Geochronological evidence for post-Variscan cooling and uplift of the Carnmenellis granite, SW England

Y. CHEN; M. A. ZENTILLI; A. H. CLARK; E. FARRAR; A. M. GRIST; J. WILLIS-RICHARDS

doi:10.1144/gsjgs.153.2.0191

Abstract

Apatite fission-track (AFT) dates for granitic samples from surface exposures and deep boreholes in the 293.3 ± 1.2 Ma Carnmenellis granite, west Cornwall, decrease radically from 130 ± 28 (2σ) Ma at surface to 26 ± 6 Ma at c. 2500 m depth, a trend accompanied by a decrease in mean track length from 12.99 ± 0.80μm to 9.83 ± 0.62 μm. In contrast, ⁴⁰Ar–³⁹Ar apparent age plateaux for muscovite decrease only from 288.5 ± 1.0 Ma at surface to 286.1 ± 1.0 Ma at c. 2500 m depth. The small difference in the muscovite ages may record the presence of a slightly younger intrusive phase at depth, but it is apparent that the preserved upper 2.5 km of the pluton cooled rapidly through c. 320°C. However, thermal modelling of the AFT data delimits a distinct fast-cooling event at c. 137–155 Ma, exhibiting a satisfactory correlation with a major regional uplift episode in Late Jurassic/Early Cretaceous times recorded by the sedimentary basins flanking the Cornubian massif.

