Skip to main content Accessibility help
×
Home

Effects of fluid flow, cooling and deformation as recorded by 40Ar/39Ar, Rb–Sr and zircon fission track ages in very low- to low-grade metamorphic rocks in Avalonian SE Cape Breton Island (Nova Scotia, Canada)

  • ARNE P. WILLNER (a1) (a2), SANDRA M. BARR (a3), JOHANNES GLODNY (a4), HANS-JOACHIM MASSONNE (a1), MASAFUMI SUDO (a5), STUART N. THOMSON (a6), CEES R. VAN STAAL (a7) and CHRIS E. WHITE (a8)...

Abstract

40Ar/39Ar in situ UV laser ablation of white mica, Rb–Sr mineral isochrons and zircon fission track dating were applied to determine ages of very low- to low-grade metamorphic processes at 3.5±0.4 kbar, 280±30°C in the Avalonian Mira terrane of SE Cape Breton Island (Nova Scotia). The Mira terrane comprises Neoproterozoic volcanic-arc rocks overlain by Cambrian sedimentary rocks. Crystallization of metamorphic white mica was dated in six metavolcanic samples by 40Ar/39Ar spot age peaks between 396±3 and 363±14 Ma. Rb–Sr systematics of minerals and mineral aggregates yielded two isochrons at 389±7 Ma and 365±8 Ma, corroborating equilibrium conditions during very low- to low-grade metamorphism. The dated white mica is oriented parallel to foliations produced by sinistral strike-slip faulting and/or folding related to the Middle–Late Devonian transpressive assembly of Avalonian terranes during convergence and emplacement of the neighbouring Meguma terrane. Exhumation occurred earlier in the NW Mira terrane than in the SE. Transpression was related to the closure of the Rheic Ocean between Gondwana and Laurussia by NW-directed convergence. The 40Ar/39Ar spot age spectra also display relict age peaks at 477–465 Ma, 439 Ma and 420–428 Ma attributed to deformation and fluid access, possibly related to the collision of Avalonia with composite Laurentia or to earlier Ordovician–Silurian rifting. Fission track ages of zircon from Mira terrane samples range between 242±18 and 225±21 Ma and reflect late Palaeozoic reburial and reheating close to previous peak metamorphic temperatures under fluid-absent conditions during rifting prior to opening of the Central Atlantic Ocean.

