexander von Humboldt Foundation.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Yang, X. Origin of High Electrical Conductivity in the Lower Continental Crust: A Review. Surv Geophys 32, 875–903 (2011). https://doi.org/10.1007/s10712-011-9145-z
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10712-011-9145-z