Table 1.

Apatite fission-track analysis sample details

Sample numberSample location (depth b.s.l. if offshore)Stratigraphic age (Ma)Uranium content (ppm)Fission-track age (Ma ± 1σ)*P(S2) (number of grains)Mean track length (μm)S.D. (μm) (number of track lengths)
West Orkney Basin
GC523-24BGS rockdrill 58-06/642 (4.7 m)Permian–Triassic (299–200)476.5 ± 13.717 (20)12.12 ± 0.602.55 (18)
GC503-146BGS BH72/37 (9–21 m)Triassic (251–200)17239.3 ± 22.8<1 (19)11.90 ± 0.191.87 (100)
GC503-147BGS BH73/31 (28–31 m)Permian–Triassic (299–200)9300.4 ± 23.9<1 (20)10.98 ± 0.202.04 (100)
GC503-148BGS BH72/34 (14 m)Early Jurassic (200–176)12201.5 ± 32.1<1 (12)11.26 ± 0.352.48 (51)
GC503-149BGS BH73/29 (31–36 m)Permian–Triassic (299–200)13281.5 ± 15.214 (20)11.50 ± 0.171.83 (118)
GC503-150BGS BH72/25 (15–19 m)Permian–Triassic (299–200)10295.8 ± 23.7<1 (20)11.88 ± 0.171.74 (101)
GC503-151BGS BH78/07 (125–128 m)Permian–Triassic (299–200)10428.6 ± 33.0<1 (20)11.54 ± 0.181.84 (109)
202/19-1
GC503-84274–427 mLate Permian (260–251)22138.6 ± 17.7<1 (20)12.27 ± 0.232.00 (75)
GC503-85610–762 mLate Permian (260–251)13162.5 ± 19.3<1 (20)13.21 ± 0.191.77 (84)
GC503-86975–1128 mLate Permian (260–251)15138.1 ± 17.0<1 (20)12.30 ± 0.282.11 (57)
GC503-871372–1524 mLate Permian (260–251)1082.5 ± 9.16 (20)11.88 ± 0.511.52 (9)
GC503-881753–1758 mLate Permian (260–251)2865.8 ± 4.95 (20)12.99 ± 0.161.23 (56)
GC503-891810–1819 mLate Permian (260–251)23107.8 ± 16.6<1 (20)12.81 ± 0.331.58 (23)
GC503-901999–2008 mLate Permian (260–251)1770.1 ± 8.593 (20)11.82 ± 0.601.88 (10)
GC503-912316–2469 mLate Permian (260–251)2658.5 ± 7.2<1 (20)12.03 ± 0.311.60 (27)
GC503-922743–2895 mLate Permian (260–251)2157.4 ± 6.0<1 (20)11.08 ± 0.622.24 (13)
Hebrides
GC503-184BalchrickTorridonian (1000–530)24176.4 ± 15.7<1 (20)12.41 ± 0.242.36 (100)
GC503-185Tolm, LewisPermian–Triassic (299–200)20212.1 ± 16.0<1 (20)12.11 ± 0.282.10 (58)
GC523-11BGS BH71/11 (19–25 m)Permian–Triassic (299–200)12119.2 ± 13.2<1 (20)10.88 ± 0.292.65 (82)
GC523-13BGS BH71/13 (14.5–15 m)Torridonian (1000–530)15133.2 ± 32.0<1 (15)10.08 ± 0.542.21 (17)
GC523-14BGS BH71/14 (23–27 m)Permian–Triassic (299–200)1172.2 ± 18.8<1 (13)11.05 ± 0.953.16 (11)
GC523-15BGS BH72/32 (28–36 m)Permian–Triassic (299–200)8139.5 ± 23.04 (13)12.08 ± 0.522.50 (23)
GC523-23BGS rockdrill 58-08/94 (1.85–2.6 m)Permian–Triassic (299–200)17160.1 ± 15.0<1 (19)11.63 ± 0.262.68 (106)
GC523-47BGS BH78/05 (54 m)Permian–Triassic (299–200)7187.7 ± 17.213 (20)12.68 ± 0.191.93 (104)
GC523-48BGS BH88/04 (11.15–12.61 m)Permian–Triassic (299–200)11184.3 ± 22.7<1 (20)12.37 ± 0.222.30 (106)
GC523-49BGS BH88/08 (11.5–12.1 m)Permian–Triassic (299–200)13219.8 ± 20.23 (20)11.45 ± 0.272.75 (106)
GC523-51BGS BH90/08 (17.25–12 m)Late Jurassic (161–145)27270.3 ± 27.5<1 (20)12.11 ± 0.171.91 (125)