References

1. Bristow C. M.,
2. Exley C. S.
(1994) Historical and geological aspects of the china clay industry of south-west England. Transactions of the Royal Geological Society of Cornwall 21:247–314.
OpenUrl
Bromley, A.V. 1989. The Cornubian Orefield. International Association of Geochemistry and Cosmochemistry, 6th International Symposium on Water–Rock Interaction. Malvern, U.K., Field Guide, Camborne School of Mines, Redruth.
Camborne School of Mires 1986. Geothermal Energy Research Project: Lithology, Mineralogy and Structure. Report 2–58.
1. Charoy B.
(1986) The genesis of the Cornubian batholith (southwest England): the example of the Carnmenellis pluton. Journal of Petrology 27:571–604.
OpenUrl CrossRef Web of Science
1. Chen Y.,
2. Clark A. H.,
3. Farrar E.,
4. Bromley A.V.,
5. Hodgson M.J.,
6. Willis-Richards J.
(1991) ⁴⁰Ar/³⁹Ar geochronology of granitic intrusion and Sn-Cu(-W) mineralization Carn Brea-Carn Marth-Carnmenellisarea, Cornwall, UK (abstract) Geologicol Society of America, Abstracts with Programs 23:A293.
OpenUrl
1. Chen Y.,
2. Clark A. H.,
3. Farrar E.,
4. Wasteneys H. A. H. P.,
5. Hodgson M. J.,
6. Bromley A. V.
(1993) Diachronous and independent histories of plutonism and mineralization in the Cornubian Batholith, south-west England. Journal of the Geological Society, London 150:1183–1191.
OpenUrl Abstract/FREE Full Text
1. Chesley J. T.,
2. Halliday A. N.,
3. Snee L. W.,
4. Mezger K.,
5. Shepherd T. J.,
6. Scrivener R. C.
(1993) Thermochronology of the Cornubian batholith in southwest England: implications for pluton emplacement and protracted hydrothermal mineralization. Geochimica et Cosmochimica Acta 57:1817–1835.
OpenUrl CrossRef Web of Science
1. Clark A. H.,
2. Chen Y.,
3. Farrar E.,
4. Northcote B.,
5. Wasteneys H. A. H. P.,
6. Hodgson M. J.,
7. Bromley A.
(1994) Refinement of the time/space relationships of intrusion and hydrothermal activity in the Cornubian batholith (extended abstract). Proceedings of the Ussher Society 8:345.
OpenUrl
1. Clark A. H.,
2. Chen Y.,
3. Farrar E.,
4. Wasteneys H. A. H. P.,
5. Stimac J. A.,
6. Hodgson M. J.,
7. Willis-Richards J.,
8. Bromley A. V.
(1993) The Cornubian Sn-Cu (-As, W) metallogenetic province: product of a 30 my history of discrete and concomitant anatectic, intrusive and hydrothermal events Proceedings of the Ussher Society 8:112–116.
OpenUrl
Cope, J.C.W., Ingham, J.K. & Rawson, P.F. (eds) 1992. Atlas of Palaeogeography and Lithofacies. Geological Society, London, Memoir, 13.
1. Dangerfield J.,
2. Hawkes J. R.
(1981) The Variscan granites of SW England: additional information. Proceedings of the Ussher Society 5:116–120.
OpenUrl
1. Darbyshire D. P. F.,
2. Shepherd T. J.
(1985) Chronology of granite magmatism and associated mineralisation, SW England. Journal of the Geological Society, London 142:1159–1177.
OpenUrl Abstract/FREE Full Text
Edmonds, E.A., McKeown, M.C. & Williams, M. 1975. British regional geology: South-West England (4th edition). London: HMSO for Institute of Geological Sciences.
Evans, C.D.R. 1990. The geology of the western English Channel and its western approaches. British Geological Survey United Kingdom Offshore Regional Report.
1. Gleadow A. J. W.,
2. Duddy I. R.,
3. Lovering J. F.
(1983) Fission track analysis: A new tool for the evaluation of thermal histories and hydrocarbon potential. Australian Petroleum Exploration Association Journal 23:93–102.
OpenUrl
Goode, A.J.J. & Taylor, R.T. 1988. Geology of the Country around Penzance. British Geological Survey Memoir.
1. Green P. F.
(1981) A new look at statistics in fission track dating. Nuclear Tracks 5:71–86.
OpenUrl
1. Green P. F.,
2. Duddy I. R.,
3. Laslett G. M.,
4. Hegarty K. A.,
5. Gleadow A. J. W.,
6. Lovering J. F.
(1989) Thermal annealing of fission tracks in apatite: 4 Quantitative modelling techniques and extension to geologic timescales. Chemical Geology (Isotope Geosciences Section) 79:155–182.
OpenUrl CrossRef
1. Harrison T. M.,
2. McDougall I.
(1980) Investigations of an intrusive contact northwest of Nelson, New Zealand-I Thermal, chronological and isotope constraints. Geochimica et Cosmochimica Acta 44:1985–2003.
OpenUrl CrossRef Web of Science
1. Hurford A. J.
(1990) Standardization of fission track dating calibration: Recommendation of the Fission Track Working Group of the I.U.G.S. Subcommission on Geochronology. Chemical Geology (Isotope Geosciences Section) 80:171–178.
OpenUrl CrossRef
Leveridge, B.E., Holder, M.T. & Goode, A.J.J. 1990. Geology of the Country around Falmouth. British Geological Survey Memoir.
1. Parrish R. R.
(1990) U–Pb dating of monazite and its application to geological problems. Canadian Journal of Earth Sciences 27:1431–1450.
OpenUrl Abstract
1. Ravenhurst C.E.,
2. Donelick R.A
(1992) in Low Temperature Thermochronology, Fission track thermochronology, eds Zentilli M., Reynolds P.H. Mineralogical Association of Canada short course handbook, pp 21–42.
1. Roberts D. G.
(1989) Basin inversion in and around the British Isles. in Inversion Tectonics Geological Society, London, Special Publications, eds Cooper M. A., Williams G. D. 44:131–150.
OpenUrl CrossRef
1. Snee L. W.,
2. Sutter J. F.,
3. Kelly W. C.
(1988) Thermochronology of economic mineral deposits: dating the stages of mineralization at Panasqueira by high-precision ⁴⁰Ar/³⁹ Ar age spectrum techniques on muscovite. Economic Geology 83:335–354.
OpenUrl Abstract/FREE Full Text
1. Thorpe R. S.
(1987) Permian K-rich volcanic rocks of Devon: petrogenesis, tectonic setting and geological significance. Transactions of the Royal Society of Edinburgh 77:361–366.
OpenUrl
1. Willet S.D.
(1992) in Low Temperature Thermochronology, Modelling thermal annealing of fission tracks in apatite, eds Zentilli M., Reynolds P.H. Mineralogical Association of Canada short course handbook, pp 43–72.
1. Willis-Richards J.,
2. Jackson N. J.
(1989) Evolution of the Cornubian ore field: Part I. Batholith modeling and ore distribution. Economic Geology 84:1078–1100.
OpenUrl Abstract/FREE Full Text
1. Ziegler P. A.
(1987) Celtic Sea-Western Approaches area: an overview. Tectonophysics 137:285–289.
OpenUrl CrossRef Web of Science

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[1] Bristow C. M.,
Exley C. S.
(1994) Historical and geological aspects of the china clay industry of south-west England. Transactions of the Royal Geological Society of Cornwall 21:247–314.
OpenUrl

[2] Bristow C. M.,

[3] Exley C. S.

