Table 1. Apatite fission-track data measured for Hole 976B Alboran Sea samples.
 
Sample
Depth (mbsf)
Rock type
No. of crystals
Dosimeter
Spontaneous
Induced
Age dispersion
Central age (Ma)
▒ 1
Mean track length (Ám) ▒ 1 standard error
Mean track length standard deviation
No. of tracks
d
Nd
s
Ns
i
Ni
P2
RE%
161-976B-














77R-2 (Piece 3B) 685.83 Calc-silicate (Inadequate apatite separated—no analysis possible.)
83R-1 (Piece 11A) 727.66 Calc-silicate (Apatites full of inclusions—no analysis possible.)
92R-1 (Piece 10) 785.26 Calc-silicate 23 1.397 7745 0.203 149 2.335 1712 26 8.9 20.7 ▒ 1.8 14.25 ▒ 0.15 0.83 31
95R-2 (Piece 1D) 814.89 Gneiss 22 1.397 7745 0.139 104 1.540 1146 85 0.5 21.5 ▒ 2.2 14.23 ▒ 0.30 1.07 14
95R-2 (Piece 3) 815.3 Leucosome 20 1.397 7745 0.146 210 1.858 2670 97 0 18.6 ▒ 1.4 14.54 ▒ 0.13 1.26 96
96R-1 (Piece 4A) 823.05 Gneiss 20 1.397 7745 0.156 96 1.725 1064 61 4.8 21.4 ▒ 2.3 14.78 ▒ 0.21 1.01 24
97R-1 (Piece 7) 833.05 Gneiss 20 1.397 7745 0.144 81 1.723 972 87 0 19.7 ▒ 2.3 14.31 ▒ 0.23 1.11 24
97R-2 (Piece 1) 834.07 Schist/gneiss 20 1.397 7745 0.200 111 2.704 1499 27 16.5 17.8 ▒ 1.9 13.83 ▒ 0.24 1.29 29
97R-2 (Piece 22) 835.34 Granite 20 1.397 7745 0.200 170 2.445 2077 68 0.9 19.4 ▒ 1.6 14.30 ▒ 0.18 0.95 28
98R-1 (Piece 5) 842.36 Migmatite 20 1.397 7745 0.210 152 3.276 2370 95 0 15.2 ▒ 1.3 14.34 ▒ 0.20 1.11 33
98R-2 (Piece 2) 844.23 Neosome 20 1.397 7745 0.182 194 2.450 2611 91 0 17.8 ▒ 1.3 14.65 ▒ 0.14 1.15 71
102R-2 (Piece 10B) 882.76 Leucosome 20 1.397 7745 0.186 187 2.584 2593 69 0.2 17.1 ▒ 1.3 14.28 ▒ 0.11 0.91 65
104R-1 (Piece 10) 900.69 Calc-silicate 8 1.380 7252 0.168 36 1.936 416 96 0 19.2 ▒ 3.3
No lengths—many inclusions.

Notes: Basement/sediment interface is 669.73 m below seafloor, d,s, i = track densities (x 106 tr cm-2); Nd,s, i = numbers of tracks counted. Spontaneous and induced: analyses by external detector method using 0.5 for the 4/2 geometry correction factor. P2 is probability of obtaining 2 value for v degrees of freedom, where v = no. crystals - 1. Central age is a modal age, weighted for different precisions of individual crystals (see Galbraith and Laslett, 1993); ages calculated using dosimeter glass CN-5; analyst Carter CN5 =339 calibrated by multiple analyses of IUGS-recommended apatite and zircon age standards (see Hurford, 1990).