Hostname: page-component-7c8c6479df-5xszh Total loading time: 0 Render date: 2024-03-28T11:56:12.528Z Has data issue: false hasContentIssue false

Oligocene lamproite containing an Al-poor, Ti-rich biotite, Middle Park, northwest Colorado, USA

Published online by Cambridge University Press:  05 July 2018

R. N. Thompson
Affiliation:
Department of Geological Sciences, University of Durham, South Road, Durham DH1 3LE, UK
D. Velde
Affiliation:
Départment de Petrologie, Université P. et M. Curie (U.R.A. 736 du CNRS), 4, Place Jussieu, 75252 Paris, France
P. T. Leat
Affiliation:
British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK
M. A. Morrison
Affiliation:
School of Earth Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
J. G. Mitchell
Affiliation:
Department of Physics, The University, Newcastle upon Tyne, NEI 7RU, UK
A. P. Dickin
Affiliation:
Department of Geology, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4M1
S. A. Gibson
Affiliation:
Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK

Abstract

A small 33 ± 0.8 Ma lamproite pluton is exposed in the midst of a 23–26 Ma basalt-rhyolite province in Middle Park, NW Colorado. It contains abundant phlogopite phenocrysts in a fine-grained groundmass of analcime pseudomorphs after leucite, biotite, potassic richterite, apatite, ilmenite and accessory diopside. The phlogopite phenocryst cores contain ∼4 wt.% TiO2, 1% Cr2O3 and 0.2% BaO. The smallest groundmass biotites have normal pleochroism but compositions unlike any previously reported, with ∼2% Al2O3, ∼8% TiO2 and F <1.5%. Apart from those elements affected by leucite alteration, both the elemental and isotopic composition of this lamproite are close to those of the Leucite Hills, Wyoming. Its Nd-isotopic model age (TDM = 1.6 Ga) is outside the Leucite Hills range but within that of other Tertiary strongly potassic magmatism in the region underlain by the Wyoming craton. Evidence from both teleseismic tomography and the mantle xenoliths within other western USA mafic ultrapotassic igneous suites shows that the total lithospheric thickness beneath NW Colorado was probably ∼150–200 km at 33 Ma, when the Middle Park lamproite was emplaced. This is an important constraint on tectonomagmatic models for the Cenozoic evolution of this northernmost part of the Rio Grande rift system.