[4] Bromley, A.V. 1989. The Cornubian Orefield. International Association of Geochemistry and Cosmochemistry, 6th International Symposium on Water–Rock Interaction. Malvern, U.K., Field Guide, Camborne School of Mines, Redruth.

[5] Camborne School of Mires 1986. Geothermal Energy Research Project: Lithology, Mineralogy and Structure. Report 2–58.

[6] Charoy B.
(1986) The genesis of the Cornubian batholith (southwest England): the example of the Carnmenellis pluton. Journal of Petrology 27:571–604.
OpenUrl CrossRef Web of Science

[7] Charoy B.

[8] Chen Y.,
Clark A. H.,
Farrar E.,
Bromley A.V.,
Hodgson M.J.,
Willis-Richards J.
(1991) ⁴⁰Ar/³⁹Ar geochronology of granitic intrusion and Sn-Cu(-W) mineralization Carn Brea-Carn Marth-Carnmenellisarea, Cornwall, UK (abstract) Geologicol Society of America, Abstracts with Programs 23:A293.
OpenUrl

[9] Chen Y.,

[10] Clark A. H.,

[11] Farrar E.,

[12] Bromley A.V.,

[13] Hodgson M.J.,

[14] Willis-Richards J.

[15] Chen Y.,
Clark A. H.,
Farrar E.,
Wasteneys H. A. H. P.,
Hodgson M. J.,
Bromley A. V.
(1993) Diachronous and independent histories of plutonism and mineralization in the Cornubian Batholith, south-west England. Journal of the Geological Society, London 150:1183–1191.
OpenUrl Abstract/FREE Full Text

[16] Chen Y.,

[17] Clark A. H.,

[18] Farrar E.,

[19] Wasteneys H. A. H. P.,

[20] Hodgson M. J.,

[21] Bromley A. V.

[22] Chesley J. T.,
Halliday A. N.,
Snee L. W.,
Mezger K.,
Shepherd T. J.,
Scrivener R. C.
(1993) Thermochronology of the Cornubian batholith in southwest England: implications for pluton emplacement and protracted hydrothermal mineralization. Geochimica et Cosmochimica Acta 57:1817–1835.
OpenUrl CrossRef Web of Science

[23] Chesley J. T.,

[24] Halliday A. N.,

[25] Snee L. W.,

[26] Mezger K.,

[27] Shepherd T. J.,

[28] Scrivener R. C.

[29] Clark A. H.,
Chen Y.,
Farrar E.,
Northcote B.,
Wasteneys H. A. H. P.,
Hodgson M. J.,
Bromley A.
(1994) Refinement of the time/space relationships of intrusion and hydrothermal activity in the Cornubian batholith (extended abstract). Proceedings of the Ussher Society 8:345.
OpenUrl

[30] Clark A. H.,

[31] Chen Y.,

[32] Farrar E.,

[33] Northcote B.,

[34] Wasteneys H. A. H. P.,

[35] Hodgson M. J.,

[36] Bromley A.

[37] Clark A. H.,
Chen Y.,
Farrar E.,
Wasteneys H. A. H. P.,
Stimac J. A.,
Hodgson M. J.,
Willis-Richards J.,
Bromley A. V.
(1993) The Cornubian Sn-Cu (-As, W) metallogenetic province: product of a 30 my history of discrete and concomitant anatectic, intrusive and hydrothermal events Proceedings of the Ussher Society 8:112–116.
OpenUrl

[38] Clark A. H.,

[39] Chen Y.,

[40] Farrar E.,

[41] Wasteneys H. A. H. P.,

[42] Stimac J. A.,

[43] Hodgson M. J.,

[44] Willis-Richards J.,

[45] Bromley A. V.

[46] Cope, J.C.W., Ingham, J.K. & Rawson, P.F. (eds) 1992. Atlas of Palaeogeography and Lithofacies. Geological Society, London, Memoir, 13.

[47] Dangerfield J.,
Hawkes J. R.
(1981) The Variscan granites of SW England: additional information. Proceedings of the Ussher Society 5:116–120.
OpenUrl

[48] Dangerfield J.,

[49] Hawkes J. R.

[50] Darbyshire D. P. F.,
Shepherd T. J.
(1985) Chronology of granite magmatism and associated mineralisation, SW England. Journal of the Geological Society, London 142:1159–1177.
OpenUrl Abstract/FREE Full Text

[51] Darbyshire D. P. F.,

[52] Shepherd T. J.

