Supplementary material
1. Composite depth scale (rmcd) and splice
High-resolution XRF core scanning data measured on multiple holes were used to build a composite depth scale for the site (e.g. Westerhold and Röhl, 2013; Westerhold et al., 2012, Westerhold et al., 2005, Evans et al., 2004). The construction of the composite depth record required several steps. We correlated Fe intensities of Hole 959A (cores 3-9), 959B (cores 3-11) and 959C (cores 4-11) adding constant offsets to the original meter-below-sea-floor (mbsf) scale. No compression or expansion was used. The constant offsets calculated to match the cores of the three holes are presented in Supplementary Table 1. The tie points used to splice the cores over meter composite depth (mcd) have been taken where the cores showed less disturbed Fe intensity data (Supplementary Table 2). The spliced Fe record for Site 959 covers almost 91 meters (from 21.9 to 112.7 rmcd) (Supplementary Fig. 1). To allow locating samples already taken on the new composite depth scale (Westerhold et al., 2012), we adjusted the rmcd depth of the other cores outside the splice for the investigated interval. Where necessary those cores have been ‘stretched’ or ‘squeezed’ using the time-series analysis software package AnalySeries (Paillard et al., 1996) and using the new splice record as reference curve. The revised core depths with the corresponding composite depth and original depth are presented in Supplementary Table 3. The revised depths of the four selected biostratigraphic events and the resulting sedimentation rates are given in Supplementary Table 4. The cyclic patterns in the depth domain were then orbitally tuned in order to develop a high-resolution age model.
Supplementary Table 1. Offsets applied to entire cores for composite record for the three holes drilled at ODP Site 959.
Leg 159Site 959 Hole A / Leg 159
Site 959 Hole B / Leg 159
Site 959 Hole C
Core / mbsf / offset (m) / mcd / Core / mbsf / offset (m) / mcd / Core / mbsf / offset (m) / mcd
3H / 18.60 / 2.90 / 21.50 / 3H / 14.50 / 1.20 / 15.70 / 4H / 21.30 / 1.29 / 22.59
4H / 28.10 / 3.70 / 31.80 / 4H / 24.00 / 1.83 / 25.83 / 5H / 30.80 / 2.65 / 33.45
5H / 37.60 / 4.62 / 42.23 / 5H / 33.50 / 3.07 / 36.57 / 6H / 40.30 / 2.73 / 43.03
6H / 47.10 / 8.95 / 56.05 / 6H / 43.00 / 4.00 / 47.00 / 7H / 49.80 / 4.97 / 54.77
7H / 56.60 / 9.40 / 66.00 / 7H / 52.50 / 4.70 / 57.20 / 8H / 59.30 / 7.64 / 66.94
8H / 66.10 / 10.59 / 76.69 / 8H / 62.00 / 9.61 / 71.61 / 9H / 68.80 / 10.34 / 79.14
9H / 75.60 / 11.24 / 86.84 / 9H / 71.50 / 9.78 / 81.28 / 10H / 78.30 / 10.24 / 88.54
10H / 81.00 / 11.37 / 92.37 / 11H / 87.80 / 11.82 / 99.62
11H / 90.50 / 12.60 / 103.10
Supplementary Table 2: Splice table.
Site / Hole / Core / Sect. / Sect. depth (cm) / mbsf / mcd / Site / Hole / Core / Sect. / Sect. depth (cm) / mbsf / mcdU959 / A / 1 / 7 / 26 / 9.08 / 9.08 / tie to / U959 / A / 2 / 1 / 0 / 9.10 / 10.00
U959 / A / 2 / 8 / 26 / 18.99 / 19.89 / tie to / U959 / A / 3 / 1 / 40 / 19 / 21.90
U959 / A / 3 / 5 / 90 / 25.50 / 28.40 / tie to / U959 / B / 4 / 2 / 107 / 26.57 / 28.40
