Abstract
The stratigraphy and geochemistry of the uppermost 200–300 m of the metabasalt sequence of the Solund-Stavfjord Ophiolite Complex of western Norway has been investigated over a lateral distance of ~6 km. Volcanologically, this sequence was constructed in a cyclic manner. The lowest part of a volcanic cycle is characterised by sheet flows and/or large pillows followed by lavas in which pillows become progressively smaller upwards. In several of the cycles, pillow lavas are differentiated Fe–Ti basalts at the base, and successive flows become gradually more primitive stratigraphically upwards. The compositional differences between the bottom and top of a cycle can be substantial (e.g. TiO2 is 2.98–1.00 wt%, Zr 227–76 ppm, and Cr 125–520 ppm respectively). Nd isotopic and other data suggest that all the basaltic magmas were generated from a uniform source. Concomitant with the upward decrease in the Ti and Fe contents of the metabasalts through a volcanic cycle, estimated magma densities also decrease. We attribute the geochemical stratigraphy of the metabasalts to mainly reflect magma mixing in a frequently replenished magma chamber. Hybrids in the chamber repeatedly mixed with inflowing magmas which were more primitive and less dense. During the time intervals between cycles, the magma chamber was essentially closed and extensive fractional crystallisation took place. In some sequences, however, volcanic cycles and stratigraphical geochemical trends are poorly defined. We tentatively propose that in such cases the volcanics were erupted from more than one magma chamber.
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References
Bell BR (1983) Significance of ferrodioritic liquids in magma mixing processes. Nature 306:323–327
Blake S (1981) Volcanism and dynamics of open magma chambers. Nature 289:783–785
Bottinga Y, Richet P, Weill DF (1983) Calculation of density and thermal expansion coefficient of silicate liquids. Bull Mineral 106:129–138
Campbell IH (1996) Fluid dynamic processes in basaltic magma chambers. In: Cawthorn RG (ed) Layered intrusions. Elsevier, Amsterdam, pp 45–76
Campbell IH, Turner JS (1986) The influence of viscosity on fountains in magma chambers. J Petrol 27:1–30
Coish RA (1977) Ocean floor metamorphism in the Betts Cove Ophiolite, Newfoundland. Contrib Mineral Petrol 60:277–302
Cox KG, Bell JD, Pankhurst RJ (1979) The interpretation of igneous rocks. Chapman & Hall, London
Crisp JA (1984) Rates of magma emplacement and volcanic output. J Volcanol Geotherm Res 20:177–211
Detrick RS, Buhl P, Vera E, Mutter J, Orcutt J, Madsen J, Brocher T (1987) Multichannel seismic imaging of a crustal magma chamber along the East Pacific Rise. Nature 326:35–41
Dick HJB, Meyer PS, Bloomer S, Kirby S, Stakes D, Mawer C (1991) Lithostratigraphic evolution of an in situ section of oceanic layer 3. In: von Herzen RP, Robinson PT et al. (eds) Proceedings of the Ocean Drilling Program, Scientific Results 118. College Station, Texas, Ocean Drilling Program, pp 439–538
Dilek Y, Furnes H, Skjerlie KP (1997) Propagating rift tectonics of a Caledonian marginal basin: multi-stage seafloor spreading history of the Solund-Stavfjord ophiolite in western Norway. Tectonophysics 280:213–238
Dilek Y, Moores EM, Furnes H (1998) Structure of modern oceanic crust and ophiolites and implications for faulting and magmatism of oceanic spreading centers. In: Buck R, Karson J, Delaney P, Lagabrielle Y (eds) Faulting and magmatism at mid-ocean ridges. Am Geophys Union, Geophys Monogr 106:219–265
Fujii T, Scarfe CM (1985) Composition of liquids coexisting with spinel lherzolite at 10 kbar and the genesis of MORBs. Contrib Mineral Petrol 90:18–28
Furnes H, Skjerlie KP, Pedersen RB, Andersen TB, Stillman CJ, Suthren RJ, Tysseland M, Garmann LB (1990) The Solund-Stavfjord Ophiolite Complex and associated rocks, West Norwegian Caledonides: geology, geochemistry and tectonic environment. Geol Mag 127:209–224
Furnes H, Dilek Y, Skjerlie KP, Ryttvad HL, Fonneland HC (1998) Variations in basaltic geochemistry along a propagating rift of the Late Ordovician marginal basin of the West Norwegian Caledonides. Terra Nova 10:21–26