Type
Petrology
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1997

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Alibert, C., Michard, A. and Albarede. F. (1986) Isotope and trace element geochemistry of the Colorado Plateau volcanics. Geochim. Cosmochim. Acta, 50, 2735-76.CrossRefGoogle Scholar
Best, M.G. and Christiansen, E.H. (1991) Limited extension during peak Tertiary volcanism, Great Basin of Nevada and Utah. J. Geophys. Res., 96, 13509-28.CrossRefGoogle Scholar
Bol, L.C.G.M., Bos, A., Sauter, P.C.C. and Jansen, J.B.H. (1989) Barium-titanium-rich phlogopites in marbles from Rogaland, southwest Norway. Amer. Mineral., 74, 439-47.Google Scholar
Carlson, R.W. and Irving, A.J. (1994) Depletion and enrichment history of subcontinental lithospheric mantle: an Os, Sr, Nd and Pb isotopic study of ultramafic xenoliths from the northwestern Wyoming Craton. Earth Planet. Sci. Lett., 126, 457-72.CrossRefGoogle Scholar
Carlson, R.W., Esperanqa, S. and Svisero, D.P., (1996) Chemical and Os isotopic study of Cretaceous potassic rocks from southern Brazil. Contrib. Mineral. Petrol., submitted.CrossRefGoogle Scholar
Carmichael, I.S.E. (1967) The mineralogy and petrology of volcanic rocks from the Leucite Hills, Wyoming. Contrib. Mineral. Petrol., 15, 24-66.CrossRefGoogle Scholar
Davis, J.M. and Hawkesworth, CJ. (1995) Geochemical and tectonic transitions in the evolution of the Mogollon-Datil Volcanic Field, New Mexico, U.S.A. Chem. Geol., 119, 31-53.CrossRefGoogle Scholar
Davis, P.M., Slack, P., Dalheim, H.A., Green, W.V., Meyer, R.P., Achauer, U., Glahn, A. and Granet, M. (1993) Teleseismic tomography of continental rift zones. In Seismic Tomography: Theory and Practice (Iyer, H.M. and Hirahara, K., eds.), Chapman and Hall, 397439.Google Scholar
Della Ventura, G., Robert, J.L. and Bény, J.M. (1991) Tetrahedrally coordinated Ti4+ in synthetic Ti-rich potassic richterite: evidence from XRD, FTIR and Raman studies. Amer. Mineral, 76, 1134—40.Google Scholar
Dymek, R.F. (1983) Titanium, aluminium and interlayer cation substitutions in biotite from high-grade gneisses, West Greenland. Amer. Mineral., 68, 880-99.Google Scholar
Eaton, G.P. (1986) A tectonic redefinition of the Southern Rocky Mountains. Tectonophysics, 132, 163-93.CrossRefGoogle Scholar
Eggler, D.H., Meen, J.K., Welt, F., Dudas, F.O., Furlong, K.P., McCallum, M.E. and Carlson, R.W. (1988) Tectonomagmatism of the Wyoming Province. Colo. Sch. Mines Quart., 83, 25-40.Google Scholar
Farmer, G.L. and Boettcher, A.L. (1981) Petrologic and crystal-chemical significance of some deep-seated phlogopites. Amer. Mineral., 66, 1154-63.Google Scholar
Ferriz, F.J., Fernandez Soler, J.M. and Camara, F. (1994) Presencia de afloramientos de lamproitas en las proximidades de Moratalla y Cehegin (Murcia). Bol. Soc. Espan. Mineral. 17, 231-9.Google Scholar
Fitton, J.G., James, D. and Leeman, W.P. (1991) Basic magmatism associated with late Cenozoic extension in the western United States; compositional variations in space and time. J. Geophys. Res., 96, 13693-711.CrossRefGoogle Scholar
Foley, S.F. (1992) Vein-plus-wall-rock melting mechanisms in the lithosphere and the origin of potassic alkaline magmas. Lithos, 28, 435—53.CrossRefGoogle Scholar
Foley, S.F., Venturelli, G., Green, D.H. and Toscani, L. (1987) The ultrapotassic rocks: characteristics, classification and constraints for petrogenetic models. Earth-Sci. Rev., 24, 81-134.CrossRefGoogle Scholar
Frey, F.A. and Green, D.H. (1974) The mineralogy, geochemistry and origin of lherzolite inclusions in Victorian basanites. Geochim. Cosmochim. Acta, 38, 1023-59.CrossRefGoogle Scholar
Gans, P.B., Mahood, G.A. and Schermer, E. (1989) Synextensional magmatism in the Basin and Range Province; a case study from the eastern Great Basin. Geol. Soc. Amer. Spec. Paper, 233, 1—53.Google Scholar
Gibson, S.A., Thompson, R.N., Leat, P.T., Dickin, A.P., Morrison, M.A., Hendry, G.L. and Mitchell, J.G. (1992) Asthenosphere-derived magmatism in the Rio Grande rift, western USA: implications for con tinental break-up. In Magmatism and the Causes of Continental Break-up (Storey, B.C., Alabaster, T. and Pankhurst, R.J. eds.), Geol. Soc. London Spec. Publ., 68, 6189.Google Scholar