U959 / B / 4 / 6 / 6 / 31.56 / 33.39 / tie to / U959 / A / 4 / 2 / 9 / 29.69 / 33.39
U959 / A / 4 / 6 / 20 / 35.80 / 39.50 / tie to / U959 / B / 5 / 2 / 143 / 36.43 / 39.50
U959 / B / 5 / 6 / 23 / 41.23 / 44.30 / tie to / U959 / C / 6 / 1 / 127 / 41.57 / 44.30
U959 / C / 6 / 6 / 136 / 49.16 / 51.89 / tie to / U959 / B / 6 / 4 / 39 / 47.89 / 51.89
U959 / B / 6 / 6 / 128 / 51.78 / 55.78 / tie to / U959 / C / 7 / 1 / 101 / 50.81 / 55.78
U959 / C / 7 / 6 / 13 / 57.43 / 62.40 / tie to / U959 / B / 7 / 4 / 70 / 57.7 / 62.40
U959 / B / 7 / 7 / 30 / 61.80 / 66.50 / tie to / U959 / A / 7 / 1 / 50 / 57.10 / 66.50
U959 / A / 7 / 5 / 80 / 63.40 / 72.80 / tie to / U959 / B / 8 / 1 / 119 / 63.19 / 72.80
U959 / B / 8 / 6 / 83 / 70.33 / 79.94 / tie to / U959 / C / 9 / 1 / 80 / 69.60 / 79.94
U959 / C / 9 / 6 / 147 / 77.77 / 88.11 / tie to / U959 / A / 9 / 1 / 127 / 76.87 / 88.11
U959 / A / 9 / 4 / 71 / 80.81 / 92.05 / tie to / U959 / C / 10 / 3 / 51 / 81.81 / 92.05
U959 / C / 10 / 6 / 45 / 86.25 / 96.49 / tie to / U959 / B / 10 / 3 / 112 / 85.12 / 96.49
U959 / B / 10 / 6 / 71 / 89.21 / 100.58 / tie to / U959 / C / 11 / 1 / 96 / 88.76 / 100.58
U959 / C / 11 / 3 / 114 / 91.94 / 103.76 / tie to / U959 / B / 11 / 1 / 66 / 91.16 / 103.76
U959 / B / 11 / 7 / 60 / 100.1 / 112.7 / End of / the / splice
Supplementary Table 3. Mapping pairs of revised composite depth of the cores outside the splice record. Depths in the splice are denoted in italics. Correlation was performed with Analyseries (Paillard et al., 1996) using the splice as reference curve.
159-959A / Splice depth / 159-959B / Splice depth / 159-959C / Splice depthmbsf / mcd / rmcd / mbsf / mcd / rmcd / mbsf / mcd / rmcd
3H / 19 / 21.90 / 21.90 / 3H / 22.16 / 23.36 / 23.32 / 4H / 21.36 / 22.65 / 22.76
25.50 / 28.40 / 28.40 / 22.39 / 23.59 / 23.61 / 21.96 / 23.25 / 23.16
4H / 29.69 / 33.39 / 33.39 / 23.19 / 24.39 / 24.56 / 22.98 / 24.27 / 24.31
35.8 / 39.50 / 39.50 / 23.38 / 24.58 / 24.65 / 23.41 / 24.70 / 24.65
36.33 / 40.03 / 40.12 / 23.92 / 25.12 / 25.14 / 24.10 / 25.39 / 25.29
37.08 / 40.78 / 40.97 / 24.13 / 25.33 / 25.33 / 24.68 / 25.97 / 25.79
37.47 / 41.17 / 41.35 / 4H / 24.27 / 26.10 / 26.08 / 24.98 / 26.27 / 26.08
5H / 38.39 / 43.02 / 42.70 / 24.82 / 26.65 / 26.52 / 25.58 / 26.87 / 26.88
39.33 / 43.96 / 43.64 / 25.39 / 27.22 / 27.06 / 25.78 / 27.07 / 27.06
39.89 / 44.52 / 44.37 / 25.48 / 27.31 / 27.14 / 26.97 / 28.26 / 27.95
42.12 / 46.75 / 46.75 / 25.74 / 27.57 / 27.61 / 27.28 / 28.57 / 28.35
43.13 / 47.76 / 47.87 / 26.57 / 28.40 / 28.40 / 27.53 / 28.82 / 28.47
43.66 / 48.29 / 48.29 / 31.56 / 33.39 / 33.39 / 28.42 / 29.71 / 29.40
45.15 / 49.78 / 50.15 / 31.91 / 33.74 / 33.80 / 29.43 / 30.72 / 30.44
46.49 / 51.12 / 51.78 / 32.54 / 34.37 / 34.51 / 29.66 / 30.95 / 30.71
47.24 / 51.87 / 52.32 / 32.9 / 34.73 / 34.85 / 30.07 / 31.36 / 30.98
6H / 47.97 / 56.92 / 56.50 / 33.44 / 35.27 / 35.46 / 30.46 / 31.75 / 31.41
49.79 / 58.74 / 58.66 / 5H / 34.05 / 37.12 / 37.40 / 5H / 31.23 / 33.88 / 34.05
50.70 / 59.65 / 59.45 / 34.52 / 37.59 / 37.69 / 31.81 / 34.46 / 34.49