Furnes H, Skjerlie KP, Dilek Y (2000) Petrology, tectonics, and hydrothermal alteration of a fossil backarc oceanic crust: Solund-Stavfjord Ophiolite Complex of western Norwegian Caledonides—a review. In: Dilek Y, Moores EM, Nicolas A (eds) Ophiolites and ocean crust: new insight from field studies and Ocean Drilling Program. Geol Soc Am Spec Pap 349:443–460
Furnes H, Hellevang B, Dilek Y (2001) Cyclic volcanic stratigraphy in a Late Ordovician marginal basin, west Norwegian Caledonides. Bull Volcanol 63:164–178
Govindaraju K (1994) 1994 compilation of working values and sample description for 383 geostandards. Geostand Newslett Spec Issue 18
Grove TL, Kinzler RJ, Bryan WB (1992) Fractionation of Mid-Ocean Ridge Basalt (MORB). In: Morgan JP, Blackman DK, Sinton JM (eds) Mantle flow and melt generation at mid-ocean ridges. Am Geophys Union, Geophys Monogr 71:281–310
Gudmundsson A (1990) Emplacement of dikes, sills and crustal magma chambers at divergent plate boundaries. Tectonophysics 176:257–275
Gudmundsson A (1995) Geometry and growth of dykes. In: Baer G, Heimann A (eds) Physics and chemistry of dykes. Balkema, Rotterdam, pp 23–34
Gudmundsson A (1998) Magma chambers modeled as cavities explain the formation of rift zone central volcanoes and their eruption and intrusion statistics. J Geophys Res 103:7401–7412
Gudmundsson A (2000) Dynamics of volcanic systems in Iceland: example of tectonism and volcanism at juxtaposed hot spot and mid-ocean ridge systems. Annu Rev Earth Planet Sci 28:107–140
Gudmundsson A (2002) Emplacement and arrest of sheets and dykes in central volcanoes. J Volcanol Geotherm Res 116:279–298
Harding AJ, Kent GM, Orcutt JA (1993) A multichannel seismic investigation of upper crustal structure at 9°N and on the East Pacific Rise: implication for crustal accretion. J Geophys Res 98:13925–13944
Hellevang H (2002) Volcanic and petrological evolution of Late Ordovician oceanic crust: the Stavenes segment of the Solund-Stavfjord ophiolite. Cand Sci Thesis, University of Bergen, Norway
Hildreth W (1981) Gradients in silicic magma chambers: implications for lithospheric magmatism. J Geophys Res 86:10153–10292
Huppert HE, Sparks RSJ, Whitehead JA, Hallworth J (1986) Replenishment of magma chambers with light inputs. J Geophys Res 91:6113–6122
Keszthelyi L, Self S (1998) Some physical requirements for the emplacement of long basaltic lava flows. J Geophys Res 103:27303–27324
Lange RA, Carmichael ISE (1987) Densities of Na2O–K2O–CaO–MgO–FeO–Fe2O3–Al2O3–TiO2–SiO2 liquidus: new measurements and derived partial molar properties. Geochim Cosmochim Acta 51:2931–2946
Langmuir CH, Klein EM, Plank T (1992) Petrological systematics of mid-ocean ridge basalts: constraints on melt generation beneath ocean ridges. In: Morgan JP, Blackman DK, Sinton JM (eds) Mantle flow and melt generation at mid-ocean ridges. Geophys Monogr 71:183–280
Machado F (1974) The search for magmatic reservoirs. In: Civetta L, Gasparini P, Luongo G, Rapolla A (eds) Physical volcanology. Elsevier, Amsterdam, pp 255–273
Malpas J (1990) Crustal accretionay processes in the Troodos ophiolite, Cyprus: evidence from field mapping and deep crustal drilling. In: Gibson I, Malpas J, Robinson PT, Xenophontos C (eds) Ophiolites, oceanic crustal analogues. Geol Surv Dept, Nicosia, Cyprus, pp 65–74
Melson WG, Vallier TL, Wright TL, Byerly G, Nelson J (1976) Chemical diversity of abyssal volcanic glass erupted along the Pacific, Atlantic, and Indian Ocean seafloor spreading centers. In: Sutton G, Manghari MH, Moberly R (eds) The geophysics of the Pacific Ocean Basin and its margins. Geophys Monogr 12:351–367
Nelson BK, DePaolo DJ (1985) Rapid production of continental crust 1.7 to 1.9 b.a. ago: Nd isotopic evidence from the basement of the North American mid-continent. Geol Soc Am Bull 96:746–754
O'Hara MJ, Mathews RE (1981) Geochemical evolution in an advancing, periodically replenished, periodically tapped, continuously fractionated magma chamber. J Geol Soc Lond 138:237–277
Padfield T, Gray A (1971) Major element rock analyses by X-ray fluorescence—a simple fusion method. NV Philips, Eindhoven, Analytical Equipment FS 35
Pallister JS, Hopson CA (1981) Semail ophiolite plutonic suite: field relations, phase variations and layering, and a model of a spreading ridge magma chamber. J Geophys Res 86:2593–2644