Gibson, S.A., Thompson, R.N., Leat, P.T., Morrison, M.A., Hendry, G.L., Dickin, A.P. and Mitchell, J.G. (1993) Ultrapotassic magmas along the flanks of the Oligo-Miocene Rio Grande rift, USA: monitors of the zone of lithospheric mantle extension and thinning beneath a continental rift. J. Petrol., 34, 187228.CrossRefGoogle Scholar
Gibson, S.A., Thompson, R.N., Leonardos, O.H., Dickin, A.P. and Mitchell, J.G. (1995a) The Late Cretaceous impact of the Trindade mantle plume: evidence from large-volume, mafic, potassic mag-matism in SE Brazil. J. Petrol., 36, 189229.CrossRefGoogle Scholar
Gibson, S.A., Thompson, R.N., Dickin, A.P. and Leonardos, O.H. (1995b) High-Ti and low-Ti mafic potassic magmas: key to plume-lithosphere interactions and continental flood-basalt genesis. Earth Planet. Sci. Lett., 136, 149-65.CrossRefGoogle Scholar
Harry, D.L. and Leeman, W.P. (1995) Partial melting of melt-metasomatized subcontinental mantle and the magma source potential of the lower lithosphere. J. Geophys. Res., 100, 10255-69.CrossRefGoogle Scholar
Hawkesworth, C., Turner, S., Gallagher, K., Hunter, A., Bradshaw, T., and Rogers, N. (1995) Calc-alkaline magmatism, lithospheric thinning and extension in the Basin and Range. J. Geophys. Res., 100, 10271-86.CrossRefGoogle Scholar
Hearn, B.C., Jr., (1989) Alkaline ultramafic magmas in north-central Montana, USA: genetic connections of alnOite, kimberlite and carbonatite. In Kimberlites and Related Rocks, 1 (Jaques, A.L., Ferguson, J. and Green, D.H., eds.), Geol. Soc. Austr. Spec. Publ., 14, 109-19.Google Scholar
Houston, R.S., Duebendorfer, E.M., Karlstrom, K.E. and Premo, W.R. (1989) A review of the geology and structure of the Cheyenne belt and Proterozoic rocks of southern Wyoming. Geol. Soc. Amer. Spec. Pap., 235, 1-12.Google Scholar
Humphreys, E.D. and Dueker, K.G. (1994) Western U.S. upper mantle structure. J. Geophys. Res., 99, 9615-34.CrossRefGoogle Scholar
Izett, G.A. (1974) Geologic map of the Trail Mountain quadrangle, Grand County, Colorado. U. S. Geol. Surv. Map, GQ-1156.Google Scholar
Izett, G.A. (1975) Late Cenozoic sedimentation and deformation in northern Colorado and adjoining areas. Mem. Geol. Soc. Amer., 144, 179209.Google Scholar
Izett, G.A. and Barclay, C.S.V. (1973) Geologic map of the Kremmling quadrangle, Grand County, Colorado. U. S. Geol. Surv. Map, GQ-1115.Google Scholar
Kuehner, S.M., Edgar, A.D. and Arima, M. (1981) Petrogenesis of the ultrapotassic rocks from the Leucite Hills, Wyoming. Amer. Mineral., 66, 663-77.Google Scholar
Leat, P.T., Thompson, R.N., Morrison, M.A., Hendry, G.L. and Dickin, A.P. (1988) Silicic magmas derived by fractional crystallization from Miocene minette, Elkhead Mountains, Colorado. Mineral. Mag. 52, 577-85.CrossRefGoogle Scholar
Leat, P.T., Thompson, R.N., Morrison, M.A., Hendry, G.L. and Dickin, A.P. (1990) Geochemistry of mafic lavas in the early Rio Grande rift, Yarmony Mountain, Colorado, U.S.A. Chem. Geol., 81, 23-43.CrossRefGoogle Scholar
Leat, P.T., Thompson, R.N., Morrison, M.A., Hendry, G.L. and Dickin, A.P. (1991) Alkaline hybrid mafic magmas of the Yampa area, NW Colorado, and their relationship to the Yellowstone mantle plume and lithospheric mantle domains. Contrib. Mineral. Petrol., 107, 310-27.CrossRefGoogle Scholar
Lipman, P.W. (1980) Cenozoic volcanism in the western United States: implications for continental tectonics. In Continental Tectonics, U.S. Nat. Acad. Sci., 161-74.Google Scholar
Luhr, J.F. and Kyser, T.K. (1989) Primary igneous analcime: the Colima minettes. Amer. Mineral., 74, 216-223.Google Scholar
McKenzie, D.P. (1989) Some remarks on the movement of small melt fractions in the mantle. Earth Planet. Sci. Lett., 95, 5372.CrossRefGoogle Scholar
Mitchell, R.H. and Bergman, S.C. (1991) Petrology of Lamproites. Plenum Press, 1—447.CrossRefGoogle Scholar