51.77 / 60.72 / 60.67 / 35.18 / 38.25 / 38.37 / 34.93 / 37.58 / 37.63
52.24 / 61.19 / 61.12 / 36.43 / 39.50 / 39.50 / 35.74 / 38.39 / 38.38
52.82 / 61.77 / 61.73 / 41.23 / 44.30 / 44.30 / 36.64 / 39.29 / 39.12
54.13 / 63.08 / 62.94 / 42.55 / 45.62 / 45.71 / 37.41 / 40.06 / 40.04
56.34 / 65.29 / 65.38 / 42.73 / 45.8 / 45.91 / 37.70 / 40.35 / 40.32
7H / 56.91 / 66.31 / 66.35 / 6H / 43.42 / 47.42 / 47.05 / 38.62 / 41.27 / 41.24
57.10 / 66.50 / 66.50 / 43.80 / 47.80 / 47.49 / 40.42 / 43.07 / 43.07
63.40 / 72.80 / 72.80 / 44.09 / 48.09 / 47.75 / 6H / 41.57 / 44.30 / 44.30
64.27 / 73.67 / 73.73 / 46.90 / 50.90 / 50.76 / 49.16 / 51.89 / 51.89
64.72 / 74.12 / 74.25 / 47.89 / 51.89 / 51.89 / 49.68 / 52.41 / 52.32
64.97 / 74.37 / 74.67 / 51.70 / 55.70 / 55.70 / 7H / 50.43 / 55.40 / 55.53
65.41 / 74.81 / 75.06 / 51.97 / 55.97 / 55.85 / 50.81 / 55.78 / 55.78
8H / 66.56 / 77.15 / 77.36 / 7H / 52.99 / 57.69 / 58.64 / 57.43 / 62.40 / 62.40
67.63 / 78.22 / 78.28 / 53.88 / 58.58 / 59.33 / 57.86 / 62.83 / 62.76
68.36 / 78.95 / 78.86 / 55.09 / 59.79 / 60.00 / 58.15 / 63.12 / 62.95
68.81 / 79.40 / 79.31 / 55.63 / 60.33 / 60.46 / 8H / 59.51 / 67.15 / 68.27
69.80 / 80.39 / 80.16 / 56.02 / 60.72 / 60.72 / 60.08 / 67.72 / 68.46
70.56 / 81.15 / 80.83 / 56.29 / 60.99 / 60.80 / 60.41 / 68.05 / 68.68
70.71 / 81.30 / 80.94 / 57.25 / 61.95 / 61.70 / 60.64 / 68.28 / 68.97
71.19 / 81.78 / 81.39 / 57.70 / 62.40 / 62.40 / 61.08 / 68.72 / 69.17
72.07 / 82.66 / 82.05 / 60.80 / 66.50 / 66.50 / 61.35 / 68.99 / 69.35
72.45 / 83.04 / 82.38 / 8H / 62.83 / 72.44 / 72.61 / 61.62 / 69.26 / 69.64
73.51 / 84.10 / 83.47 / 63.19 / 72.80 / 72.80 / 62.00 / 69.64 / 70.06
73.74 / 84.33 / 83.78 / 70.33 / 79.94 / 79.94 / 62.45 / 70.09 / 70.63
74.30 / 84.89 / 84.32 / 71.27 / 80.88 / 80.89 / 63.13 / 70.77 / 71.18
74.53 / 85.12 / 84.58 / 71.56 / 81.17 / 81.20 / 63.31 / 70.95 / 71.51
74.75 / 85.34 / 84.86 / 71.66 / 81.27 / 81.30 / 63.71 / 71.35 / 72.03
75.14 / 85.73 / 85.24 / 9H / 73.21 / 82.99 / 83.39 / 64.11 / 71.75 / 72.36
75.69 / 86.28 / 85.81 / 73.78 / 83.56 / 83.83 / 64.77 / 72.41 / 72.62
9H / 76.33 / 87.57 / 87.67 / 74.03 / 83.81 / 84.11 / 65.11 / 72.75 / 72.82
76.87 / 88.11 / 88.11 / 74.86 / 84.64 / 84.86 / 65.40 / 73.04 / 73.03
80.81 / 92.05 / 92.05 / 75.30 / 85.08 / 85.24 / 65.79 / 73.43 / 73.42
82.02 / 93.26 / 93.27 / 76.64 / 86.42 / 86.50 / 66.03 / 73.67 / 73.72
83.65 / 94.89 / 95.15 / 77.10 / 86.88 / 86.92 / 66.71 / 74.35 / 74.23
84.57 / 95.81 / 96.14 / 78.38 / 88.16 / 88.07 / 66.91 / 74.55 / 74.47
78.87 / 88.65 / 88.55 / 67.10 / 74.74 / 74.68
79.83 / 89.61 / 89.58 / 67.87 / 75.51 / 75.42
80.82 / 90.60 / 90.75 / 68.13 / 75.77 / 75.81
81.28 / 91.06 / 91.06 / 68.41 / 76.05 / 76.29
10H / 81.72 / 93.09 / 93.14 / 68.95 / 76.59 / 76.58
82.38 / 93.75 / 93.59 / 9H / 69.60 / 79.94 / 79.94
82.85 / 94.22 / 94.27 / 77.77 / 88.11 / 88.11
85.12 / 96.49 / 96.49 / 78.23 / 88.57 / 88.51
89.21 / 100.58 / 100.58 / 10H / 79.33 / 89.57 / 89.59
89.27 / 100.64 / 100.65 / 80.98 / 91.22 / 91.29
90.20 / 101.57 / 101.72 / 81.81 / 92.05 / 92.05
90.50 / 101.87 / 102.04 / 86.25 / 96.49 / 96.49
