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Geochemical variations in Andean basaltic and silicic lavas from the Villarrica-Lanin volcanic chain (39.5° S): an evaluation of source heterogeneity, fractional crystallization and crustal assimilation

Abstract

At 39.5° S in the southern volcanic zone of the Andes three Pleistocene-recent stratovolcanoes, Villarrica, Quetrupillan and Lanin, form a trend perpendicular to the strike of the Andes, 275 to 325 km from the Peru-Chile trench. Basalts from Villarrica and Lanin are geochemically distinct; the latter have higher incompatible element abundances and La/Sm but lower Ba/La and alkali metal/La ratios. These differences are consistent with our previously proposed models involving: a) a west to east decrease in an alkali metal-rich, high Ba/La slab-derived component which causes an across strike decrease in degree of melting; or b) a west to east increase in the contamination of subduction-related magma by enriched subcontinental lithospheric mantle. Silicic and mafic lavas from the stratovolcanoes have overlapping Sr, Nd and O isotopic ratios. Silicic lavas also have geochemical differences that parallel those of their associated basalts, e.g., rhyolite from Villarrica has lower La/Sm and incompatible element contents than high-SiO2 andesite from Lanin. At each volcano the most silicic lavas can be modelled by closed system fractional crystallization while andesites are best explained by magma mixing. Apparently crustal contamination was not an important process in deriving the evolved lavas. Basaltic flows from small scoria cones, 20–35 km from Villarrica volcano have high incompatible element contents and low Ba/La, like Lanin basalts, but trend to higher K/Rb (356–855) and lower 87Sr/ 86Sr (0.70361–0.70400) than basalts from either stratovolcano. However all basalts have similar Nd, Pb and O isotope ratios. The best explanation for the unique features of the cones is that the sources of SVZ magmas, e.g., slab-derived fluids or melts of the subcontinental lithospheric mantle, have varying alkali metal and radiogenic Sr contents. These heterogeneities are not manifested in stratovolcano basalts because of extensive subcrustal pooling and mixing. This model is preferable to one involving crustal contamination because it can account for variable Sr isotope ratios and uniform Nd and Pb isotope ratios among the basalts, and the divergence of the cones from across-strike geochemical trends defined by the stratovolcanoes.

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References

  1. Baker DR, Eggler DH (1987) Compositions of anhydrous and hydrous melts coexisting with plagioclase, augite and olivine or low-Ca pyroxene form 1 atm to 8 kbar: application to the Aleutian volcanic center of Atka. Am Mineral 72:12–28

  2. Barazangi M, Isacks BL (1976) Spatial distribution of earthquakes and subduction of the Nazca Plate beneath South America. Geology 4:686–692

  3. Bevis M, Isacks BL (1984) Hypocentral trend surface analysis: probing the geometry of Benioff zones. J Geophys Res 89:6153–6170

  4. Crecraft HR, Nash WP, Evans SH (1981) Late Cenozoic volcanism at Twin Peaks, Utah: geology and petrology. J Geophys Res 86:10303–10320

  5. Dasch EJ (1981) Lead isotopic composition of metalliferous sediments from the Nazca plate. Mem Geol Soc Am 154:199–208

  6. Davidson JP, Dungan MA, Ferguson KM, Colucci MT (1987) The San Pedro-Pellado volcanic complex, southern Chilean Andes. Geology 15:443–446

  7. Davidson JP, Ferguson KM, Colucci MT, Dungan MA (1988) The origin and evolution of magmas from the San Pedro-Pellado Volcanic Complex. Contrib Mineral Petrol 100:429–445

  8. DePaolo DJ (1981) Trace element and isotopic effects of combined wallrock assimilation and fractional crystallization. Earth Planet. Sci Lett 53:189–202

  9. Deruelle B, Harmon RS, Moorbath S (1983) Combined Sr-O isotope relationships and petrogenesis of Andean volcanics of South America. Nature 302:814–816

  10. Evensen NM, Hamilton PJ, O'Nions RK (1978) Rare earth abundances in chondritic meteorites. Geochim Cosmochim Acta 42:1199–1212

  11. Francis PW, Thorpe RS, Moorbath S, Kretschmar GA, Hammill M (1980) Strontium isotope evidence for crustal contamination of calc-alkaline volcanic rocks from Cerro Galan, northwest Argentina. Earth Planet Sci Lett 48:257–267.