Copyright

Corresponding author

Author for correspondence: arne.willner@rub.de

References

Hide All
Abati, J., Aghzer, A.M., Gerdes, A. & Ennih, N. 2012. Insights on the crustal evolution of the West African Craton from Hf isotopes in detrital zircons from the Anti-Atlas belt. Precambrian Research 183, 263–74.
Barr, S. M. 1993. Geochemistry and tectonic setting of late Precambrian volcanic and plutonic rocks in southeastern Cape Breton Island, Nova Scotia. Canadian Journal of Earth Science 30, 1147–54.
Barr, S. M., Dunning, G. R., Raeside, R. P. & Jamieson, R. A. 1990. Contrasting U-Pb ages from plutons in the Bras d’Or and Mira terranes of Cape Breton Island, Nova Scotia. Canadian Journal of Earth Science 27, 1200–8.
Barr, S. M., Grammatikopoulos, A. L. & Dunning, G. R. 1994. Early Carboniferous gabbro and basalt in the St. Peters area, southern Cape Breton Island, Nova Scotia. Atlantic Geology 30, 247–58.
Barr, S. M. & Macdonald, A. S. 1992. Devonian plutons in southeastern Cape Breton Island, Nova Scotia. Atlantic Geology 28, 101–13.
Barr, S. M. & Raeside, R. P. 1989. Tectonostratigraphic terranes in Cape Breton Island, Nova Scotia. Implications for the configuration of the northern Appalachian Orogen. Geology 17, 822–5.
Barr, S. M., White, C. E., Hames, W. E. & Reynolds, P. H. 2014. Age and provenance of detrital muscovite from the Ediacaran-Cambrian boundary zone in Atlantic Canada: Implications for the paleogeographic position of Avalonia. GAC-MAC Conference Fredericton, Program with Abstracts 37, 1819.
Barr, S. M., White, C. E. & Macdonald, A. S. 1996. Stratigraphy, tectonic setting, and geologic history of Late Precambrian volcanic-sedimentary-plutonic belts in southeastern Cape Breton Island, Nova Scotia. Geological Survey of Canada Bulletin 468, 84 pp.
Beard, B. L., Medaris, L. G. Jr., Johnson, C. M., Jelinek, E., Tonika, J. & Riciputi, L. R. 1995. Geochronology and geochemistry of eclogites from the Mariánské Lázně Complex, Czech Republic: Implications for Variscan orogenesis. Geologische Rundschau 84, 552–67.
Bevier, M. L., Barr, S. M., White, C. E. & Macdonald, A. S. 1993. U-Pb geochronologic constraints on the volcanic evolution of the Mira (Avalon) terrane, southeastern Cape Breton Island, Nova Scotia. Canadian Journal of Earth Science 30, 110.
Boehner, R. C., Adams, G. C. & Giles, P. S. 2002. Karst geology in the salt-bearing Windsor Group evaporites and controls on the origin of gypsum deposits in south-central Cape Breton Island, Nova Scotia. Mineral Resources Branch, Nova Scotia Department of Natural Resources, Report of Activities 2003–1, 9–24.
Brix, M. R., Stöckhert, B., Seidel, E., Theye, T., Thomson, S. N. & Küster, M. 2002. Thermobarometric data from a fossil zircon partial annealing zone in high pressure-low temperature rocks of eastern and central Crete, Greece. Tectonophysics 349, 309–26.
Cohen, K. M., Finney, S. & Gibbard, P. L. 2013. International Chronostratigraphic Chart, Version 01/2013. International Commision on Stratigraphy.
Díez Fernández, R., Foster, D. A., Gómez Barreiro, J. & Alonso-García, M. 2013. Rheological control on the tectonic evolution of a continental suture zone: the Variscan example from NW Iberia (Spain). International Journal of Earth Science 102, 1305–19.
Díez Fernández, R., Martínez Catalán, J. R., Arenas, R. & Abati, J. 2011. Tectonic evolution of a continental subduction-exhumation channel: Variscan structure of the basal allochthonous units in NW Spain. Tectonics 30, TC3009, 3001–22.
Dunn, A. M., Reynolds, P. H., Clarke, D. B. & Ugidos, J. M. 1998. A comparison of the age and composition of the Shelburne dyke, Nova Scotia, and the Messejana dyke, Spain. Canadian Journal of Earth Sciences 35, 1110–5.
Fielitz, W. & Mansy, J.-L. 1999. Pre- and synorogenic burial metamorphism in the Ardennes and neighbouring areas (Rhenohercynian zone, central European Variscides). Tectonophysics 309, 227–56.
