Abstract
The Ministers Island dike in southwest New Brunswick is a quartz tholeiitic member of the Late Triassic to Early Jurassic dike suite that outcrops along the east coast of North America. The dike's phenocryst assemblage is orthopyroxene + augite + plagioclase. The combination of petrographic, chemical (both phase and whole rock), isotopic and experimental work on representative samples from the dike places important constraints on the petrogenesis of the Ministers Island dike and by analogy on the other members of the dike suite. The petrographic, analytical and experimental results show that the Ministers Island dike magma underwent high pressure (0.8 to 1.0 GPa) fractionation of augite, followed by augite + orthopyroxene, and finally augite + plagioclase. The absence of olivine as either a phenocryst or an experimentally observed high pressure liquidus phase indicates that the magma evolved away from the Ol-Cpx-Opx-Plag pseudo-invariant point while still at high pressure and there was sufficient time for any olivine to settle out of the magma prior to emplacement of the dike. The Sr and Nd isotopic results support a metasomatised mantle source similar to EMI but with slightly more radiogenic Nd.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Anders E, Ebihara M (1982) Solar-system abundances of elements. Geochim Cosmochim Acta 46:2363–2380
Andersen DJ, Lindsley DH (1988) Internally consistent solution models for Fe−Mg−Mn−Ti oxides: Fe−Ti oxides. Am Mineral 73:714–726
Burke KBS, Hamilton JB, Gupta VK (1973) The Caraquet dike: its tectonic significance. Can J Earth Sci 10:1760–1768
DePaolo DJ (1981) Trace element and isotopic effects of combined wallrock assimilation and fractional crystallization. Earth Planet Sci Lett 53:189–202
Dostal J, Dupuy C (1984) Geochemistry of the North Mountain basalts (Nova Scotia, Canada). Chem Geol 45:245–261
Dunn T (1987) Partitioning of Lu, Hf, Ti, and Mn between clinopyroxene, olivine and basaltic melt at high pressure. Contrib Mineral Petrol 98:476–484
Dunn T (1990) An automated oxygen fugacity control system for 0.1 MPa high-temperature furnaces. Am Mineral 75:398–400
Elthon D, Scarfe CM (1984) High-pressure phase equilibria of a high-magnesia basalt and the genesis of primary oceanic basalts. Am Mineral 69:1–15
Hart SR (1988) Heterogeneous mantle domains: signatures, genesis and mixing chronologies. Earth Planet Sci Lett 90:273–296
Hodych JP, Hayatsu A (1988) Paleomagnetism and K−Ar isochron dates of Early Jurassic basaltic flows and dikes of Atlantic Canada. Can J Earth Sci 25:1972–1989
Hofmann AW (1988) Chemical differentiation of the earth: the relationship between mantle, continental crust, and oceanic crust. Earth Planet Sci Lett 90:297–314
Irving AJ, Frey FA (1984) Trace element abundances in megacrysts and their host basalts: constraints on partition coefficients and megacryst genesis. Geochim Cosmochim Acta 48:1201–1221
Jacobsen SR (1988) Isotopic constraints on mantle-crust evolution. Geochim Cosmochim Acta 52:1341–1350
Jones LM, Mossman DJ (1988) The isotopic composition of strontium of the Early Jurassic North Mountain Basalts, Nova Scotia. Can J Earth Sci 25:942–944
Kilinc A, Carmichael ISE, Rivers ML, Sack RO (1983) The ferricferrous ratio of natural silicate liquids equilibrated in air. Contrib Mineral Petrol 83:136–141
Lajtai EZ, Stringer P (1981) Joints, tensile strength and preferred fracture orientation in sandstones, New Brunswick and Prince Edward Island, Canada. Marit Sediments Atlantic Geol 17:70–87
Lawrence DE (1966) A contribution to the petrology of the Great Dike of Nova Scotia. M Sc thesis, Dalhousie University, Halifax, NS
Lindsley DH (1983) Pyroxene thermometry. Am Mineral 68:477–493
Manspeizer W, Puffer JH, Cousminer HL (1978) Separation of Morocco and eastern North America: A Triassic-Liassic stratigraphic record. Geol Soc Am Bull 89:901–920
McIlwaine WH (1968) Age and origin of the Perry Formation (Devonian), Charlotte County, New Brunswick, M Sc thesis, University of New Brunswick, Fredericton, NB
Menzies MA, Hawkesworth CJ eds (1987) Mantle Metasomatism. Academic Press, London
Papezik VS, Barr SM (1981) The Shelburne dike, an early Mesozoic diabase dike in Nova Scotia: mineralogy, chemistry, and regional significance. Can J Earth Sci 18:1346–1355
Papezik VS, Hodych JP, Goodacre AK (1975) The Avalon magnetic lineament — a possible continuation of the Triassic dike system of New Brunswick and Nova Scotia. Can J Earth Sci 12:332–335
Papezik VS, Greenough JD, Colwell JA, Mallinson TJ (1988) North Mountain basalt from Digby, Nova Scotia: models for a fissure eruption from stratigraphy and petrochemistry. Can J Earth Sci 25:74–83
Pe-Piper G, Jansa LF (1986) Triassic olivine-normative diabase from Northumberland Strait, eastern Canada: implications for continental rifting. Can J Earth Sci 23:1013–1021
Pe-Piper G, Loncarevic BD (1989) Offshore continuation of Meguma Terrane, southwestern Nova Scotia. Can J Earth Sci 26:176–191
Philpotts AR, Martello A (1986) Diabase feeder dikes for the Mesozoic basalts in southern New England. Am J Sci 286:105–126
Stormer JC (1983) The effects of recalculation on estimates of temperature and oxygen fugacity from analyses of multicomponent iron-titanium oxides. Am Mineral 68:586–594
Stringer P, Burke KBS (1985) Structure in southwest New Brunswick. Excursion 9. In: Pickerill RK, Mawer CK, Fyffe LR (eds) Field Excursions, Vol III. Geol Assoc Can/Mineral Assoc Can: 1–34
Tatsumi Y, Hamilton DL, Nesbitt RW (1986) Chemical characteristics of fluid phase released from a subducted lithosphere and origin of arc magmas: evidence from high-pressure experiments and natural rocks. J Volcanol Geotherm Res 29:293–309
Ulmer P (1989) The dependence of Fe2+−Mg cation-partitioning between olivine and basaltic liquid on pressure, temperature and composition: An experimental study to 30 kbars. Contrib Mineral Petrol 101:261–273
Weigand PW, Ragland PC (1970) Geochemistry of Mesozoic dolerite dikes from eastern North America. Contrib Mineral Petrol 29:195–214
Weill DF, McKay GA (1976) The partitioning of Mg, Fe, Sr, Ce, Sm, Eu and Yb in lunar igneous systems and a possible origin of KREEP by equilibrium partial melting. Proc Lunar Sci Conf 6th:1143–1158
Wilson M (1989) Igneous petrogenesis. Unwin Hyman, London
Zindler A, Hart SR (1986) Chemical geodynamics. Ann Rev Earth Planet Sci 14:493–571
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Dunn, T., Stringer, P. Petrology and petrogenesis of the Ministers Island dike, southwest New Brunswick, Canada. Contr. Mineral. and Petrol. 105, 55–65 (1990). https://doi.org/10.1007/BF00320966
Issue Date:
DOI: https://doi.org/10.1007/BF00320966