  12. Frey FA, Gerlach DC, Hickey RL, Lopez-Escobar L, Munizaga-Villavicencio F (1984) Petrogenesis of the Laguna del Maule volcanic complex, Chile (36° S). Contrib Mineral Petrol 88:133–149

  13. Futa K, Stern CR (1988) Sr and Nd isotopic and trace element compositions of recent volcanic centers of the Southern Andes: implications for petrogenesis of orogenic magmas along a continental margin. Earth Planet Sci Lett 88:253–262

  14. Gerlach DC (1985) Geochemistry and petrology of recent volcanics of the Puyehue-Cordon Caulle Area, Chile (40.5° S). Ph.D. Thesis, Massachusetts Institute of Technology, Cambridge, MA

  15. Gerlach DC, Frey FA, Moreno-Roa H, Lopez-Escobar L (1988) Recent volcanism in the Puyehue-Cordon Caulle region, Southern Andes, Chile (40.5° S): Petrogenesis of evolved lavas. J Petrol 29:333–382

  16. Gill, JB (1981) Orogenic andesites and plate tectonics. Springer, New York Berlin Heidelberg, 390 pp

  17. Grove TL, Baker MB (1984) Phase equilibrium controls on the tholeiitic versus calc-alkaline differentiation trends. J Geophys Res 89:3235–3274

  18. Grove TL, Donelly-Nolan JM (1986) The evolution of young silicic lavas at Medicine Lake volcano, California: Implications for the origin of compositional gaps in calc-alkaline series lavas, Contrib Mineral Petrol 92:281–302

  19. Grove TL, Gerlach DC, Sando TW (1982) Origin of calc-alkaline series lavas at Medicine Lake Volcano by fractionation, assimilation and mixing. Contrib Mineral Petrol 80:160–182

  20. Hanus V, Vanek J (1978) Morphology of the Andean WadatiBenioff zone, andesitic volcanism, and tectonic features of the Nazca plate. Tectonphysics 44:65–77

  21. Harmon RS, Hoefs J (1984) O-isotope relationships in Cenozoic volcanic rocks: evidence for a heterogeneous mantle source and open system magmagenesis. In: Dungan MA, Grove TL, Hildreth W (eds) Proceedings of the ISEM Conference on Open Magmatic Systems. ISEM, Dallas, pp 69–71

  22. Harmon RS, Barreiro BA, Moorbath S, Hoefs J, Francis PW, Thorpe RS, Deruelle B, McHugh J, Viglino JA (1984) Regional O-, Sr- and Pb-isotope relationships in late Cenozoic calc-alkaline lavas of the Andean Cordillera. J Geol Soc Lond 141:803–822

  23. Hart SR (1976) LIL element geochemistry, Leg 34 basalts. In: Yeats RS, Hart SR (eds) Initial reports of the deep sea drilling project, Leg 34. (US Govt Printing Office, Washington DC, pp 283–288

  24. Hart SR, Brooks C (1977) The chemistry and evolution of the early pre-Cambrian mantle. Contrib Mineral Petrol 61:109–128

  25. Hawkesworth CJ, Norry MJ, Roddick JC, Baker PE (1979) 143Nd/ 144Nd, 87Sr/86Sr and incompatible element variations in calcalkaline andesites and plateau lavas from South America. Earth Planet Sci Lett 42:45–57

  26. Hawkesworth CJ, Hammill M, Gledhill AR, Van Calsteren P, Rogers G (1982) Isotope and trace element evidence for late stage intra-crustal melting in the high Andes. Earth Planet Sci Lett 58:240–254

  27. Hickey RL, Gerlach DC, Frey FA (1984) Geochemical variations in volcanic rocks from Central-south Chile (33°–42° S): Implications for their petrogenesis. In: Harmon RS, Barreiro B (eds) Andean magmatism: chemical and isotopic constraints. Shiva, Cheshire, England, pp 72–95

  28. Hickey RL, Frey FA, Gerlach DC, Lopez-Escobar L (1986) Multiple sources for basaltic arc rocks from the southern volcanic zone of the Andes (34°–41° S): trace element and isotopic evidence for contributions from subducted oceanic crust, mantle and continental crust. J Geophys Res 91:5963–5983

  29. Hildreth W, Moorbath S (1988) Continental influence on arc magmatism in central Chile. Contrib Mineral Petrol 98:455–489