11H / 91.05 / 103.65 / 103.63 / 86.66 / 96.90 / 97.01
91.16 / 103.76 / 103.76 / 86.89 / 97.13 / 97.25
100.10 / 112.70 / 112.70 / 87.49 / 97.73 / 97.86
11H / 88.76 / 100.58 / 100.58
91.94 / 103.76 / 103.76
92.27 / 104.09 / 104.13
93.47 / 105.29 / 105.23
93.58 / 105.40 / 105.50
94.38 / 106.20 / 106.29
95.19 / 107.01 / 106.95
95.54 / 107.36 / 107.38
96.36 / 108.18 / 108.16
97.00 / 108.82 / 108.80
97.33 / 109.15 / 108.98
Supplementary Table 4. Selected biostratigraphic events used for preliminary calculation of SR.
Age (Ma)1 / HOLE / mbsf / rmcd (this study) / SR(cm/kyr)
HO Discoaster brouweri* / 1.926 / C / 25 / 26.12±0.12 / 1.43
HO Reticulofenestra pseudoumbilica* / 3.700 / C / 48.9 / 51.63±0.1 / 1.44
HO Discoaster quinqueramus* / 5.590 / B / 83.84 / 95.24±0.73 / 2.31
FAD Globorotalia margaritae** / 6.080 / C / 94.1 / 106.7±0.1 / 2.34
1Age for the biostratigraphic events are from Gradstein et al. (2012)
* after Shin et al., (1998), Shin (1998), Shafik et al. (1998)
** after Norris (1998).
2. Cyclostratigraphy and orbital tuning
Following the metronome method of Herbert et al. (1995) we built a cyclostratigraphy by counting of cycles in the Fe data after filtering using a Gaussian band-pass filter (Supplementary Fig. 2). We filtered the Fe record at the eccentricity frequencies with a 30% bandwidth. We started counting eccentricity cycles at the first cycle before the Highest Occurrence (HO) of Discoaster brouweri (Shin et al. 1998; Shin, 1998) at 26.12 rmcd. Counting cycles was straightforward for most of the sequence except for the interval between cycle 16 and 24 were amplitudes were smaller. We counted 43 short eccentricity cycles (Supplementary Fig. 2) which correspond to a record of 4.3 Ma, assuming an average duration of 100 kyr.
We preliminary tuned the Fe intensity data to the eccentricity curve La2004 (Laskar et al., 2004) correlating the minima in the eccentricity long cycles, 405 kyr (Laskar et al., 2004) to the minima in the Fe cycles (Supplementary Fig. 3). For fine-tuning we used the sum of normalized Eccentricity, Tilt and Precession (E+T-P) based on La2004 solution (Laskar et al. 2004) as a target curve. Fe maxima were tuned to ETP maxima or Fe minima to ETP minima applying a minimum number of tie-points (Table 3 of main text).
To verify the accuracy of our age model we compared the benthic oxygen isotope record at Site 959 (Norris, 1998) and several other tuned oxygen isotope records of ODP Sites 846, 926, 982 (Shackleton et al., 1995; Shackleton and Crowhurst, 1997; Hodell et al., 2001), and the benthic oxygen isotope stack LR04 (Lisiecki and Raymo, 2005). The heavy Marine Isotope Stages CN6, Si6 and TG20 are well recognised and aligned as are the light Isotope Stages T5 and T7 (terminology after Shackleton et al., 1995). The major stepwise deglaciation from TG14 to TG9 is also recognised. However, resulting ages of Stages TG8 through TG14 are about 50 ka older at Site 959 than at Sites 926 and 982 (Supplementary Fig. 4).
References Supplementary materials
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