GC523-52BGS BH90/09 (18–22.3 m)Early Cretaceous (145–100)7220.8 ± 19.071 (20)12.35 ± 0.261.52 (34)
GC523-55BGS BH90/14 (91 m)Lewisian (>2500)18238.9 ± 22.1<1 (20)12.89 ± 0.151.65 (114)
GC523-56BGS BH90/16 (75–76.5 m)Permian–Triassic (299–200)9215.7 ± 16.97 (20)11.80 ± 0.312.40 (62)
GC523-80Dornie, Loch DuichMoine (1100–800)15227.3 ± 15.221 (20)11.39 ± 0.262.68 (106)
GC523-93Luskentyre, HarrisLewisian (>2500)470.8 ± 9.217 (20)14.25 ± 0.691.70 (6)
GC523-95Northton, HarrisLewisian (>2500)11201.4 ± 11.322 (20)14.40 ± 0.151.48 (102)
GC523-97Meavag, HarrisLewisian (>2500)4180.9 ± 15.370 (20)12.95 ± 0.362.13 (35)
GC523-98Bowglass, HarrisLewisian (>2500)6216.7 ± 15.217 (20)13.91 ± 0.121.26 (111)
GC523-110Achmelvich BayLewisian (>2500)2147.7 ± 26.875 (20)11.79 ± 0.352.37 (46)
GC523-111Loch LurgainnTorridonian (1000–530)18296.1 ± 33.6<1 (7)12.15 ± 0.252.20 (77)
GC523-112Gruinard BayLewisian (>2500)1234.2 ± 76.789 (20)12.13 ± 0.851.90 (5)
134/5-1
GC523-58579–731 mPliensbachian (190–183)13256.7 ± 41.39 (5)12.11 ± 0.420.84 (4)
GC369-1930–1082 mSinemurian (197–190)2681.1 ± 37.6<1 (5)10.11 ± 1.884.20 (5)
GC369-21524–1676 mHettangian–Sinemurian (200–190)1657.7 ± 33.0<1 (4)14.30 ± 0.270.38 (2)
GC523-681829–1966 mTriassic (251–200)974.5 ± 37.5<1 (8)12.46 ± 0.451.09 (6)
GC369-31966–2079 mTriassic (251–200)1619.6 ± 4.9<1 (19)10.30 ± 0.351.88 (29)
GC369-42164–2255 mTriassic (251–200)338.7 ± 2.1<1 (22)11.24 ± 0.471.04 (5)
GC369-52255–2347 mTriassic (251–200)327.6 ± 0.814 (20)10.54 ± 0.793.06 (15)
Skye, Mull and Morvern
GC523-1Loch Aline, MorvernTriassic (251–200)18229.2 ± 13.663 (20)10.66 ± 0.212.13 (102)
GC523-2Loch Aline, MorvernMoine (1100–800)18206.4 ± 14.352 (20)10.43 ± 0.212.25 (110)
GC523-3Loch Aline, MorvernTriassic (251–200)18208.1 ± 12.369 (20)10.75 ± 0.212.17 (107)
GC523-4Loch Aline, MorvernCenomanian (100–94)21221.2 ± 14.579 (20)10.99 ± 0.222.18 (102)
GC523-5Loch Aline, MorvernCenomanian (100–94)15219.2 ± 18.2<1 (17)10.82 ± 0.372.19 (35)
GC523-6GlenancrossMoine (1100–800)859.5 ± 7.698 (20)11.43 ± 0.272.70 (103)
GC523-8GlenancrossMoine (1100–800)15177.8 ± 11.521 (20)10.82 ± 0.232.29 (103)
GC523-9BGS BH71/09 (42–46 m)Devonian (416–359)5231.1 ± 23.023 (20)10.87 ± 0.272.01 (57)
GC523-10BGS BH71/10 (20–22 m)Jurassic (200–145)2660.6 ± 15.7<1 (14)13.04 ± 0.171.83 (115)
GC523-71Ganavan BayEarly–Middle Devonian (416–385)11228.4 ± 26.5<1 (19)12.08 ± 0.242.30 (88)
GC523-72Inninmore Bay, MorvernViséan (345–328)13157.0 ± 11.033 (20)10.83 ± 0.422.80 (44)
GC523-74Inninmore Bay, MorvernViséan (345–328)10142.6 ± 14.5<1 (20)10.53 ± 0.333.44 (108)
GC523-77Fionnphort, MullDevonian (416–359)7203.7 ± 16.99 (20)11.48 ± 0.222.20 (101)
GC523-78Bunessan, MullMoine (1100–800)24151.6 ± 9.128 (20)10.12 ± 0.262.75 (110)