Mitchell, R.H., Platt, R.G. and Downey, M. (1987) Petrology of lamproites from Smoky Butte, Montana. J. Petrol., 28, 645-77.CrossRefGoogle Scholar
Mokhtari, A, Wagner, C. and Velde, D (1985) Presence of late crystallizing ferriannite-rich annite in basic eruptive rocks from Morocco. Neues Jahrb. Mineral. Mh., 513-20.Google Scholar
Pearson, D.G., Rogers, N.W., Irving, A.J., Smith, C.B. and Hawkesworth, C.J. (1995) Source regions of kimberlites and lamproites: constraints from Re-Os isotopes. Sixth Kimb. Conf., Novosibirsk, Russia, extended abs., 430—2.Google Scholar
Sahama, T.G. (1974) Potassium-rich alkaline rocks. In The Alkaline Rocks (Sorensen, H., ed.), John Wiley, 96109.Google Scholar
Salvioli-Mariani, E. and Venturelli, G. (1996) Temperature of crystallization and evolution of the Jumilla and Cancarix lamproites (SE Spain), as suggested by melt and solid inclusions in minerals. Europ. J. MineraL, 8, 1027-39.CrossRefGoogle Scholar
Snyder, G.L. (1980) Geologic map of the northernmost Gore Range and southernmost Northern Park Range, Grand, Jackson and Routt Counties, Colorado. U. S. Geol. Surv. Map, 1-1114.Google Scholar
Steiger, R.H. and Jfiger, E. (1977) Convention on the use of decay constraints in geo- and cosmochronology. Earth Planet. Sci. Lett., 86, 359-62.CrossRefGoogle Scholar
Thompson, R.N., Morrison, M.A., Hendry, G.L. and Parry, S.J. (1984). An assessment of the relative roles of crust and mantle in magma genesis: an elemental approach. Phil. Trans. Roy. Soe. Lond., A310, 549-90.Google Scholar
Thompson, R.N., Leat, P.T., Dickin, A.P., Morrison, M.A., Hendry, G.L. and Gibson, S.A. (1989) Strongly potassic mafic magmas from lithospheric mantle sources during continental extension and heating: evidence from Miocene minettes of north-west Colorado, U.S.A. Earth Planet. Sci. Lett., 98, 139-5.CrossRefGoogle Scholar
Thompson, R.N., Gibson, S.A., Leat, P.T., Mitchell, J.G., Morrison, M.A., Hendry, G.L. and Dickin, A.P. (1993) Early Miocene continental extension-related basaltic magmatism at Walton Peak, northwest Colorado: further evidence on continental basalt genesis. J. Geol. Soc. Lond., 150, 277-92.CrossRefGoogle Scholar
Tweto, O. (1979a) The Rio Grande rift system in Colorado. In Rio Grande Rift: Tectonics and Magmatism (Riecker, R.E., ed.), Amer. Geophys. Union, 33-56.CrossRefGoogle Scholar
Tweto, O. (1979b) Geologic map of Colorado. Scale 1:500,000. U. S. Geol. Surv. Map. Google Scholar
Venturelli, G., Capedri, S., Barbieri, M., Toscani, L., Salvioli-Mariani, E. and Zerbi, M. (1991). The Jumilla lamproite revisited: a petrological oddity. Europ. J. Mineral., 3, 123-45.CrossRefGoogle Scholar
von Blanckenburg, F. and Davies, J.H. (1995) Slab breakoff: a model for syncollisional magmatism and tectonics in the Alps. Tectonics, 14, 120—31.CrossRefGoogle Scholar
Wagner, C. (1987) Contributions a l'étude minéralogi-que et géochimique des roches hyperalcalines potassiques. Lamproites et roches voisines. Unpublished Thèse de Doctorate d'lÉtat, Université P. et M. Curie, 87-23, 273 pp.Google Scholar
Wagner, C. and Velde, D. (1986) The mineralogy of K-richterite-bearing lamproites. Amer. Mineral., 71, 17-37.Google Scholar
Wagner, C. and Velde, D. (1987) Aluminous spinels in lamproites: occurrence and probable significance. Amer. Mineral., 72, 689-9.Google Scholar
Wendlandt, R.F. (1977) Barium-phlogopite from Haystack Butte, Highwood Mountains, Montana. Ann. Rept. Carnegie Inst. Wash. Ybk., 76, 534-9.Google Scholar
Wilkinson, J.F.G. and Hensel, H.D. (1994) Nephelines and analcimes in some alkaline igneous rocks. Contrib. Mineral. Petrol., 118, 79-91.CrossRefGoogle Scholar
Wilkinson, P., Mitchell, J.G., Cattermole, P.J. and Downie, C. (1986) Volcanic chronology of the Meru-Kilimanjaro region, northern Tanzania. J. Geol. Soc. Lond., 143, 601-5CrossRefGoogle Scholar
Woolley, A.R., Bergman, S.C., Edgar, A.D., Le Bas, M.J., Mitchell, R.H., Rock, N.M.S. and Scott Smith, B.H. (1996) Classification of lamprophyres, lamproites, kimberlites, and the kalsilitic, melilitic and leucitic rocks. Canad. Mineral., 34, 175—86.Google Scholar