  30. Hole MJ, Saunders AD, Marriner GF, Tarney J (1984) Subduction of pelagic sediments: implications for the origin of Ce-anomalous basalts from the Mariana Islands. J Geol Soc Lond 141:453–472

  31. Ila P, Frey FA (1984) Utilization of neutron activation analysis in the study of geologic materials. Atomkernenergie Kerntechnik 44:710–716

  32. James DE (1982) A combined O, Sr, Nd and Pb isotopic and trace element study of crustal contamination in central Andean lavas, I. Local geochemical variations. Earth Planet Sci Lett 57:47–62

  33. Kay SM, Rapela CW (1986) Mixing of arc and continental alkaline sources in the Southern Andes: Geochemistry of Lower MidTertiary Andean volcanic rocks (40–42° S). EOS, Trans Am Geophys Union 67:1281

  34. Lomnitz C (1962) On Andean structure. J Geophys Res 76:351–363

  35. Lopez-Escobar L, Frey FA (1976) Rocas volcanics cuaternarias de Chile central-sur (33°–41° S): modelos petrogeneticos sugeridos por las tierras raras. Actas primer Congreso Geologico Chilene, F223–F246, Agosto 1976, Santiago, Chile

  36. Lopez-Escobar L, Moreno-Roa H (1981) Erupción de 1979 del Volcan Mirador, Andes del Sur, 40° 21′ S: caracteristicas geoquimicas de las lavas y xenolitos graniticos. Rev Geol Chile 13:17–33

  37. Lopez-Escobar L, Frey FA, Vergara M (1977) Andesites and high alumina basalts from the central-south Chile High Andes: Geochemical evidence bearing on their petrogenesis. Contrib Mineral Petrol 63:199–228

  38. Lopez-Escobar L, Moreno-Roa H, Lahsen-Azar A, Munizaga-Villavicencio F (1984) Evolutión geologica y geoquimica del Volcan Villarrica, analisis de los recursos no-renovables y del riesgo geologico del area. Departamento de Geologica y Geofisica, Universidad de Chile-FONDECYT

  39. Lowrie A, Hey R (1981) Geological and geophysical variations along the western margin of Chile near Lat. 33° to 36° S and their reaction to Nazca plate subduction. Geol Soc Am Mem 154:741–754

  40. Luhr JF, Carmichael ISE (1980) The Colima volcanic complex, Mexico, I. Post-caldera andesites from Volcan. Colima Contrib Mineral Petrol 71:343–372

  41. McMillan NJ, Moorbath S, Harmon RS, Lopez-Escobar L (1986) Volcan Mocho-Choshuenco: a case study of andesite petrogenesis in the Southern Volcanic Zone, Chile. Geol Soc Am Abstr Progr 18:691

  42. Morris JD, Hart SR (1983) Isotopic and incompatible element constraints on the genesis of island arc volcanics, Cold Bay and Amak Island, Aleutians. Geochim Cosmochim Acta 47:2015–2030

  43. Morris JD, Harmon RS, Tera F, Lopez-Escobar L, Klein J, Middleton R (1980) 10Be and Pb-isotope evidence for sediment subduction in the southern Andes. In: Proceedings of the Intl. Symposium on Magmatic Evolution of the Andes (in press)

  44. Munoz J, Stern CR (1988) The Quaternary volcanic belt of the southern continental margin of South America: Transverse structural and petrochemical variations across the segment between 38° and 39° S. J S Am Earth Sci 1: 147–161

  45. Munoz J, Stern CR (1989) Alkaline magmatism within the segments 38°–39° S of the Plio-Quaternary volcanic belt of the southern South American continental margin. J Geophys Res 94:4545–4560

  46. Nicholls IA, Ringwood AE (1973) Effect of water on olivine stability in tholeiites and the production of silica-saturated magmas in the island arc environment. J Geol 81:285–300

  47. Rhodes JM (1983) Homogeneity of lava flows: chemical data for historic Mauna Loan eruptions. J Geophys Res (Supplement) 88:A869-A879

  48. Rhodes JM, Blanchard DP, Rogers KV, Jacobs JW, Brannon JC (1976) Petrology and chemistry of basalts from the Nazca plate: Part 2 — major and trace element chemistry. In: Yeats RS, Hart SR (eds) Initial reports of the deep sea drilling project, Leg 34. US Gov Printing Office, Washington, D.C., pp 239–244