Pearce JA, Norry MJ (1979) Petrogenetic implications of Ti, Zr, Y and Nb variations in volcanic rocks. Contrib Mineral Petrol 69:33–47
Pedersen RB (1986) The nature and significance of magma chamber margins in ophiolites: examples from the Norwegian Caledonides. Earth Planet Sci Lett 77:100–112
Pin C, Briot D, Bassin C, Poitrasson F (1994) Concomitant separation of strontium and samarium-neodynium for isotope analyses in silicate samples, based on specific extraction chromatography. Anal Chim Acta 298:209–217
Richard P, Shimizu N, Allégre CJ (1976) 143Nd/146Nd, a natural tracer: an application to oceanic basalts. Earth Planet Sci Lett 31:269–278
Robinson PT, Flower MFJ, Swanson DA, Staudigel H (1979) Lithology and eruptive stratigraphy of Cretaceous oceanic crust, Western Atlantic Ocean. In: Donelly T, Francheteau J, Bryan W, Robinson PT, Flower M, Salisbury M et al. (eds) Initial Reports DSDP LI, LII, LIII. US Government Printing Office, Washington, DC, pp 1535–1555
Ryttvad HL, Furnes H, Skjerlie KP, Rolfsen R (2000) Geochemistry and petrogenesis of extrusive rocks, dykes and high-level plutonic rocks on the island of Oldra, Solund-Stavfjord Ophiolite Complex, western Norway. Norsk Geol Tidsskr 80:97–119
Saemundsson K (1991) The geology of the Krafla volcanic system. In: Gardarsson A, Einarsson A (eds) Myvatn's nature (in Icelandic). Hid Isslenska Natturufraedifelag, Reykjavik, pp 24–95
Schilling JG, Zajac M, Evans R, Johnston T, White W, Devine JD, Kingsley R (1983) Petrological and geochemical variations along the Mid-Atlantic Ridge from 29°N to 73°N. Am J Sci 283:510–586
Sinton JM, Detrick RS (1992) Mid-ocean ridge magma chambers. J Geophys Res 97:197–216
Sinton JM, Wilson DS, Christie DM, Hey RN, Delaney JR (1983) Petrologic consequences of rift propagation on oceanic spreading ridges. Earth Planet Sci Lett 62:193–207
Skjerlie KP, Furnes H (1990) Evidence for a fossil transform fault in the Solund-Stavfjord Ophiolite Complex: West Norwegian Caledonides. Tectonics 9:1631–1648
Skjerlie KP, Furnes H, Johansen RJ (1989) Magmatic development and tectonomagmatic models for the Solund-Stavfjord Ophiolite Complex, West Norwegian Caledonides. Lithos 23:137–151
Slater L, McKenzie D, Grønvold K, Shimizu N (2001) Melt generation and movement beneath Theistareykir, NE Iceland. J Petrol 42:321–354
Smith DK, Cann JR (1993) Building the crust at the Mid-Atlantic Ridge. Nature 365:707–715
Sparks RSJ, Huppert HE (1984) Density changes during the fractional crystallization of basaltic magmas: fluid dynamic implications. Contrib Mineral Petrol 85:300–309
Sparks RSJ, Meyer P, Sigurdsson H (1980) Density variation amongst mid-ocean ridge basalts: implications for magma mixing and the scarcity of primitive lavas. Earth Planet Sci Lett 46:419–430
Staudigel H, Hart SR (1983) Alteration of basaltic glass: mechanism and significance for the oceanic crust-seawater budget. Geochim Cosmochim Acta 47:37–50
Stolper E (1980) A phase diagram for mid-ocean ridge basalts: preliminary results and implications for petrogenesis. Contrib Mineral Petrol 74:13–27
Stopler E, Walker D (1980) Melt density and the average composition of basalts. Contrib Mineral Petrol 74:7–12
Toomey DR, Purdy GM, Solomon SC, Wilcock WSD (1990) The three-dimensional seismic velocity structure of the East pacific rise near latitude 9°30′N. Nature 347:639–645
Walker GPL (1973) Lengths of lava flows. Philos Trans R Soc Lond A 274:107–118
Wilson DS, Clague DA, Sleep NH, Morton JL (1988) Implications of magma convection for the size and temperature of magma chambers at fast spreading ridges. J Geophys Res 93:11974–11984
Acknowledgements
This study was carried out with financial support from the Norwegian Research Council and Meltzers Høyskolefond. We further thank Shan de Silva (University of North Dakota) and one anonymous reviewer for their constructive comments and suggestions on an early version of the manuscript.
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Furnes, H., Hellevang, B., Robins, B. et al. Geochemical stratigraphy of the lavas of the Solund-Stavfjord Ophiolite Complex, W. Norway, and magma-chamber dynamics. Bull Volcanol 65, 441–457 (2003). https://doi.org/10.1007/s00445-002-0271-9
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DOI: https://doi.org/10.1007/s00445-002-0271-9