[53] Edmonds, E.A., McKeown, M.C. & Williams, M. 1975. British regional geology: South-West England (4th edition). London: HMSO for Institute of Geological Sciences.

[54] Evans, C.D.R. 1990. The geology of the western English Channel and its western approaches. British Geological Survey United Kingdom Offshore Regional Report.

[55] Gleadow A. J. W.,
Duddy I. R.,
Lovering J. F.
(1983) Fission track analysis: A new tool for the evaluation of thermal histories and hydrocarbon potential. Australian Petroleum Exploration Association Journal 23:93–102.
OpenUrl

[56] Gleadow A. J. W.,

[57] Duddy I. R.,

[58] Lovering J. F.

[59] Goode, A.J.J. & Taylor, R.T. 1988. Geology of the Country around Penzance. British Geological Survey Memoir.

[60] Green P. F.
(1981) A new look at statistics in fission track dating. Nuclear Tracks 5:71–86.
OpenUrl

[61] Green P. F.

[62] 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 geologic timescales. Chemical Geology (Isotope Geosciences Section) 79:155–182.
OpenUrl CrossRef

[63] Green P. F.,

[64] Duddy I. R.,

[65] Laslett G. M.,

[66] Hegarty K. A.,

[67] Gleadow A. J. W.,

[68] Lovering J. F.

[69] Harrison T. M.,
McDougall I.
(1980) Investigations of an intrusive contact northwest of Nelson, New Zealand-I Thermal, chronological and isotope constraints. Geochimica et Cosmochimica Acta 44:1985–2003.
OpenUrl CrossRef Web of Science

[70] Harrison T. M.,

[71] McDougall I.

[72] Hurford A. J.
(1990) Standardization of fission track dating calibration: Recommendation of the Fission Track Working Group of the I.U.G.S. Subcommission on Geochronology. Chemical Geology (Isotope Geosciences Section) 80:171–178.
OpenUrl CrossRef

[73] Hurford A. J.

[74] Leveridge, B.E., Holder, M.T. & Goode, A.J.J. 1990. Geology of the Country around Falmouth. British Geological Survey Memoir.

[75] Parrish R. R.
(1990) U–Pb dating of monazite and its application to geological problems. Canadian Journal of Earth Sciences 27:1431–1450.
OpenUrl Abstract

[76] Parrish R. R.

[77] Ravenhurst C.E.,
Donelick R.A
(1992) in Low Temperature Thermochronology, Fission track thermochronology, eds Zentilli M., Reynolds P.H. Mineralogical Association of Canada short course handbook, pp 21–42.

[78] Ravenhurst C.E.,

[79] Donelick R.A

[80] Roberts D. G.
(1989) Basin inversion in and around the British Isles. in Inversion Tectonics Geological Society, London, Special Publications, eds Cooper M. A., Williams G. D. 44:131–150.
OpenUrl CrossRef

[81] Roberts D. G.

[82] Snee L. W.,
Sutter J. F.,
Kelly W. C.
(1988) Thermochronology of economic mineral deposits: dating the stages of mineralization at Panasqueira by high-precision ⁴⁰Ar/³⁹ Ar age spectrum techniques on muscovite. Economic Geology 83:335–354.
OpenUrl Abstract/FREE Full Text

[83] Snee L. W.,

[84] Sutter J. F.,

[85] Kelly W. C.

[86] Thorpe R. S.
(1987) Permian K-rich volcanic rocks of Devon: petrogenesis, tectonic setting and geological significance. Transactions of the Royal Society of Edinburgh 77:361–366.
OpenUrl

[87] Thorpe R. S.

[88] Willet S.D.
(1992) in Low Temperature Thermochronology, Modelling thermal annealing of fission tracks in apatite, eds Zentilli M., Reynolds P.H. Mineralogical Association of Canada short course handbook, pp 43–72.

[89] Willet S.D.

[90] Willis-Richards J.,
Jackson N. J.
(1989) Evolution of the Cornubian ore field: Part I. Batholith modeling and ore distribution. Economic Geology 84:1078–1100.
OpenUrl Abstract/FREE Full Text

[91] Willis-Richards J.,

[92] Jackson N. J.

[93] Ziegler P. A.
(1987) Celtic Sea-Western Approaches area: an overview. Tectonophysics 137:285–289.
OpenUrl CrossRef Web of Science

[94] Ziegler P. A.

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Geochronological evidence for post-Variscan cooling and uplift of the Carnmenellis granite, SW England

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Geochronological evidence for post-Variscan cooling and uplift of the Carnmenellis granite, SW England

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