Freeman, S. R., Butler, R. W. H., Cliff, R. A. & Rex, D. C. 1998. Direct dating of mylonite evolution: a multi-disciplinary geochronological study from the Moine Thrust Zone, NW Scotland. Journal of the Geological Society, London 155, 745–58.
Galbraith, R. F. & Laslett, G. M. 1993. Statistical models for mixed fission track ages. Nuclear Tracks and Radiation Measurements 21, 459–70.
Gibling, M. R., Culshaw, N., Rygel, M. C. & Pascucci, V. 2008. The Maritimes basin of Atlantic Canada: basin creation and destruction in the collisional zone of Pangea. Sedimentary Basins of the World 5, 211–44.
Giles, P. S., Naylor, R. D., Teniere, P. J., White, C. E., Barr, S. M., DeMont, G. J. & Force, E. R. 2010. Bedrock geology map of the Port Hawkesbury area, Part of NTS Sheets 11F/06, 11F/07, 11F/10, 11F/11 and 11F/15, Inverness, Richmond, Guysborough, and Antigonish Counties, Nova Scotia (scale 1:50 000). Nova Scotia Department of Natural Resources, Mineral Resources Branch, Open File Map Me 2010–006.
Glodny, J., Lohrmann, J., Echtler, H., Gräfe, K., Seifert, W., Collao, S. & Figueroa, O. 2005. Internal dynamics of a paleoaccretionary wedge: insights from combined isotope tectonochronology and sandbox modelling of the South–Central Chilean forearc. Earth and Planetary Science Letters 231, 2339.
Glodny, J., Ring, U. & Kühn, A. 2008. Coeval high-pressure metamorphism, thrusting, strike-slip, and extensional shearing in the Tauern Window, Eastern Alps. Tectonics 27, TC4004.
Green, P. F., Duddy, I. R., Laslett, G. M., Hegarty, K. A., Gleadow, A. J. W. & Lovering, J. F. 1989. Thermal annealing of fission tracks in apatite, 4. Quantitative modelling techniques and extension to geological timescales. Chemical Geology 79, 155–82.
Grist, A. M. & Zentilli, M. 2003. Post-Paleocene cooling in the southern Canadian Atlantic region: evidence from apatite fission track models. Canadian Journal of Earth Science 40, 1279–97.
Hibbard, J. P., van Staal, C. R., Rankin, D. & Williams, H. 2006. Lithotectonic map of the Appalachian orogen (north), Canada–United States of America. Geological Survey of Canada Map 2041A, scale 1:1,500,000.
Hurford, A. J. 1990. Standardization of fission-track dating calibration: recommended by the Fission-track Working Group of the IUGS Subcommission on Geochronology. Chemical Geology (Isotope Geoscience Section) 80, 171–8.
Hurford, A. J. & Green, P. F. 1983. The zeta age calibration of fission-track dating. Isotope Geoscience 1, 285317.
Hutchinson, R. D. 1952. The Stratigraphy and Trilobite Faunas of the Cambrian Sedimentary Rocks of Cape Breton Island, Nova Scotia. Geological Survey of Canada, Memoir no. 263, 124 pp.
Inger, S. & Cliff, R. A. 1994. Timing of metamorphism in the Tauern Window, Eastern Alps: Rb-Sr ages and fabric formation. Journal of Metamorphic Geology 12, 695707.
Ishizuka, O., Yuasa, M. & Uto, K. 2002. Evidence of porphyry copper-type hydrothermal activity from a submerged remnant back-arc volcano of the Izu-Bonin arc: implication for the volcanotectonic history of backarc seamounts. Earth and Planetary Science Letters 198, 381–99.
Keen, C. E., MacLean, B. C. & Kay, W. A. 1991. A deep seismic reflection profile across the Nova Scotia continental margin, offshore eastern Canada. Canadian Journal of Earth Sciences 28, 1112–20.
Kelley, S. P., Arnaud, N. O. & Turner, S. P. 1994. High spatial resolution 40Ar/39Ar investigations using an ultra-violet laser probe extraction technique. Geochimica Cosmochimica Acta 58, 3519–25.
Kroner, U. & Romer, R. L. 2013. Two plates - many subduction zones: the Variscan orogeny reconsidered. Gondwana Research 24, 298329.
Labails, C., Olivet, J. L., Aslanian, D. & Roest, W. R. 2010. An alternative early opening scenario for the Central Atlantic Ocean. Earth and Planetary Science Letters 297, 355–68.
Landing, E. 1991. Upper Precambrian through Lower Cambrian of Cape Breton Island: faunas, paleoenvironments, and stratigraphic revision. Journal of Paleontology 65, 570–95.