  49. Stauder W (1973) Mechanism and spatial distribution of Chilean earthquakes with relation to subduction of oceanic plates. J Geophys Res 78:5033–5061

  50. Staudigel H, Frey FA, Hart SR (1980) Incompatible trace element geochemistry and 87Sr/86Sr in basalts and corresponding glasses and palagonites. In: Donnelly T, Francheteau J (eds) Initial Repts. DSDP Leg 53, US Gov Printing Office, Washington, D.C., pp 1137–1144

  51. Stern CR, Futa K, Zicheng P (1983) Pb, Sr and Nd isotopic composition of alkali basalts of the Patagonian plateau lavas, South America. Geol Soc Am Abstr Prog 15:696–697

  52. Stern CR, Futa K, Muehlenbachs K, Dobbs FM, Munoz J, Godoy E, Charrier R (1984) Sr, Nd, Pb and O isotopic composition of Late Cenozoic volcanics, northernmost SVZ (33°–34° S). In: Andean magmatism: chemical and isotopic constraints Harmon RS, Barreiro BA (eds). Shiva, Cheshire, England, pp 96–105

  53. Stern CR, Futa K, Saul S, Skewes MA (1986) Nature and evolution of the subcontinental mantle lithosphere below southern South America and implications for Andean magma genesis. Rev Geol Chile 27:41–53

  54. Stern CR, Frey FA, Futa K, Zartman RE, Peng ZC, Kyser TK (1989) Trace element and Sr, Nd, Pb and O isotopic compositions of mantle xenolith bearing and other Pliocene and Quaternary alkali basalts of the Patagonian plateau lavas of southernmost South America. Contrib Mineral Petrol

  55. Stern RJ, Ito E (1983) Trace element and isotopic constraints on the source of magmas in the active volcano and Mariana Island arcs, western Pacific. J Volcanol Geotherm Res 18:461–482

  56. Taylor SR, McLennan SM (1981) The composition and evolution of the continental crust: rare earth evidence from sedimentary rocks. Phil Trans R Soc Lond A301:381–399

  57. Thompson G, Bryan WB, Frey FA, Dickes JS, Suen CJ (1976) Petrology and geochemistry of basalts from DSDP Leg 34, Nazca plate. In: Yeats RS, Hart SR (s) Initial Reports of the Deep Sea Drilling Project, Leg 34. US Gov Printing Office, Washington, D.C., pp 215–226

  58. Thorpe RS, Francis PW (1979) Variations in Andean andesite compositions and their petrogenetic significance. Tectonphysics 57:53–70

  59. Unruh DM, Tatsumoto M (1976) Lead isotopic composition and uranium, thorium and lead concentrations in sediments and basalts from the Nazca plate. In: Yeats RS, Hart SR (eds) Initial reports of the deep sea drilling project, Leg 34. US Government Printing Office, Washington, D.C., pp 341–347

  60. Volfinger M (1976) Effect de la temperature sur les distributions de Na, Rb et Cs entre la sanidine, la muscovite, la phlogopite et une solution hydrothermale sous une pression de 1 kbar. Geochim Cosmochim Acta 40:267–282

  61. Watson EB, Green TH (1981) Apatite/liquid partition coefficients for the rare earth elements and strontium, Earth Planet Sci Lett 56:405–421

  62. Wood DA (1979) A variably veined suboceanic upper mantlegenetic significance for mid-ocean ridge basalts from geochemical evidence. Geology 7:499–503

  63. Wyllie PJ, Sekine T (1982) The formation of mantle phlogopite in subduction zone hybridization. Contrib Mineral Petrol 79:375–380

  64. Zindler, A, Hart, SR, Frey, FA, Jakobsson, SP (1979) Nd and Sr isotope ratios and rare earth element abundances in Rekyanes Peninsula basalts. Earth Planet Sci Lett 45:249–262

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Correspondence to Rosemary Hickey -Vargas.

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Hickey -Vargas, R., Roa, H.M., Escobar, L.L. et al. Geochemical variations in Andean basaltic and silicic lavas from the Villarrica-Lanin volcanic chain (39.5° S): an evaluation of source heterogeneity, fractional crystallization and crustal assimilation. Contr. Mineral. and Petrol. 103, 361–386 (1989). https://doi.org/10.1007/BF00402922

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Keywords

  • Fractional Crystallization
  • 86Sr
  • Crustal Contamination
  • Scoria Cone
  • Lanin