GC523-79Balnahard, MullTriassic (251–200)1167.9 ± 5.520 (20)12.58 ± 0.222.27 (102)
GC523-83Broadford Bay, SkyeEarly Jurassic (200–176)2152.3 ± 6.0<1 (20)13.53 ± 0.291.66 (32)
GC523-84Broadford Bay, SkyeEarly Jurassic (200–176)1654.7 ± 4.73 (20)13.91 ± 0.241.53 (40)
GC523-88Drocaid Lusa, SkyeTorridonian (1000–530)2361.9 ± 4.419 (20)13.43 ± 0.412.20 (29)
GC523-89Loch Slapin, SkyeMiddle Jurassic (176–161)1271.2 ± 8.2<1 (20)14.39 ± 0.231.55 (45)
GC523-91Cairidh Ghlumaig, SkyeMiddle Jurassic (176–161)13219.2 ± 18.4<1 (20)12.11 ± 0.302.53 (72)
GC523-99Staffin, SkyeMiddle Jurassic (176–161)2266.4 ± 4.99 (20)13.92 ± 0.270.99 (13)
GC523-102Culnacnoc, SkyeMiddle Jurassic (176–161)1968.0 ± 6.5<1 (20)14.14 ± 0.181.12 (39)
GC523-105CuaigTorridonian (1000–530)2660.6 ± 15.7<1 (14)12.60 ± 0.322.44 (60)
GC523-106ApplecrossEarly Jurassic (200–176)13275.7 ± 18.98 (19)10.85 ± 0.202.11 (108)
GC523-108ApplecrossPermian–Triassic (299–200)16179.6 ± 34.6<1 (10)10.19 ± 0.432.21 (27)
GC523-109ApplecrossTorridonian (1000–530)13270.9 ± 22.24 (20)10.35 ± 0.262.69 (108)
RD17-41 Fort AugustusMoine (1100–800)29179.8 ± 10.6<1 (20)11.98 ± 0.141.41 (104)
RD17-42Strontian (A884)Strontian Granite (420)37207.9 ± 8.596 (20)11.76 ± 0.131.43 (120)
RD17-43Coire nam Muc (A884)Moine (1100–800)36213.7 ± 9.123 (20)11.89 ± 0.141.48 (109)
RD17-44Beinn Chlaonleud (A884)Strontian Granite (420)32187.7 ± 9.210 (20)11.96 ± 0.111.13 (100)
RD17-45Beathrach (A884)Strontian Granite (420)32195.1 ± 13.0<1 (20)12.02 ± 0.111.08 (102)
RD17-46Beathrach (A884)Strontian Granite (420)32204.1 ± 12.3<1 (20)12.14 ± 0.121.28 (108)
RD17-47Liddesdale (A884)Strontian Granite (420)30202.9 ± 12.6<1 (20)12.28 ± 0.131.27 (101)
RD17-48Liddesdale (A884)Strontian Granite (420)28188.6 ± 11.1<1 (20)12.02 ± 0.141.40 (100)
  • *Central age (Galbraith & Laslett 1993) used for samples containing a significant spread in single grain ages (P(S2) > 5%), otherwise the ‘pooled age' is quoted. All ages were calculated using the zeta calibration approach of Hurford & Green (1983) using zeta values of 336.0 ± 6.0 for samples GC369-1 to -5 (SRM612 dosimeter glass), 380.4 ± 5.7 for samples GC503-84 to -92 (CN5 dosimeter glass), 354.8 ± 6.3 for GC503-184 and -185 (SRM612), 386.9 ± 6.9 for GC523-88 to -102 (CN5), 378.4 ± 5.5 for GC503-146 to -151 (CN5), 392.9 ± 7.4 for GC523-1 to -84 and GC523-105 to -112 (CN5), 348.8 ± 5.2 for RD17-41 and 44-48 (SRM612), and 360.3 ± 6.8 for RD17-42 and -43 (SRM612). All errors quoted at ±1σ. All analytical details are as described by Green et al. (2001), with the exception that the thermal neutron irradiation showed a significant flux gradient, and the appropriate value of ρD was determined by linear interpolation through the stack of grain mounts.