Ludwig, K. 2009. Isoplot v. 3.71: A Geochronological Toolkit for Microsoft Excel. Berkeley Geochronology Center, Berkeley, California, Special Publication 4, 70 pp.
Macdonald, A. S. & Barr, S. M. 1993 a. Geological setting and depositional environment of the Stirling Group of southeastern Cape Breton Island, Nova Scotia. Atlantic Geology 29, 137–47.
Macdonald, A. S. & Barr, S. M. 1993 b. The Blue Mountain polymetallic skarn and associated porphyry dykes, southeastern Cape Breton Island, Nova Scotia. In Mineral Deposit Studies in Nova Scotia II (ed. Sangster, A. L.), pp. 318. Geological Survey of Canada, Paper 91–9.
Martel, A. T. & Gibling, M. R. 1995. Stratigraphy and tectonic history of the Upper Devonian to Lower Carboniferous Horton Bluff Formation, Nova Scotia. Atlantic Geology 32, 1338.
Massonne, H.-J. 2005. Involvement of crustal material in delamination of the lithosphere after continent-continent collision. International Geology Review 47, 792804.
Massonne, H.-J. & O’Brien, P. J. 2003. The Bohemian Massif and the NW Himalaya. In Ultrahigh Pressure Metamorphism (eds Carswell, D. A. & Compagnoni, R.), pp. 145–87. EMU Notes in Mineralogy no. 5.
Massonne, H.-J. & Willner, A. P. 2008. Phase relations and dehydration behaviour of psammopelite and mid-ocean ridge basalt at very low-grade to low-grade metamorphic conditions. European Journal of Mineralogy 20, 867–79.
McDougall, I. & Harrison, T. M. 1999. Geochronology and Thermochronology by the 40Ar/39Ar Method. Oxford: Oxford University Press, 269 pp.
McMullin, D. W. A., Barr, S. M. & Raeside, R. P. 2010. Very low- and low-grade metamorphism of mafic volcanic rocks of the Mira terrane (Avalonia), southeastern Cape Breton Island, Nova Scotia. Atlantic Geology 46, 95126.
Müller, W., Dallmeyer, R. D., Neubauer, F. & Thöni, M. 1999. Deformation-induced resetting of Rb/Sr and 40Ar/39Ar mineral systems in a low-grade, polymetamorphic terrane (Eastern Alps Austria). Journal of the Geological Society, London 156, 261–78.
Murphy, J. B. & Collins, A. S. 2008. 40Ar–39Ar white mica ages reveal Neoproterozoic/Paleozoic provenance and an Alleghanian overprint in coeval Upper Ordovician–Lower Devonian rocks of Meguma and Avalonia. Tectonophysics 461, 265–76.
Murphy, J. B., Fernandez-Suarez, J., Keppie, J. D. & Jeffries, T. E. 2004. Contiguous rather than discrete Paleozoic histories for the Avalon and Meguma Terranes based on detrital zircon data. Geology 32, 585–8.
Murphy, J. B., van Staal, C. R. & Keppie, J. D. 1999. Middle to late Paleozoic Acadian orogeny in the northern Appalachians: A Laramide-style plume-modified orogeny? Geology 27, 653–6.
Murphy, J. B., Waldron, J. W. F., Kontak, D. J., Pe-Piper, G. & Piper, D. J. W. 2011. Minas Fault Zone: Late Paleozoic history of an intra-continental orogenic transform fault in the Canadian Appalachians. Journal of Structural Geology 33, 312–28.
Palacios, T., Jensen, S., Barr, S. M. & White, C. E. 2009. Acritarchs from the MacLean Brook Formation, southeastern Cape Breton Island, Nova Scotia: new data on middle Cambrian-Furongian acritarch zonation. Palaeogeography, Palaeoclimatology, Palaeoecology 273,123–41.
Pe-Piper, G. & Jansa, L. F. 1999. Pre-Mesozoic basement rocks offshore Nova Scotia, Canada: New constraints on the accretion history of the Meguma terrane. Geological Society of America Bulletin 111, 1773–91.
Pe-Piper, G. & Loncarevic, B. D. 1989. Offshore continuation of Meguma terrane, southwestern Nova Scotia. Canadian Journal of Earth Sciences 26, 176–91.
Potter, J., Longstaffe, F. J. & Barr, S. M. 2008. Regional 18O-depletion of Neoproterozoic igneous rocks from Avalonia, Cape Breton Island and southern New Brunswick, Canada. Geological Society of America Bulletin 120, 347–67.
Potter, J., Longstaffe, F. J., Barr, S. M., Thompson, M. D. & White, C. E. 2008. Altering Avalonia: oxygen isotopes and terrane distinction in the Appalachian peri-Gondwanan realm. Canadian Journal of Earth Science 45, 815–25.
Raeside, S. M. & Barr, S. M. 1990. Geology and tectonic development of the Bras d’Or suspect terrane, Cape Breton Island, Nova Scotia. Canadian Journal of Earth Sciences 27, 1371–81.
Rahn, M. K., Brandon, M. T., Batt, G. E. & Garver, J. I. 2004. A zero-damage model for fission-track annealing in zircon. American Mineralogist 89, 473–84.
Ravenhurst, C. E., Donelick, R., Zentilli, M., Reynolds, P. H. & Beaumont, C. 1990. A fission track pilot study of thermal effects of rifting on the onshore Nova Scotian margin, Canada. Nuclear Tracks Radiation Measurements 17, 373–8.
Ravenhurst, C. E., Reynolds, P. H., Zentilli, M., Krueger, H. W. & Blenkinsop, J. 1989. Formation of Carboniferous Pb-Zn and barite mineralization from basin-derived fluids, Nova Scotia, Canada. Economic Geology 84, 1471–88.
Reynolds, P. H., Barr, S. M. & White, C. E. 2009. Provenance of detrital muscovite in Cambrian Avalonia of Maritime Canada: 40Ar/39Ar ages and chemical compositions. Canadian Journal of Earth Sciences 46, 169–80.
Ring, U., Brandon, M. T., Willett, S. D. & Lister, G. S. 1999. Exhumation processes. In Exhumation Processes: Normal Faulting, Ductile Flow and Erosion (eds Ring, U., Brandon, M. T., Lister, G. S. & Willett, S. D.), pp. 127. Geological Society of London, Special Publication no. 154.
Ryan, R. J. & Zentilli, M. 1993. Allocyclic and thermochronological constraints on the evolution of the Maritimes Basin of eastern Canada. Atlantic Geology 29, 187–97.
Sanford, B. V. & Grant, A. C. 1990. Bedrock geological mapping and basin studies in the Gulf of St. Lawrence. Current research, part B. Geological Survey of Canada, Paper 90–1B, 3342.
Stampfli, G. M. & Borel, G. D. 2002. A plate tectonic model for the Paleozoic and Mesozoic constrained by dynamic plate boundaries and restored synthetic oceanic isochrons. Earth and Planetary Science Letters 196, 1733.
Steiger, R. H. & Jäger, E. 1977. Subcommission on geochronology: convention on the use of decay constants in geo- and cosmochronology. Earth and Planetary Science Letters 36, 359–62.
Stosch, H.-G. & Lugmair, G. W. 1990. Geochemistry and evolution of MORB-type eclogites from the Münchberg Massif, southern Germany. Earth and Planetary Science Letters 99, 230–49.
Tagami, T., Galbraith, R. F., Yamada, R. & Laslett, G. M. 1998. Revised annealing kinetics of fission tracks in zircon and geological implications. In Advances in Fission-Track Geochronology (eds Van den Haute, P. & De Corte, F.), pp. 99112. Dordrecht: Kluwer Academic Publishers.
Thomson, S. N. & Ring, U. 2006. Thermochronologic evaluation of postcollision extension in the Anatolide Orogen, western Turkey. Tectonics 25, TC3005, doi: 10.1029/2005TC001833.
Thomson, S. N., Stoeckhert, B. & Brix, M. R. 1998. Thermochronology of the high-pressure metamorphic rocks of Crete, Greece: implications for the speed of tectonic processes. Geology 26, 259–62.
Uto, K., Ishizuka, O., Matsumoto, A., Kamioka, H. & Togashi, S. 1997. Laser-heating 40Ar/39Ar dating system of the Geological Survey of Japan: system outlines and preliminary results. Bulletin of the Geological Survey of Japan 48, 2346.
van Staal, C. R. 2007. Pre-Carboniferous tectonic evolution and metallogeny of the Canadian Appalachians. In Mineral Deposits of Canada: A Synthesis of Major Deposit-Types, District Metallogeny, the Evolution of Geological Provinces, and Exploration Methods (ed. Goodfellow, W. D.), pp. 793818. Geological Association of Canada, Mineral Deposits Division, Special Publication no. 5.
van Staal, C. R. & Barr, S. M. 2012. Lithospheric architecture and tectonic evolution of the Canadian Appalachians and associated Atlantic margin. Chapter 2 In Tectonic Styles in Canada: the LITHOPROBE Perspective (eds Percival, J. A., Cook, F. A. & Clowes), pp. 4195. Geological Association of Canada, Special Paper no. 49.
van Staal, C. R., Whalen, J. B., Valverde-Vaquero, P., Zagorevski, A. & Rogers, N. 2009. Pre-Carboniferous, episodic accretion-related, orogenesis along the Laurentian margin of the northern Appalachians. In Ancient Orogens and Modern Analogues (eds Murphy, J. B., Keppie, J. D. & Hynes, A. J.), pp. 271316. Geological Society London, Special Publication no. 327.
Vermeesch, P. 2009. RadialPlotter: a Java application for fission track, luminescence and other radial plots. Radiation Measurements 44, 409–10.
Villa, I. M. 1998. Isotopic closure. Terra Nova 10, 42–7.
Villa, I. M. 2006. From nanometer to megameter: Isotopes, atomic-scale processes, and continent-scale tectonic models. Lithos 87, 155–73.
von Quadt, A. & Gebauer, D. 1993. Sm-Nd and U-Pb dating of eclogites and granulites from the Oberpfalz, NE Bavaria, Germany. Chemical Geology 109, 317–39.
Waldron, J. W. F., Schofield, D. I., White, C. E. & Barr, S. M. 2011. Cambrian successions of the Meguma Terrane, Nova Scotia, Canada, and Harlech Dome, North Wales, UK: dispersed fragments of a peri-Gondwanan basin? Journal of the Geological Society, London 168, 8398.
Waldron, J. W. F., White, C. E., Barr, S. M., Simonetti, A. & Heaman, L. M. 2009. Provenance of the Meguma terrane, Nova Scotia: rifted margin of early Paleozoic Gondwana. Canadian Journal of Earth Sciences 46, 18.
White, C. E. & Barr, S. M. 1998. Stratigraphy and tectonic significance of the Lower to Middle Devonian McAdams Lake Formation, Cape Breton Island, Nova Scotia. Atlantic Geology 34, 133–45.
White, C. E. & Barr, S. M. 2012. The new Meguma: stratigraphy, metamorphism, paleontology and provenance. Field Trip B-5, Geological Association of Canada and Mineralogical Association of Canada, 68 pp.
White, C. E., Barr, S. M. & Ketchum, J. W. F. 2003. New age controls on rock units in pre-Carboniferous basement blocks in southwestern Cape Breton Island and adjacent mainland Nova Scotia. Nova Scotia Department of Natural Resources, Minerals and Energy Branch, Report of Activities 2002, Report ME 2003–1, 163–78.
White, C. E., Barr, S. M., Reynolds, P. H., Grace, E. & McMullin, D. W. A. 2006. The Pocologan Metamorphic Suite: High-pressure metamorphism in a Silurian fore-arc complex, Kingston Terrane, southern New Brunswick. Canadian Mineralogist 44, 905–27.
Wijbrans, J. R. & McDougall, I. 1986. 40Ar/39Ar dating of white micas from an Alpine high-pressure belt on Naxos (Greece): resetting of the argon isotopic system. Contributions to Mineralogy and Petrology 93, 187–94.
Willner, A. P., Gerdes, A., Massonne, H.-J., Barr, S. M. & White, C. E. 2013 a. Origin and crustal evolution of the Avalonian microcontinent: evidence from a U-Pb and Lu-Hf isotope study of detrital zircon in Nova Scotia, Canada, and East Belgium. Journal of the Geological Society, London 170, 769–84.
Willner, A. P., Massonne, H.-J., Barr, S. M. & White, C. E. 2013 b. Very low- to low-grade metamorphic processes related to the collisional assembly of Avalonia in SE Cape Breton Island (Nova Scotia, Canada). Journal of Petrology 54, 1849–74.
Willner, A. P., Massonne, H.-J., Ring, U., Sudo, M. & Thomson, S. N. 2012. P–T evolution and timing of a late Palaeozoic fore-arc system and its heterogeneous Mesozoic overprint in north-central Chile (latitudes 31–32°S).Geological Magazine 149, 177207.
Willner, A. P., Sepúlveda, F. A., Hervé, F., Massonne, H.-J. & Sudo, M. 2009. Conditions and timing of pumpellyite-actinolite facies metamorphism in the Early Mesozoic frontal accretionary prism of the Madre de Dios Archipelago (50°20¢S; S-Chile). Journal of Petrology 50, 2127–55.
Willner, A. P., Thomson, S. N., Kröner, A., Wartho, J. A., Wijbrans, J. & Hervé, F. 2005. Time markers for the evolution and exhumation history of a late Palaeozoic paired metamorphic belt in central Chile (34°–35°30°S). Journal of Petrology 46, 1835–58.
Zeh, A. & Gerdes, A. 2010. Baltica- and Gondwana-derived sediments in the Mid-German Crystalline Rise (Central Europe): implications for the closure of the Rheic Ocean. Gondwana Research 17, 254–63.

Keywords

Type Description Title
EXCEL
Supplementary materials

Willner Supplementary Material
Table S1

 Excel (30 KB)
30 KB

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed